civil engineering

Journal of Current Construction Issues

CIVIL ENGINEERING PRESENT PROBLEMS, INNOVATIVE SOLUTIONS

- Civil Engineering in XXI Century

BYDGOSZCZ - POLAND – 2018

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The Journal was commissioned by the UTP University of Science and Technology, Bydgoszcz, Poland

Reviewers: dr hab. in . Jadwiga Bizon-Górecka, prof. UTP dr hab. Iwona Posadzi ska, prof. UTP Scientific editor: dr in . Jarosław Górecki Technical editor: mgr in . Ewa Górecka

All chapters were peer reviewed.

ISBN 978-83-87480-06-6 Publisher: BGJ-Consulting, ul. Zaj cza 6/53 ; 85-809 Bydgoszcz

Bydgoszcz - Poland - 2018

Printing house: Drukarnia REKPOL; www.rekpol.eu

CEPPIS 2018 supported by the European Council of Civil Engineers (ECCE) and listed in the Calendar of the 2018 European Year of Civil Engineers (2018 EYCE)

CIVIL ENGINEERING – PRESENT PROBLEMS, INNOVATIVE SOLUTIONS – Civil Engineering in XXI Century

CONTENTS:

Page

PREFACE......................................................................................................

7

Chapter 1

USE

OF

RICE

HUSK

IN

CONCRETE:

REVIEW

OF

MECHANICAL PROPERTIES - Adeyemi ADESINA .........................

15

Chapter 2

OVERVIEW

OF

CONCRETE

THE

MECHANICAL

INCORPORATING

PROPERTIES

WASTE

FROM

OF THE

CONCRETE INDUSTRY AS AGGREGATE - Adeyemi ADESINA ..

23

Chapter 3

REVIEW

ON

CONSTRUCTION

PROJECT

MANAGER

SELECTION CRITERIA AND METHODS - Ali Reza AFSHARI ….

37

Chapter 4

FORSIGHT AND TRENDS IN CONSTRUCTION PROJECT MANAGEMENT - Rıfat AKBIYIKLI, S.Ümit D KMEN, Latif Onur U UR, Ali ATE ………………………..………………………………

49

Chapter 5

RISK MANAGEMENT IN PRIVATE FINANCE INITIATIVE (PFI) ROAD PROJECTS: A ROAD CASE IN THE UK - Rifat AKBIYIKLI, S. Ümit D KMEN, David EATON …………………..........

57

Chapter 6

DETERMINATION OF DESIGN EARTHQUAKE MAGNITUDE BY DETERMINISTICAL APPROACH IN DUZCE DISTRICT, TURKEY - Ali ATE …………………………………………………....

85

Chapter 7

INVESTIGATION OF DAMPING ACCELERATION RATIO AND SITE EFFECTS ON SEISMIC GROUND RESPONSE IN THE DUZCE REGION, TURKEY - Ali ATE , Latif Onur UGUR, Rifat AKBIYIKLI, Inan KESKIN, Burak YE IL, Caner DEMIRDAG ...........

97

Chapter 8

RISK

FACTORS

FOR

THE

LIFE

CYCLE

OF

THE

CONSTRUCTION INVESTMENT PROJECT - Jadwiga BIZONGÓRECKA, Jarosław GÓRECKI …………………..................................

111

Chapter 9

PREFABRICATION OF BUILDING SERVICES - Anna CHODOR .

121

Chapter 10

LEAN CONSTRUCTION IN ROAD PROJECTS

- Ahmed

ELKHERBAWY, Jose-Antonio LOZANO, Gonzalo RAMOS, Jose TURMO ………………………………….………………………………

147

Chapter 11

COMPARISON OF PROJECT MANAGEMENT AND LEAN CONSTRUCTION IN A REAL ROAD PROJECT - Ahmed ELKHERBAWY, Jose-Antonio LOZANO, Gonzalo RAMOS, Jose TURMO …………………………………………………………………

167

Chapter 12

SUSTAINABLE PRODUCTION: REVIEW OF EUROPEAN TRENDS - Jarosław GÓRECKI, Eugeniusz SWOI SKI, Jadwiga BIZON-GÓRECKA ……………………………………………………...

199

Chapter 13

THE EVOLUTIONARY COMPUTATION ON THE MARKET. THE COMPETITION AN EQUILIBRIUM IN SALE COSTS AND QUANTITIES - Oleg TSARKOV………………… ……………...........

213

Chapter 14

SELECTION

OF

ARCHITECTURE

COMPANY

WITH

PROMETHEE METHOD - Latif Onur U UR…………... .…………..

239

Chapter 15 INVESTIGATION OF SKELETON CONSTRUCTION COSTS OF VILLA BUILDINGS WITH DIFFERENT CARRIER SYSTEMS Latif Onur U UR, Rıfat AKBIYIKLI, Ali ATE ……………………….

259

Chapter 16 OPTIMUM DESIGN OF COMPOSITE STEEL I-GIRDER BRIDGES - Fatma ÜLKER, Ragıp NCE ……………………………… 275

[ Preface ] „ Every action has its pleasures and its price.” -Socrates

T

he Journal of Current Construction Issues. Civil engineering in 21st century, the next number in turn, was written on the basis of an increased interest in the contemporary problems in building

sector and a recently intensified discourse about making better decisions connected with whole life-cycle of construction projects. As it was stated in the first number of the Journal (Sustainable Development in Construction), a term project relates to an original undertaking which has a specific aim, clear start/finish dates and all resources are allocated to particular tasks. Today, it is crucial to coordinate all activities of stakeholders involved in the undertaking. Construction projects usually involve many stakeholders who can

be classified into some categories (e.g. internal and external). All these stakeholders require some helpful, practical (ready-to-use) and optimal recommendations for decision making. A construction project consists of three basic flows (design process, material process and work process) and supporting flows1. Although more than 25 years have passed since Lauri Koskela described Koskela L. CIFE Techical Report #72 (1992)

8

Jarosław Górecki

these words, the statement is still valid. The report in which it was put was entitled: "Application of the new production philosophy to construction". According to the same author the new philosophy refers to “an evolving set of methodologies, techniques and tools, the genesis of which was in the Japanese JIT and TQC efforts in car manufacturing". After the quarter century, can we say with full awareness and responsibility that everything has come true? Why is it so difficult to implement process and organizational innovations in a building sector? And finally why something, what has been consistently and successfully implemented in the automotive industry, may not work in the construction industry? Perhaps that new philosophy required certain product innovations (e.g. nanomaterials, graphene, fiber-reinforced materials, space technology, products which have not been discovered yet, etc.) and new technological solutions (e.g. modern prefabrication, Big Data and artificial intelligence, drones, BIM, 3D printing, etc.) to be successful? Are we aware of this? Are we aware of what changes and challenges await the construction industry? Complex construction projects usually involve large capital investments, take a long time, and are characterized by dynamic changes that cause the risk of project. A changeability of construction circumstances has been considered as a source of the project risk. The project stakeholders need to be equipped with some innovative tools that can be useful in the project management especially in the project risk management. Challenges of civil engineering and construction management in 21st century has been included in a series of annual conferences organized

9

Preface

by the UTP University of Science and Technology in Bydgoszcz. The fourth international scientific conference Civil Engineering: Present Problems, Innovative Solutions (CEPPIS) in 2018 was set out to pay attention to prospective trends in civil engineering especially to answer a bothering the question how will the future of building sector look like if majority of predictions connected with this branch of industry come true? This book was written in order to present some theoretical and practical

considerations,

experience

and

results

of

conducted

investigations in the area of project management with challenges of civil engineering and possible breakthrough transformations in the background. A complexity of the project management in construction industry was described in the book. This attitude results from a need for using available resources more effectively while maintaining an economic activity. It is also essential because of a necessity of protecting natural elements of the environment for next generations along with a need for making optimal decisions. However, these problems were discussed during the CEPPIS conferences in 2016 and 2017 and described in two previous issues of the Journal of Current Construction Issues. The book is addressed to the scientists connected with construction project management discipline as well as to those who are responsible for creating risk registers for construction projects. A presented matter can become a source of inspiration for the academics involved in the optimization processes in the building sector and for those who are looking for some new solutions and more efficient management strategies for construction projects (e.g. lean construction).

10

Jarosław Górecki

Professional project managers should be interested in the issue. Some implementations can be useful for them in order to solve their contemporary problems in real circumstances. The issue may also inspire them to evolve towards assurance of new needs emerging in the 21st century. Particular chapters present studies results of the scientists researching on business, construction engineering, project management and innovations in construction from all over the world. I would like to thank everyone who was engaged in preparation of the CEPPIS 2018 conference: scientific and organizing committees for their contribution. Thank you being so selfless. I want to thank all participants

of

international

scientific

conferences

Civil Engineering: Present Problems, Innovative Solutions (CEPPIS) in the past and in the future for their extraordinary collaboration and true commitment in the popularization of their ideas connected with project management. It is high time to thank all authors of the chapters and reviewers, especially the book reviewers – Prof. Jadwiga Bizon-Górecka and Prof. Iwona Posadzi ska from UTP University of Science and Technology in Bydgoszcz – for their magnificent support in successful publishing the Journal of Current Construction Issues. The next issue of the Journal will feature selected chapters from CEPPIS 2019 on other topics related to project management and current problems in the construction industry.

11

Preface

I would like to encourage to leave feedback from the readers of the

book.

Please

[email protected].

send

your

comments

directly

to

me

at

Adeyemi ADESINA Concordia University Building, Civil, and Environmental Engineering

USE OF RICE HUSK IN CONCRETE: REVIEW OF MECHANICAL PROPERTIES

Keywords: green material; rice husk ash; sustainability; concrete

Abstract Recently, there has been huge interest in the use of supplementary cementitious materials (SCMs) as a partial replacement for ordinary Portland cement (OPC) in concrete. This urge to replace OPC is due to the high carbon dioxide emitted into the environment during its production. Rice husk ash (RHA) is one of the types of SCM that can be used to replace OPC in concrete, and it is the waste product of rice production. This paper presents a detailed and recent review of the mechanical properties reported by various studies. It was concluded that with the right proportion of RHA incorporated into concrete, enhanced mechanical properties can be achieved. In addition, the use of RHA in concrete reduces the overall embodied carbon of the concrete, while reducing cost and utilizing waste generated by the agricultural industry.

1.

Introduction

Concrete is the most consumed building material in the world, and the second most used material after water. As billions of tons of concrete are produced annually, a correspondingly large amount of materials is being consumed. And the concrete industry has been ascribed to the industry that consumed the highest amount of natural resources. Apart from the depletion of these natural resources, the production of ordinary Portland cement (OPC) which is the main binder in concrete is one of the major contributors to the world's human-induced carbon dioxide. And more carbon emission from OPC production is expected due to the exponential increase in the demand for concrete/cement predicted for coming years. Therefore, there is an urgent need for the concrete industry to find to reduce or replace the amount of natural resources including OPC used in concrete. Several ways such as partial to total replacement of OPC, use of waste materials as aggregate in concrete, use of wastewater, etc., have been explored over the years. One of the major ways to reduce the embodied carbon of concrete is by partial replacement of OPC with supplementary cementitious

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Adeyemi Adesina

materials. SCMs are mostly waste materials that possess pozzolanic and hydraulic properties. SCMs such as fly ash, slag, silica fume, metakaolin, rice husk ash (RHA), etc., have been used as a partial replacement over the decades. Use of SCMs in concrete also creates an avenue to manage these waste, thereby preventing any negative impact that could be made on the environment as a result of their disposal. These SCMs have varying effects on the fresh and hardened properties of concrete, and proper selection of type and OPC replacement level has been reported to be the most effective way to incorporate these waste materials into concrete. RHA which is a type of SCM and an agricultural waste has been found to enhance both mechanical and durability properties of concrete. RHA is a preferred SCM compared to that of fly ash and silica fume due to its high reactivity and silica content. The high reactivity of RHA is associated with its large surface area and high amount of amorphous silica [1,2]. Incorporation of RHA as SCM into concrete has been reported to create a less permeable matrix and induce high early strength. However, in order to incorporate RHA into concrete, it must meet the requirements of ASTM C618 [3]. ASTM C618 requirements stated that the loss of ignition (LOI) of the RHA must not be 12% maximum, and the summed composition of aluminum dioxide, iron oxide, and silicon dioxide must not exceed 70%. To foster more research and utilization of RHA as a partial replacement for OPC in concrete, this paper gathers the results of several studies on the application of RHA in concrete. The main objective of this paper is to explore the effect of incorporation of RHA into concrete, focusing on its effect on the major mechanical properties of concrete. It is anticipated that this review will serve as a guidebook for several researchers working on making the construction industry more sustainable in terms of building materials. This review will also be a propeller for more research and development in the use of RHA in concrete.

2.

Sources and processing of rice husk ash

RHA is a waste product from the agricultural industry. RHA is obtained by burning of rice husk at elevated temperatures. The type of RHA produced is dependent on the time and temperature of burning. Also, the chemical and physical properties of the produced RHA is determined by the climate of the region where the rice was grown, the composition of the soil, and type of paddy [4]. Multhadhi et al. [5] and Maeda et al [6] also found out that the type of fertilizer used might affect the produced RHA. Silica content in RHA is in the range of 85% to 95%, however the silica content in the rice husk before burning is about 20% by weight of the rice husk. About one-fourth by mass of RHA is produced with every quantity of rice husk combusted, and rice husk is about one-fifth the amount of rice paddy milled.

Use of rice husk in concrete: review of mechanical properties

3.

Mechanical properties

3.1

Compressive strength

17

Compressive strength of concrete is the major mechanical properties of concrete, and all other mechanical properties are related to it. Earlier studies showed that concrete with no RHA has been reported to have higher compressive strength than those with RHA at replacement levels from 20 to 30% [7]. Concrete incorporating no SCM and those with silica fume (SF) as 10% replacement of OPC have reported a higher compressive strength compared to those incorporating RHA at the same replacement level [8]. However, Wada et al. [9] reported a contradicting result indicating concrete incorporating RHA has a higher compressive strength compared to those without RHA. Higher compressive strength up to 91 days was also reported by De Sensale [10]. He also concluded that a 20% replacement level of OPC with RHA produced the highest compressive strength. The study by Habeeb and Mahmud [11] also supported that the maximum OPC replacement level with RHA as 20%, as there might be detrimental effects on the properties of concrete after this replacement level. Replacement level of OPC with RHA less than 5% has been found to be insufficient to improve the early age compressive strength of [11]. This has been attributed to the low amount of silica available in the pore structure to react with the calcium hydroxide, thereby producing less amount of calcium silicate hydrate. However, at later ages; concrete with 5% replacement level of OPC with RHA was found to have compressive strength compared to the control without RHA. Habeeb and Mahmud [11] concluded from their study that the optimum OPC replacement level with RHA is 10% as there’s reduction in compressive strength below and above this level at later ages. The decrease in compressive strength at levels above 10% was ascribed to excess silica available to react with the produced calcium hydroxide in the cementitious matrix. The unreacted silica will be left in the matrix has a stable material and will not contribute to any chemical reaction. However, at 20% replacement level of OPC with RHA, the compressive strength achieved was similar to that of OPC. The effect of replacement level of OPC with RHA on the compressive strength of concrete is presented in Fig. 1. It will be observed from Fig. 1 that the compressive strength of all mixes increases with age. However, replacement level of 10% has the highest compressive strength at all ages. Kartini [12] also suggested the optimum replacement level of OPC with RHA to be 10% as a decrease in compressive strength was observed when the amount of RHA increased.

18

Adeyemi Adesina

Fig. 1. Effect of RHA replacement levels and age on compressive strength (data from [11]) Though for all particle size of RHA, a similar higher compressive strength was reported at early ages. However, at later ages; concrete with finer particle size exhibited higher strength [11]. This higher strength has been reported to be as a result of an increase in fineness which increased the reactivity of the RHA, thereby producing more products (i.e. calcium silicate hydrate) when reacted with the calcium hydroxide in the concrete’s pore solution. Production of more reaction products leads to densification of the concrete matrix, directly increasing the strength of the concrete. Also, increase in strength associated with concrete with finer RHA can be as a result of the RHA acting as a micro-filler, thereby improving the cement microstructure. Earlier studies by Ismail and Walliuddin [13] on high strength concrete also observed similar results when finer RHA was used as a partial replacement for OPC.

3.2

Split tensile strength

Concrete is strong in compression but weak in tension. However, enhancing the tensile strength of concrete is essential in applications where the load will pose a tensile force on the concrete element. The tensile strength of concrete is determined using the split tensile test. Higher split tensile strength has been reported for incorporation of RHA as a partial replacement of OPC in concrete [10]. The higher tensile strength has been ascribed to the pozzolanic and filler effect of RHA. Ramezanianpour et al. [14] also reported an increase in tensile strength with use of RHA as a partial replacement for OPC. The spilt tensile strength of concrete incorporating RHA was found to increase up to 20% OPC replacement level. Fig. 2 shows the effect of the size of RHA particles on the


19

split tensile and flexural strength of concrete. It will be observed that there’s a reduction in the tensile strength with increasing replacement level of OPC with RHA. Foong et al. [15] and Le et al. [16] showed an increase in split tensile strength to 15% RHA. Khassaf et al. [17] also reported an increase in tensile strength to 10% RHA. Ganesan et al [18] observed an increase in split tensile strength up to 20% replacement of OPC with RHA. However, the split tensile strength at 30% was found to be similar to that of concrete without RHA [18] Water to cement ratio was also stated to play a significant role in the split tensile strength of concrete incorporating RHA as partial replacement of OPC [17].

3.3

Flexural strength

Flexural strength which can also be referred to as modulus of rupture is the ability of a concrete to resist deformation as a result of bending. Flexural strength of concrete with RHA as partial replacement of OPC was found to correlate to that of its split tensile strength. Talsania et al. [19] reported an increase in flexural strength to 20% OPC replacement level with RHA. However, another study by Vinothan and Baskar [20] showed an increase in flexural strength only to 10% replacement level of OPC with RHA. Khan et al. (2012) reported a lower flexural strength in concrete incorporating RHA as partial replacement of OPC. And with an increase in the percentage of RHA, the deflection at midspan of the concrete decreases (Khan et al., 2012). Zhang et al 2009) reported an enhancement in the flexural strength of concrete when RHA is used as partial replacement of OPC. This enhancement has been attributed to both pozzolanic and filler properties of RHA. Also, from Fig. 2, it can be concluded that the flexural strength of concrete increases with a decrease in RHA particle size.

Fig. 2. Effect of RHA particle size on tensile and flexural strength at 180 days (data from [11])

3.4

Modulus of elasticity

Modulus of elasticity of concrete indicates its ability to resist elastic deformations. Concrete incorporating RHA as a partial replacement for OPC

20

Adeyemi Adesina

have exhibited a higher modulus of elasticity (MOE) compared to those without RHA [14]. The MOE increases with increase in RHA replacement level and age as shown in Fig. 3. This was also in agreement with the study by Foong et al [15] where they observed an increase in MOE with an increase in replacement level of OPC with RHA. The increase in MOE with the incorporation of RHA as partial replacement of OPC as been ascribe to the RHA particles being able to fill the pores in the matrix effectively due to their fineness. Filling of the pores leads to more refinement of the interfacial transitional zone between the aggregate and the binder matrix.

Fig. 3. Effect of RHA replacement level and age on the modulus of elasticity (data from [14])

4.

Conclusion

Based on this overview, the following conclusion can be made about the use of RHA in concrete. • Replacement of OPC with RHA in concrete enhances both its early and late mechanical strength. However, a replacement level of 10% is suggested. Enhanced mechanical strength due to use of RHA as a partial replacement for OPC is as a result of its pozzolanic and filler effects. • Use of RHA in concrete creates an avenue to manage RHA in a sustainable and effective way. Also, a reduction in cost and carbon dioxide emission can be achieved, as OPC is the highest contributor to cost and carbon emission in concrete. In addition, high cement savings can be achieved through the use of RHA as a replacement for OPC. • A need for more research on other mechanical properties (i.e. shear and bending strength) is necessary to better understand the overall mechanical behaviour of concrete incorporating RHA as a replacement for OPC


21

REFERENCES [1]

James J, Rao M. Characterization of silica in rice husk ash. American Ceramic society Bulletin 1986;65: 1177–1180.

[2]

Cook D. Development of microstructure and other properties in rice husk ash— OPC systems. In: Proceedings the 9th Australasian Conference on the Mechanics of Structures and Materials. University of Sydney, Sydney, 1984: 355–60.

[3]

ASTM C618-17a, Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete, ASTM International, West Conshohocken, PA, 2017, www.astm.org

[4]

Chandrasekar S, Satyanarayana K, Raghavan P. Processing, Properties and Applications of Reactive Silica from Rice Husk — an Overview. Journal of Materials Science, 2003; 38: 3159

[5]

Muthadhi A, Anitha R, Kothandaraman S. Rice Husk Ash — Properties and its Uses: A Review. Department of Civil Engineering, Pondicherry Engineering College, Puducherry. I. E (I) Journal, 2007.

[6]

Maeda N, Wada I, Kawakami M, Ueda, T., et al. Development of a New Furnace for the Production of Rice Husk Ash. The Seventh CANMET / ACI International Conference on Fly ash, Silica Fume, Slag and Natural Pozzolans in Concrete. Vol. 2, 2001, Chennai, India.

[7]

Ikpong A, Okpala D. Strength characteristics of medium workability ordinary Portland cement-rice husk ash concrete. Building and Environment, 1992: 27 (1): 105–111

[8]

Zhang M, Malhotra V. High performance concrete incorporating rice-husk ash as supplementary cementing materials. ACI Mater J 1996; 93(6): 629–36.

[9]

Wada I, Kawano T, Mokotomaeda N. Strength properties of concrete incorporating highly reactive rice-husk ash. Transaction of Japan Concrete Institute, 1999; 21 (1): 57–62.

[10]

De Sensale G. Strength development of concrete with rice-husk ash. Cement & Concrete Composites, 2006; 28: 158–160

[11]

Habeeb G, and Mahmud H. Study on Properties of Rice Husk Ash and Its Use as Cement Replacement Material. Materials Research, 2010; 13(2): 185-190.

[12]

Kartini K. Effects of Silica in Rice Husk Ash (RHA) in producing High Strength Concrete, Journal of Engineering and Research 2012; 26: 1951–1956.

[13]

Ismail M, Waliuddin A. Effect of rice husk ash on high strength concrete. Construction and Building Materials (Guildford), 1996; 10(7): 521-526.

[14]

Ramezanianpour A, Mahdi khani M, Ahmadibeni G. The Effect of Rice Husk Ash on Mechanical Properties and Durability of Sustainable Concretes International Journal of Civil Engineering, 2009; 2: 83 – 91

[15]

Foong K, Alengaram U, Jumaat M. et al. Enhancement of the mechanical properties of lightweight oil palm shell concrete using rice husk ash and

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Adeyemi Adesina manufactured sand. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering, 2015; 16 (1): 59–69.

[16]

Le H, Muller M, Siewert K, et al. The mix design for self-compacting highperformance concrete containing various mineral admixtures. Mater. Des. 2015; 72: 51–62.

[17]

Khassaf S, Jasim A, Mahdi F. Investigation the properties of concrete containing rice husk ash to reduction the seepage in canals. Int. J. Sci. Technol. Res. 2014; 3 (4): 348–354.

[18]

Ganesan K, Rajagopal K, Thangavel K. Rice husk ash blended cement: assessment of optimal level of replacement for strength and permeability properties of concrete. Construct Build Mater 2008; 22: 1675–83.

[19]

Talsania S, Pitroda J, Vyas C. Effect of rice husk ash on properties of pervious concrete, International Journal of Advanced Engineering Research and Studies, 2015; 4: 296-299.

[20]

Vinothan K, Baskar G. Study of structural behaviour on pozzolanic material (Rice Husk). Int. J. Civ. Eng. Technol. 2015; 6 (9): 31– 46.

Adeyemi ADESINA Concordia University Building, Civil, and Environmental Engineering

OVERVIEW OF THE MECHANICAL PROPERTIES OF CONCRETE INCORPORATING WASTE FROM THE CONCRETE INDUSTRY AS AGGREGATE Keywords: green material; rice husk ash; sustainability; concrete

Abstract Millions of tons of construction and demolitions wastes (CDW) are generated annually by the concrete industry, and these wastes most times end up in landfills where they contaminate the environment. As the global demand for concrete increases with a consequential increase in the consumptions of its components, the use of alternative materials as components in concrete will create a pathway to meet the future demand for concrete. One of the sustainable way forward is replacing the most voluminous component of concrete (i.e. aggregates) with CDW. However, in order to use CDW as aggregate, it needs to undergo processing which turns it into recycled aggregate. Mechanical properties of concrete are greatly affected by the components in concrete, and the replacement of natural aggregates with processed CDW is expected to alter the resulting properties of concrete. Though there are several contradicting conclusions in the literature which might be as a result of different sources and properties of CDW (i.e. recycled aggregate) used. This overview showed that processed CDW can be used successfully as aggregate in concrete to achieve similar/higher strength compared to those made with natural aggregate. But the proper treatment of the recycled aggregate and/or additions such as incorporation of supplementary cementitious materials have to be made. Also, the use of alternate binders such as alkali-activated materials with recycled aggregate can be used to achieve enhanced mechanical properties. In conclusion, the use of these wastes as aggregates in concrete will help to prevent more exploitation of natural deposits of aggregates alongside with reducing the overall cost of the concrete.

Abbreviations AAM – alkali-activated materials AAS – alkali-activated slag AASC – alkali-activated slag concrete FA – fly ash ITZ – interfacial transition zone MA – mineral admixture MK – metakaolin NA – natural aggregates NAC – natural aggregate co concrete

NM – normal mixing OPC – ordinary Portland cement OPCC – ordinary Portland cement concrete RA- recycled aggregate RAC – recycled aggregate concrete SCM – supplementary cementitious materials SF – silica fume SL - Slag TSM – two-stage mixing

24

Adeyemi Adesina

1. Introduction The use of concrete as a building material is increasing as time passes by, and more increase in its use is expected in the coming years due to rapid infrastructure developments going on globally. The increasing use of concrete as a preferred building material is due to its versatility, durability and strength. Concrete is mostly made up of the binder, aggregates and water. The high production of concrete has led to a consequential increase in the consumption of these materials (i.e. binder, aggregates and water). And about 20 million tons of materials have been reported to be consumed annually to make concrete [1]. Also, the concrete industry has been ascribed as the highest consumer of natural resources. With the high demand for concrete foreseen for coming years, it is paramount to find alternatives to the current components used in concrete, as most of these components are sourced or processed from natural resources. An important component to find an alternative for is the aggregates used in concrete's production as they make up about 60 – 75% of the volume of concrete [2]. Natural aggregates (NA) used in concrete are generally classified based on size and mostly sourced from natural deposits such as rocks and river beds. And with billions of volumes of concretes already produced, these natural deposits of aggregated have been overexploited, and continuous exploration of aggregates from these sources will lead to a detrimental disruption and damage to the ecosystem. On the other hand, millions of tons of wastes are generated from the concrete industry annually. For example, about 50% of the solid waste generated in the United States is from the construction industry [3]. These wastes are from demolition and construction of infrastructures. Most of these wastes end up in landfills where they occupy a large volume of space and pose a threat of contamination to the environment. The incorporation of CDW in new concrete will be a sustainable alternative to manage these wastes effectively while meeting the demand for concrete. However, there is a need to process these CDW into recycled aggregates (RA). From open literature, the strength of concrete incorporating CDW as RA has been generally accepted to be lower than that made with NA. And more reduction in strength reported with increasing replacement level of NA with RA [4-6]. This generalized observed reduction in strength has also made RILEM TC 121 DRG [7] to limit the NA replacement level with RA to 20%. The lower mechanical properties of concrete with the use of RA has been associated with the existence of hardened mortar adhered to the processed RA [8-9]. The adhered mortar on the processed RA is porous which makes it undergoes cracking easily when subjected to various types of loads [10]. Also, the adhered hardened mortar creates a weak zone due to numerous pores in its interfacial transition zone (ITZ) with the aggregate [10]. To simplify the classification of concrete made with different types of aggregates (i.e. NA and RA), the concrete

Overview of the mechanical properties of concrete incorporating waste from …

25

made with RA independent of the NA replacement level with RA are classified as recycle aggregate concrete (RAC). And corresponding concrete made with NA as natural aggregate concrete (NAC). The mechanical property of concrete is one of the major factors they play a role in its structural application. Therefore, in order to have more understanding on how RA can be incorporated successfully in concrete without sacrificing its strength aspect, this paper gives an overview of the major mechanical properties of concrete incorporating processed CDW as aggregates. The compressive strength alongside other mechanical properties are explored. It is hoped that this overview will create more awareness about the sustainable use of CDW in concrete and will encourage more research and development in the finding alternative building materials. In addition, this paper will serve as a reference for researchers and engineers looking to find ways in which the construction industry can meet the future demand of concrete while conserving the environment.

2. Construction and demolition waste (CDW) CDW makes up the largest component of solid waste in different countries, and are generated during new construction, renovation of existing infrastructures or as a result of demolition resulting from natural and human disasters. CDW is made up of various materials such as concrete, metal, wood, glass, etc. Tam et al. [10]. However, recycled concrete is the main material in these wastes used as aggregate in concrete. Recycled concrete possesses adhered mortar which is mainly associated with its low performance. When CDW is processed to be used as aggregate in concrete, the resulting product can be classified as recycled aggregate.

2.1.Need for incorporation of CDW as aggregate in concrete Use of processed CDW as aggregate is advantageous in the long run due to the following main reasons; 1) Source of aggregates: At the current rate of increase in population and development in the world, the current natural reserves of aggregate might not be able to meet the current and future annual demand of aggregate for concrete’s production. Therefore, the use of processed CDW as aggregate in concrete will help complement the supply from the natural reserves 2) Sustainability: The mining and/or sourcing of some natural aggregates are highly energy intensive and emit carbon dioxide to the environment. In addition, the exploration of aggregates from these natural deposits has created several deformations in the ecosystem. Therefore, incorporating processed CDW wastes into concrete will lead to the reduction/ elimination of energy consumed and carbon dioxide emitted to the environment during its processing. However, it is essential to

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mention that the processing of some of the CDW are energy intensive, but it is negligible due to it being a waste. 3) Cost: Aggregates are the most voluminous component of concrete, and high cost is associated with their procurement. As CDW are classified as waste (i.e. no value), there use as aggregate in concrete led to a reduction in the cost of the concrete 4) Waste management: As mentioned earlier, CDW are mostly deposited in the environment where they occupy space and contaminate it. Therefore, their utilization in concrete creates an avenue to effectively manage them while conservation space and the environment in the process

3. Mechanical properties The incorporation of any material into concrete affects its properties, and one of the important properties that are critical for civil engineering applications are the mechanical properties. As the properties of concrete made with processed CDW (i.e. RA) differs from that of NA, it is expected that the resulting mechanical properties of concrete made from these two types of aggregate will differ. The effect of incorporation of RA on the main mechanical properties (i.e. compressive, flexural and tensile) of concrete are further elaborated.

3.1.Compressive strength The compressive strength of concrete indicates its ability to withstand the load in compression and can be related to other types of concrete's mechanical properties. Though the compressive strength of concrete is mainly controlled by the water to binder ratio, other components such as aggregate also play a significant role. The compressive strength of RAC has been reported to be lower than that of NAC [11-13]. This reduced strength has been attributed to the existence of double interfacial transition zone (ITZ) in the matrix as a result of the adhered mortar on RA [10]. The presence of adhered mortar on the RA also leads to higher porosity of the matrix [14]. In addition, the higher water absorption by the RA leads to the supply of an inadequate amount of moisture for the hydration reaction which results in a lower strength of the RAC. Several other studies also agreed with the reduction in compressive strength with the use of RA in concrete. A decrease in compressive strength was reported when crushed clay brick (CCB) was used up to 50% as a partial replacement of NA [12]. Reduction in compressive strength of RAC with the use of CCB as coarse RA was also reported by Aliabdo et al [13]. However, in another comprehensive test carried out by de Brito et al [15], they concluded that the incorporation of RA into concrete does not affect its strength. The study showed that that RAC made with 100% RA and 25%RA gave similar results which are identical to that of the control. Also, when 1% superplasticizer by mass of the binder was used for the RAC with 100% RA; a higher strength greater than that of the control


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was recorded as presented in Fig. 1. Several initiatives to enhance the compressive strength of RAC has been reported such as partial replacement of OPC with recycled glass [16], metakaolin [17], use of mineral admixtures [18]. The use of two-stage mixing (TSM) created by Tam et al. [10] has also been found to densify the RAC matrix thereby enhancing its strength [19]. As shown in Fig. 2, mineral admixtures (MA) improve the compressive strength of the concrete made with 100% RA. Enhanced mechanical strength with the use of MA has been attributed to its pozzolanic and pore filling properties. And the use of silica fume to enhance the strength of the RAC exhibited higher strength compared to those enhanced with fly ash. This higher enhancement of silica fume can be attributed to its smaller size which increases the rate of reaction. The silica fume was also reported to improve the early strength of the RAC [18]. Similar to NAC, the strength of RAC increases with a decrease in water to binder ratio [20].

Fig. 1. Effect of incorporation of RA on the compressive strength of concrete at 28 days (Data from [15]) Etxeberria et al [21] found that the strength of RAC increases with a decrease in water absorption of RA. And that RA obtained from higher strength concrete waste show higher strength of RAC compared to RA processed from the waste concrete of low strength [21]. However, Kou et al [22] reported a contradicting result has there was no significant difference in the compressive strength of RAC made with RA from original low and high strength concrete Also, Elhakam et al [23] reported that good grading of RA might lead to higher compressive strength of the RAC.

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Fig. 2. Effect of mineral admixtures on 28 days compressive strength ([18]) RA made from concrete wastes from precast plants have been found to give better compressive strength compared to other sources [24]. This might be as a result of the higher strength of original concrete produced and controlled construction processes. However, the strength recorded for RAC made with RA from the precast plant is still lower than that of NAC [24]. The higher compressive strength of RAC made with 100% RA was observed when basalt fibre was incorporated at 2% [25]. Increasing the cement content has also been reported to enhance the strength of RAC [21]. Similar to NAC, the compressive strength of RAC has been found to be affected by the curing regime employed. The use of carbon dioxide to cure RAC has been reported to yield enhanced early strength [26]. About 4 – 15% increase has been observed when stream curing was used for RAC [27]. Saravanakumar et al. [28] also tried different treatment methods to enhance the properties of RA by pre-soaking them in different acids. It was observed that a little compressive enhancement was achieved with the pretreatment methods as shown in Fig. 3. However, the improved compressive strengths were lower to that of the control concrete with no RA.


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Fig. 3. Effect of different RA treatment on 28 days compressive strength (data from [28]) Alkali-activated materials (AAMs) are gaining huge attention in the concrete industry due to its possibility to replace OPC in conventional concrete. And AAM such as alkali-activated slag (AAM) has been found to be eco-friendlier as no heat curing is required compared to their geopolymer counterparts. In an attempt to see the effect of incorporation RA into AAS concrete (AASC), it was found out that the compressive strength development pattern of AASC was totally different from that of OPC concrete (OPCC). In fact, the compressive strength of the AASC incorporating RA increases until a replacement level of 50% [29]. And at all replacement levels, the strength obtained for AASC is greater than that of OPCC which also incorporates RA as shown in Fig. 4. The improved strength of AASC incorporating RA at all levels compared to similar OPCC has been attributed to the effect of the alkali activation and the filling effect of slag on the RA [29].

3.2.Flexural strength Flexural strength of concrete shows the ability of a concrete to resist deformation when subjected to bending. The flexural strength of concrete decreases with the incorporation of RA as an aggregate and the trend in strength reduction continues with an increase in the amount RA used [30,31]. Replacement of 20% NA with CCB as RA has been found to give optimum flexural strength as it yields similar flexural strength as that of the control with no RA [12]. However, a study by Arezoumandi et al [32] showed that RAC exhibited similar flexural strength compared to NAC. Use of recycled glass as a partial replacement of OPC or sand has been reported to enhance the flexural strength of RAC [33]. An optimum level of recycled glass for the replacement

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of OPC or sand has been ascribed to be at 10% [33, 34]. However, another study reported the use of 20% recycled glass to enhance the flexural strength of RAC [16]. Despite the enhancement of the compressive strength of RAC made with 100% RA at the addition of basalt fibres at 2%, there's no corresponding increase in the flexural strength of the RAC [25]. However, the use of glass fibre has been found to improve the flexural strength of RAC [35]. Using the two-stage mixing method developed by Tam et al. [10] has also been reported to improve the flexural strength of RAC. Use of AASC has been reported by various studies to have higher mechanical properties compared to that of AAS. This is not an exception when RA is incorporated into AASC. The higher flexural strength of AASC compared to that of OPCC was reported at all replacement levels of NA with RA as shown in Fig. 4.

Fig. 4. Strength properties of AASC incorporating processed CDW as an aggregate (data from [29]

3.3.Split Tensile strength The tensile strength of concrete is mostly assessed using an indirect testing method called split tensile test. Similar to RAC’s compressive strength, the split tensile strength has been reported to decrease with increase in NA replacement level with RA [22, 23, 36]. A reduction of over 20% in split tensile strength has been reported when 100% RA is used to make concrete [11]. The incorporation of glass fibre into RAC can be used to enhance the split tensile strength of RAC [35]. An increase above 10% was observed when glass fibre was used for different grade of RAC. Also, the use of nano-silica to densify the ITZ has been shown to enhance the tensile strength of RAC [37].


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Fig. 5. 28 day Split tensile strength of different RAC mixtures enhanced with mineral admixtures (Redrawn from [22]) Using mineral admixture as partial replacement of OPC in RAC has been shown to improve its tensile strength. Hasan et al. [17] reported that the use of metakaolin as partial replacement of OPC can be used to improve the split tensile strength of RAC. Though a decrease in compressive strength of RAC was observed when metakaolin was used at 20% replacement of OPC, there was an increase in split tensile strength of the RAC at the same metakaolin level-up to 40% use of RA in concrete [38]. Improved split tensile strength was also recorded when slag cement was used to produce RAC [39]. However, fly ash and slag gave a contradicting result as their incorporation in RAC led to a decrease in its tensile strength compared to the control as shown in Fig. 5 [22]. Similar to improved compressive strength with the use of AAS as a binder for RAC, the split tensile strength of AASC was reported to be higher than control at all replacement levels [29]. However, the maximum split tensile reported was at a replacement level of 50% and 75%, with a maximum difference of 0.5MPa with those made with 0%, 25% and 100% replacement of NA with RA as presented in Fig. 4. Parthiban and Saravana [29] concluded that the incorporation of RA into AASC does not have a significant effect on the split tensile strength of the AASC. Similar conclusions were also made for OPCC by Sageo-Crentsil et al [39], and Poon and Lam [40].

Conclusions and Recommendations Continuous global development will lead to more constructions and more CDW generated. Therefore, to create an avenue to meet the future global demand for aggregates for concrete construction while conserving our environment, it is essential to incorporate processed CDW as aggregates into concrete. However, the difference in properties of recycled aggregate and natural aggregate means their resulting properties will be different. Therefore, it is essential that when processed CDW is used as RA in concrete, it should be used in such a way it

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can maintain high mechanical integrity for various structural and non-structural applications. Based on this overview, the following conclusions and recommendations can be made 1) Use of RA in concrete not only lead to meeting the demand of aggregates for concrete but also prevents possible contamination of the environment that might have resulted from its improper disposal into the environment. 2) Use of RA in concrete will lead to a decrease in its mechanical properties. However, the use of mineral admixtures and superplasticizers can be employed to improve the strength of RAC to achieve similar/higher strength compared to that of NAC 3) Reduction in mechanical properties due to the incorporation of RA is due to the presence of pores and microcracks in adhered hardened mortar on RA which results in weak ITZ. Also, the lower strength and hardness of RA compared to NA play a role in the strength reduction. 4) The incorporation of processed CDW as aggregate alongside other sustainable initiatives such as partial to total replacement of OPC with SCMs will lead to enhancing mechanical strength and a significant reduction in the embodied carbon and cost of concrete. In addition, the combined use of these waste materials in concrete will ensure that the future demand for concrete is met while effectively managing different industrial wastes 5) With several contradicting results present in the open literature; more research and development in the utilization of different types of processed CDW as RA is needed especially in terms of enhancing its mechanical properties, so as to encourage its large-scale applications.

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Ali Reza AFSHARI Department of Industrial Engineering, Shirvan Branch, Islamic Azad University, Shirvan, Iran

REVIEW ON CONSTRUCTION PROJECT MANAGER SELECTION CRITERIA AND METHODS Keywords: Construction; Decision making; multiple criteria decision making; Project manager selection

Abstract The success of a construction project depends on several critical success factors. One important factor is supervision by a competent project manager with proven leadership skills. Therefore, the selection of a project manager for construction projects is, by nature, one of the most important and, at the same time, most complicated decisions to be made. Selecting the best project manager among many candidates is a multi-criteria decision making (MCDM) problem. Choosing a project manager for a construction project is a critical project decision. The scope of this paper deals with the decision making process concerning selection of the finalists for position of construction project manager. This article reviewed the corresponding methods in different stages of multi criteria decision making for construction project manager selection. Also, it provides an overview on various criteria used. This paper provides useful insights into the MCDM methods for construction project manager selection and suggests a framework for future attempts in this area for academic researchers and practitioners.

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Introduction Leadership studies in the construction industry, with few exceptions, concentrate on investigating the motivational factors and the personal characteristics of project managers (PMs). In recent years, the number of construction projects has been growing rapidly. Therefore, it is very important to find the right project managers for such projects (Zavadskas et al., 2008a). The role of construction project manager is very important in the process of construction. Recruiting the right project manager is an important challenge for organizations. The project manager is the person responsible for accomplishing project objectives. The project manager manages the project through identifying project requirements; establishing clear and achievable objectives; balancing the competing demands for quality, scope, time and cost; adapting plans and approaches to the different concerns and expectations of the various stakeholders; and managing projects in response to uncertainty. It is widely acknowledged that the final outcome of the project depends mainly on the project manager; therefore, the selection of the project manager is one of the two or three most important decisions concerning the project (Ahsan et al., 2013). As part of human resource management policies and practices, construction firms need to define competency requirements for project staff, and recruit the necessary team for completion of project assignments (Shahhosseini and Sebt, 2011). Traditionally, potential candidates are interviewed and the most qualified are selected. Precise computing models, which could take various candidate competencies into consideration and then pinpoint the most qualified person with a high degree of accuracy, would be beneficial. There are two main phases for establishing personnel selection models: developing the decision making hierarchy and selecting the methodology to be used. The former employee selection problem studies have developed decision making criteria based on job analysis. In addition, competency criteria hierarchies that have been studied in literatures are for general employees, and personnel of construction companies are not investigated in specific (Gilan et al., 2012). Multi-Criteria Decision Making (MCDM) methods have received much attention from researchers and practitioners in evaluating, assessing and ranking alternatives across diverse industries. In recent years, many studies have examined the application of MCDM modeling methods in decision-making processes, particularly in the construction industry (Torfi and Rashidi, 2011).decision making using multi-criteria decision making (MCDM) just provides a method to eliminate the difficulty and it has attracted the attention of decision makers for a long time. It is an operational evaluation and decision support approach that is suitable for addressing complex problems featuring high uncertainty, conflicting objectives, different forms of data and information, multi interests and perspectives.

Review on construction project manager selection criteria and methods

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This literature review was undertaken to identify articles in high ranking journals that provide the most valuable information to researchers and practitioners studying live issues concerning the project manager selection method. With this scope in mind, we conducted an extensive search for “Construction project manager selection” in the title, abstract, and keywords of scholarly papers. The key words or combinations thereof used to search for relevant literature included: competency; project manager; project management; construction industry; skill. We particularly targeted library databases: Elsevier, Springer, Taylor and Francis, Emerald, John Wiley, IEEExplore and EBSCO, covering major journals in operation research and management sciences.

Developing project manager competency As part of project HRM policies and practices, construction firms need to define competencies requirement for all project personnel and obtaining the team necessary to complete project assignments (Gilan et al., 2012). Competency is the knowledge, skills, and behaviors a person needs to fulfill his or her role. Construction projects tend to be characterised by crisis, uncertainty and suspense, which combine to test the ability and performance of the manager. Project success is, therefore, dependent upon the leadership qualities of project managers and their ability to bring the best out in their team (Dainty et al., 2005). The success of a construction project depends on several factors, one of which is the competencies of project managers. Their personalities, characteristics, skills and leadership styles also impact on project outcomes; with the latter being essential for construction projects. Project managers must be able to handle unanticipated problems competently (Ogunlana, 2008). There is a growing awareness of the relationship between achieving project success and construction project managers’ competences. Realizing the significance of modeling PM competency has led to substantial interest from academics and industry practitioners seeking vital qualities of exceptional PMs (Zhang et al., 2013). Although there have been numerous frameworks to evaluate PMs, literature reveals that computing the relative importance of PM competencies has been based on subjective rather than data-driven techniques. The recent studies have attempted to centralize the competency concept and focused more on classifying the competencies according to the different natures of projects. Crawford (2005) provided further insight towards enabling a more in-depth understanding of the potential dimensions of the term competency by proposing three interesting classifications, namely input competencies, personal competencies, and output competencies. Input competencies as defined by Crawford refer to the knowledge and skills that a person brings to a job. Personal competencies are the core attributes underlying a person’s capability to execute a job. Output competencies relate to the demonstrable performance that a person exhibits at the job place. Suikki et al. (2006) emphasized the

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administrative, leadership, and business skills of project managers. Wu and Lee (2007) combined fuzzy logic and decision making trial and evaluation laboratory (DEMATEL) to segment required competencies for better promoting the competency development of global managers. Ahadzie et al. (2008) studied the construction projects and developed competency-based measures for evaluating the project managers in mass house building projects. Patanakul and Milosevic (2008) studied the multi-project environments and proposed a list of competencies that multiple-project managers should possess. Liu et al. (2010) examined the relationship between competency and success in the information systems project environment. They modeled the link between general task completion competency and performance of development teams with two crucial antecedents built by other stakeholders, the contribution of users and controls established by management. Müller and Turner (2010) focused on the leadership competency profiles of successful project managers in different types of projects. They prepared a Leadership Development Questionnaire (LDQ) and sent it to various experts and received 400 responses. The obtained results were used to profile the intellectual, managerial, and emotional competencies for project managers. Shahhosseini and Sebt (2011) proposed a competency-based model for the selection and assignment of construction project personnel, which are classified into four types: Project Manager, Engineer, Technician, and Laborer. By consideration of main personnel competency, they developed a twostage model representing complete project staff evaluations. The model was trained with a number of actual data taken with a series of interviews. During the early 2000s, many researchers heavily investigated and attempted to define the term competency with regard to job assessment (Hanna Awad et al., 2016). Chen and Partington (2006) used a phenomeno graphic research approach to determine that CPMs conceived construction project management as: planning and controlling, organizing and coordinating, and predicting and managing potential problems. These concepts were converted into key competencies that CPMs needed to accomplish construction activities. For instance, four abilities are needed to understand planning and control; these include the ability to plan, having adequate knowledge of construction, the ability to communicate and the ability to manage a team. Mahmood et al. (2006) continued exploration into the field of PM competency by examining five related job competency models and devising a new job competency model for PMs. Their model consists of 198 job competencies, concluding that different professions require a different mix of core competencies. In the same year, Shao (2006) developed a PM quantitative selection methodology using 102 competencies identified by the Project Management Institute (PMI). He used a web-based survey to ask 16 experts about their opinions regarding the relative importance (weights) of each of the competencies. Offering a new perspective, Patanakul et al. (2007) emphasized the significance of considering PM competencies while matching PMs to projects. During the same year, PMI


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updated its 2002 edition of the Project Manager Competency Development (PMCD) framework, outlining impactful competencies of their defined dimensions of project management: knowledge, performance, and personal. Ahadzie et al. (2008) argued that a contextual task model has empirical relevance for application in project-based sectors of the construction industry where the relative abilities of construction project manager were identified. Their study highlighted PMs' soft skills as more critical predictors of PMs' performance than hard skills. More recently, Ehsan et al. (2010) highlighted that exceptional PMs must possess particular uniqueness that enhances team performance based on competencies in nine different areas, including integration management, cost management, and quality management. Zhang et al. (2013) identified the key social competencies for Chinese construction project managers. Hanna et al. (2016) distinguish outstanding PMs from average ones and reflect on the relative importance that professionals in the construction industry attribute to each competence of a PM. By using an additive model in their research, they consider that a PM’s particular deficiency in a competence area could be compensated by another where this same PM has greater success. In this case, whatever important competencies for success that PMs have in a given project could be balanced by others that are less necessary.

Construction project manager selection problem A project is a temporary endeavor undertaken to create a unique product, service or result. Projects help organizations to earn desirable strategic changes in a changeable world. In other words, organizations use projects as a tool for achieving strategic objectives. Project managers are responsible for the leadership role in projects (Müller and Turner, 2010). Therefore, selecting a competent project manager which has the necessary skills for project leadership can be lead to improve the excellence level of project. Here, an important question is that what criteria or skills are needed for project managers to perform projects successfully (Sadeghi et al., 2014). In the last two decades, many researchers have been exploring the general skills that a project manager should possess, as well as those needed to succeed, and the criteria for the selection of project managers. In the 1990s, several researchers detailed skills of project managers and proposed several frameworks. Thamhain (1991) presented three categories of project managers’ skills, which are leadership, technical, and administrative, while Pettersen (1991) proposed five categories: problem solving, administration, supervision and team management, interpersonal relations, and some other personal qualities of project managers. Technical skills, conceptual skills and human skills are considered by Goodwin (1993), as the main four skills project managers cannot do without. According to Goodwin (1993), conceptual, technical, negotiation, and human resource skills are the four main

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skills that a project manager should possess. Berger (1996) highlighted the growing need for civil engineers with management skills and, perhaps, advanced degrees in engineering management. Perini listed the primary qualities of a successful construction project manager as follows: a high level of technical skill; diligence; and the ability to manage the executive team, communicate effectively, pay attention to the client’s demands, prioritize, perform under pressure, ask the right questions, and take responsibility and the necessary risks to achieve goals (Liao, 2007). Collins (1998) takes a holistic view on the project manager candidates, which also includes the addition of any selection criterion deemed relevant to a specific project. The results are scored and, in case of a close score between candidates, the candidates’ availability could help swing the decision. While this has some merit, it must be noted that using the criteria in the table could result in selecting a project manager for the wrong reasons. Collins (1998) states: “The process focuses on the premise that a successful project manager must master two primary skill sets: the project manager’s technical skills and leadership skills.” Meredith et al. (2011) classified the skills required by a project manager into six distinct groups: communication, organizational, teambuilding, leadership, coping, and technological. Ogunlana et al. (2002) believed that conceptual, human resource, negotiation, and technical skills are the most essential skills for a project manager. Sunindijo et al. (2007) studied emotional intelligence (EI) in the context of project manager selection. The results of these studies revealed that EI is beneficial to both the individual and the organization. Pheng and Chuan (2006) identified the factors that effectively influence the performance of a project manager in the private and public sectors. Dolfi and Andrews (2007) studied the personality characteristics of project manager and formulated a conclusive understanding of the motivations of project managers, especially concerning their work environment. A large number of studies have been conducted on the characteristics and responsibilities of project managers; however, only a few of them deal with the selection of project managers. The traditional method for selecting a project manager for a construction firm is to choose the best candidate after interviewing the potential ones. The interview is usually conducted by the construction firm’s top managers (Jazebi and Rashidi, 2013).

Table 1. Construction project manager selection review Citation (Baykasoglu et al., 2007) (Zhao et al., 2008) (Zavadskas et al., 2008b)

Application Project team members Selection Engineering Project Manager Selection

Method Fuzzy multiple objective optimization model

Construction Project manager selection

Grey relational analysis

3ULQFLSDOFRPSRQHQW DQDO\VLV3&$

Review on construction project manager selection criteria and methods Citation (Zavadskas et al., 2008a)

Application Construction Project manager selection

(Zhao et al., 2009)

Selection of a Project Manager Construction Project manager selection Construction Project manager selection Selection construction project manager

(Xing and Zhang, 2006) (Rashidi et al., 2011) (Shahhosseini and Sebt, 2011)

Method Complex Proportional Assessment of alternatives with Grey relations (COPRAS-G) Fuzzy Comprehensive Evaluation Fuzzy Analytical Hierarchy Process Neurofuzzy Genetic System Fuzzy AHP; Adaptive NeuroFuzzy Inference System (ANFIS)

(Gilan et al., 2012)

Project manager selection

Computing with words

(Afshari et al., 2012)


Fuzzy Simple Additive Weighting method

(Zavadskas et al., 2012)

43

$+3$5$6

(Afshari et al., 2013) (Torfi and Rashidi, 2011)

Project manager selection Selection of Project Managers in Construction Firms

Fuzzy Integral

(Hadad et al., 2013)


Data Envelopment Analysis

(Jazebi and Rashidi, 2013)

selecting project managers in construction firms

Fuzzy curves method

(Varajão and Cruz-Cunha, 2013)


$+3,&%

(Sadeghi et al., 2014)

Evaluating Project Managers

TOPSIS technique

(Mohammadi et al., 2014)


Cybernetic ANP, QFD

(Keren et al., 2014) (Dodangeh et al., 2014)

Selecting a Project Manager Selecting a Project Manager

AHP and DEA Methods

(Reza Afshari, 2015)

Selection of construction project manager

Delphi and fuzzy linguistic

(Chaghooshi et al., 2015)


(Cassar and Martin, 2016)

Choose a Project Manager

Fuzzy DEMATEL, Fuzzy VIKOR CLOUD theory

(Sadatrasool et al., 2016)


AHP and Fuzzy TOPSIS

Fuzzy MCDM

VIKOR and PCA-TOPSIS method

Source: own research

Conclusions and directions for further research Some of the gaps existing in the literature addressed by this study: - First, no previous work provides a systematic model for criteria selection in construction project manager selection problem, and further study need to remedy this situation by providing a systematic method for eliciting criteria from panel of experts.

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Ali Reza Afshari

-

-

-

-

-

Second, the usage of fuzzy linguistic variables to conduct evaluation will finally enhance the efficiency of decision making by reducing error in utility values. Finally, group decision making (GDM) is a very important factor for a comprehensive solving of the problem. But it has not been considered in the majority of the reviewed studies (Kelemenis, Ergazakis, & Askounis, 2011). The approach that considers one single decision maker (DM) is not sufficient in conducting a multi criteria decision making. One of the critical tasks for an organization is project manager selection; therefore, more rational decisions are made by a group of people rather than by a single person. Although some researchers have utilized Neuro-fuzzy systems in construction research area (Jazebi and Rashidi, 2013), application of Neuro-fuzzy systems in this research field is still rare. It is suggested that researchers provide another effective mechanisms in modeling decision maker’s preferences and to effectively handle the imprecision of the human decision making processes in construction project manager selection problem. Therefore, further studies must be conducted to deepen how to identify the competencies that construction managers need, keeping in mind the fact those new classes of managers may be required for different projects.

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Rıfat AKBIYIKLI1 S.Ümit D KMEN2 Latif Onur U UR1 Ali ATE

1

1

2

Düzce University, Faculty of Technology, Department of Civil Engineering Bo aziçi University, Kandilli Observatory, Earthquake and Research Institute

FORSIGHT AND TRENDS IN CONSTRUCTION PROJECT MANAGEMENT Keywords: Construction, Foresight, Knowledge, Project Management, Trends

Abstract Construction is an industry that is very closely linked to the economy and society as a whole. As such, when developing an understanding of the future of the construction industry, it is important to understand the future of the economy and society as a whole. It is important for organizations within the construction industry and institutions for construction education to remain constantly aware and knowledgeable of the state of the future. The world is changing very fast. A wide range of trends and challenges have a direct bearing on the future of project management. It is very vital to understand those trends, so that the risks can be better managed for construction industry and make the most of emerging opportunities. Project-based work is characterised by high degrees of collaboration. Innovation and creativity are the key components of value creation. Employee expectations and working cultures are changing all the time. The main drivers affecting project management are across social, cultural, environmental, economical, legal, political and technological (SCLEEPT) domains. These domains have to be understood, evaluated and planned strategically for the future. These domains impacts on future work environments, professions and project management approaches. The complex and fragmented nature of the construction industry and the challenges ahead call for different approaches and different innovative tools to succeed in an unpredictable and changing environment. Future studies is to support long-term planning. The aim of this paper is to understand in what extend the topic foresight is being addressed in construction project management literature. It is actually an overview of the phenomena.

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Rıfat Akbıyıklı, S.Ümit Dikmen, Latif Onur U ur, Ali Ate

Introduction The management of construction projects requires knowledge of modern management as well as an understanding of the design and construction process. Construction projects have a specific set of objectives and constraints such as a required time frame for completion. A project organisation will generally be terminated when the mission is accomplished. Silva (2015) study covers a systematic review of foresight in project management literature. This study demonstrates that foresight research in project management literature is in its infancy and is characterised by a limited number of studies and a relative absence of theoretically informed research. It is concluded that future research is strongly needed. Foresight appears as an emergent practice and its use is worth considering in the context of project, programme and portfolio management. In their study Uchipte et al. (2016) stressed to formulate a means of predicting potential areas of research or emerging knowledge that could arise in the foreseeable future. Being able to predict the future for project management field is very encouraging since it is continuously growing and becoming vital in the construction industry. Coelho (2012) state that no project can succeed without an experienced project manager. Any project manager must be well-equipped with and utilise the right tools, appropriate to the project, in order to successfully guide a project to success. The proper information about the future direction of the construction industry will better prepare project managers to know which tools and techniques need to be learned and applied to resolve the unexpected and expected problems in the industry and its projects. The study of Uchipte et al. (2016) certainly indicates that there is a vast future for researchers and the industry in general. Rivera and Kashiwagi (2016) state that project management is the mechanism to delivering professional services and project managers are responsible for managing, directing and controlling projects. The main objectives of a project manager is to deliver a project on time, on budget and customer satisfaction. Besides a project manager must align all resources and ensure quality control on site work. There are always difficulties delivering services on time, on budget and with customer satisfaction. The literature identified that the industry has struggled with overcoming poor delivery of services, and has not seen any significant improvement in the last three decades, despite the increase in professional education and training (Egbu, et al. 2008; Goff, 2014). This is interesting, because not only will there be more projects in the next 30 years (CII, 2015), but projects have become larger and more difficult to manage due to the increasing number of participants, the increasing importance of legal contracts (Kashiwagi, 2013), and all the participants in the supply chain

Forsight and trends in construction project management

51

segmented in silos, resulting in an increased level of complexity. According to Construction Industry Institute study done in 2015, it successful in terms of scope, cost, schedule and business; 30 % of projects completed within 10 % of planned cost and schedule; 25 – 50 % waste in coordinating labour on a project; management inefficiency costs to owners between 15.6 and 36 billion US dollars/year; rework by contractors is estimated to add 2 – 20 % of expenses to a contractor’s bottom line and an estimated 4 billion US dollars to 12 billion US dollars is spent to resolve disputes and claims (Lepatner, 2007; PwC, 2009 and Yun, 2013). Rivera and Kashiwagi (2016) express their concern about the nonperformance of the overall construction industry and identified the following three potential solutions:

1. The lean management approach: This is known as a set of principles and techniques that assist organisations in eliminating wasted efforts and increasing likelihood to meet customer satisfaction. They argue that in this approach the owner’s management, direction and control is not minimised.

2. The agile project management approach: This breaks up a project into smaller components, utilises partnering between all stakeholders and lessons learned can be quickly implemented into the project’s other components. It is argued that the downside of this approach is that it does not minimise the owner’s management, direction and control (MDC), which is a source of project cost and time deviation.

3. The Best Value Performance Information Procurement System Methodology (BV PIPS): This is a non-traditional procurement/project/risk management model proposed by Dean Kashiwagi in 1991. It has been found to increase the efficiency of delivering services up to 40 % while simultaneously reducing project management up to 79 %. According to Rivera and Kashiwagi (2016) this is the most dominant solution based on the extensive performance documentation and impact in industry. They argue that, BV PIPS has the ability to minimise management, direction and control resulting in decreased costs on average 31 % and 98 % customer satisfaction. In this approach the role of project manager is shifted from being an expert to utilising expertise.

Construction Trends 1. Building Information Modelling (BIM): Building Information Modelling (BIM) as stated in Gorecki and Czaplewska (2017) is considered as the innovation that allows for the

52


consistent management of information in the construction projects. This tool is also useful in managing the process of building construction in the whole-life cycle perspective. BIM takes into account the most crucial thing in a construction project: Collaboration.

2. Real- time project management: Real-time project management is improving and optimizing the fundamental pillars of a construction project. Its contribution to the building process is critical. Real-time project management software empowers transparency, accountability and efficiency in construction.

3. Virtual Reality (VR) and Augmented Reality (AR): VR is able to provide virtual walk through in order to sell property and pitch architectural ideas to clients. In construction, it can be effectively used to provide safety training to workers. It enables easy communication on site. VR is more common in construction. AR’s basic essence is to enhance what we see through data and information. AR can provide accurate measurements, material details and reduce the risk of errors. (Example: DAQRI augmented reality technologies empower employees with next generation productivity – DAQRI Helmet). The era for virtual reality will come. Construction is becoming more data focused. It is expected more and better use of augmented reality (AR) in construction in future.

4. Drones: Data collected from drones can be used to analyse the progress of the project. The job, through drones, can be done faster and less costly. Usage of drones is expected to grow rapidly in future.

5. Sustainable and Green Construction: Green construction reduces waste and the use of resources. In future there will be more need for green construction. Green construction is going to force construction managers and constructor to change their business model.

6. Improved Labour: With improving technology there will be more intelligent labour in construction. Construction will need knowledge workers and people with skills to create, operate and maintain the advanced technology in construction.

Cloud – Based Project Management Mobile devices are revolutionizing the construction industry with cloud based project management providing real productivity improvements on jobsites. Both


53

cloud computing and mobile computing involve accessing the Internet with a device and using wireless systems to get to your files and data. According to a 2016 study from Associated General Contractors of America (AGCA, 2016) and Sage, 59% of construction firms surveyed had plans to use or already used cloud based project management software, leaving over 40% of companies virtually in the dark. A thorough understanding of how cloud technology enhances a construction project is critical to implementing the right software on the job. Cloud computing and mobile computing are two very different components, but when they are used together, they allow you to work or access the data you need from anywhere that has a working wireless connection. The easiest way to tell the two apart is by the role they play in communication: • Mobile computing includes the device you use to access the internet and could be a phone, tablet or laptop. • Cloud computing is the virtual storage space that holds your applications, files and data and allows you to securely access it when you need to. “Mobile computing” is a broad term that describes the different types of devices that allow you to access the Internet and your personal and work data, no matter where you are in the world. Mobile computing improves your connectivity, allows workers to perform tasks from home, from across town or even around the world with ease. Mobile computing also increases connectivity. “Cloud computing” actually refers to the storage space that holds your data, applications, images and more securely in place until you need to access them. One of the most valuable aspects of devices powered with cloud is the ability for you to switch devices and have the same information. As construction sites become more high-tech and the people managing them become increasingly connected, more industry professionals will likely shift toward implementing a cloud based strategy for data storage and sharing. That capability will allow project teams to streamline operations, giving each user the up-to-date data they need in real time—a process that, ultimately, will help compress any lag in information sharing and decrease the potential for error (Construction Dive, 2018) The enhanced collaboration provided by cloud based project management makes it easier and more efficient than ever for teams to work together.

Summary All managers have something they can continuously improve on. Just like the construction industry itself, construction management is evolving. Successful project managers will know how to adapt their skill set to meet the current need of the market and their employees. Furthermore, being an effective manager will

54


not only benefit your employees and your own job security, but it helps to ensure your projects run smoothly and effectively. Basic project managers have the qualifications and experience to manage the day to day of construction. Great managers have both the qualifications and expertise but know how to see the bigger picture and adapt. Most importantly, effective and adaptable project managers will be more adept to handle management of large-scale megaprojects.

REFERENCES [1]

Silva, M. (2015), A Systematic review of Foresight Project Management literature. Procedia Computer Science 64, pp.772-799.

[2]

Uchipte, M., Uddin, S. and Crawford, L. (2016), Predicting the future of project management research, Procedea – Social and Behavioural Sciences 226, pp. 27 – 34.

[3]

Coelho, L. S. (2012). Why Organizations Need Project Management. Retrieved from: http://blog.projectplace.com/whyorganizations-need-project-management/

[4]

Rivera, A. and Kashiwagi, J. (2016), Identifying the state of Project Management Profession, Procedia Engineering 145, pp. 1386 – 1393.

[5]

Egbu, C., Carey, B., Sullivan, K & Kashiwagi, D 2008, Identification of the Use and Impact of Performance Information Within the Construction Industry Rep, The International Council for Research and Innovation in Building and Construction, AZ.

[6]

Goff, S. (2014). “IPMA Education and Training Board Series: Closing the Gap between PM Training and PM Performance: Part 2: Closing the Gap.” PM World Journal, Vol 3(7).

[7]

CII. (2015). Performance Assessment 2015 Edition. Construction Industry Institute. Web. (2015). Retrieved from http://www. Constructioninstitute.org/performance.

[8]

Kashiwagi, J. (2013). Dissertation. “Factors of Success in Performance Information Procurement System / Performance Information Risk Management System.” Delft University, Netherlands.

[9]

Lepatner, B.B. (2007), Broken Buildings, Busted Budgets. The University of Chicago Press, Chicago.

[10]

PwC (PricewaterhouseCoopers), 2009, “Need to know: Delivering capital Project value in the downturn”. Retrieved from: Retrieved from https://www.pwc.com/co/es/energia-mineria-y-servicios-publicos/assets/need-toknow-eum-capital-projects.pdf.

[11]

Yun, S. (2013). The impact of the business-project interface on capital project performance. The University of Texas at Austin. Retrieved from http://repositories.lib.utexas.edu/handle/2152/22 804


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[12]

Gorecki, J. and Czaplewska, E. (2017), BIM for Cost Performance Optimization of Construction Processes, Civil Engineering Present Problems, Innovative Solutions – Optimization in Business and Engineering, CEPPIS Journal of Current Construction Issues, pp.67 – 82, Bydgoszcz, Poland.

[13]

(AGCA, 2016) The Associated General Contractors of America Retrieved from: https://www.agc.org/news/2016/01/06/seventy-one-percentconstruction-firms-plan-expand-headcount-2016-contractors-expect

[14]

Construction Dive (2018), Retrieved https://www.constructiondive.com/news/autodesk-to-cut-13-of-itspayroll/511890/

From:

Rifat AKBIYIKLI1 S. Ümit D KMEN2 David EATON3 1

Düzce University, Faculty of Technology, Department of Civil Engineering Bo aziçi University, Kandilli Observatory and Earthquake Research Institute 3 Madinah International Project Management and Investment Company, Turkey 2

RISK MANAGEMENT IN PRIVATE FINANCE INITIATIVE (PFI) ROAD PROJECTS: A ROAD CASE IN THE UK Keywords: PFI, Road Projects, Risk Management, Risk Transfer, SLEEPT

Abstract Construction is a complex and dynamic industry; and the main procurement parameters are time, cost, quality and certainty. A managed approach to risk is a means for providing the client with fewer surprises and greater certainty. Central to all PFI transactions are the contractual agreements put in place between the parties and these define each party’s roles making clear their expected requirements and liabilities. The contractual agreements define the apportionment of risk between the contractual parties. The incorporation of a risk register with identified risk owners as an addendum to the contracts clarifies the liabilities and responsibilities of the parties. The fundamental principle of a PFI project is that risks associated with the implementation and delivery of services should be allocated to the party that is best able to manage the risk. In a PFI concession, the Government’s view has been that it is reasonable to expect the project consortium (SPV) to take on systematic risk. Systematic risks can be classified as economic risk, legislative risk, taxation risk and financial arrangements. The financing arrangement risk crosses the boundary between construction and operation and may persist for the life of the contract and beyond; although there has been a tendency for re-financing early in the concession period. The Consortium Company (SPV) has separate contracts for the Construction Contractors and for the Operation and Maintenance Contractors and may have Services Contracts. The reason for this is to permit further transfer of risks to the party which has the ability to manage that risk. This paper will examine risk with the acronym so-called SLEEPT methodology, including social, legal, economic, environmental, political and technological aspects within the domain of a PFI road project in the UK.

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Rifat Akbıyıklı, S. Ümit Dikmen, David Eaton

Introduction According to Project Management Institute, PMI (2000, p.127) risk is “an uncertain event or condition that, if it occurs, has a positive or negative effect on a project”. Another definition given by APM (1997, p.169) states that, “risk is an uncertain event or set of circumstances that, should it occur, will have an effect on the achievement of the project’s objectives”. Chapman & Ward (2003, p.6) state that these definitions embrace both welcome upside and unwelcome downside effects. The above definitions of risk include a restricted and limited focus on events, conditions, or circumstances which cause effects on the achievement of project objectives. Therefore, uncertainty is a very important starting point for risk management purpose. In Chapman & Ward (2003) words, “uncertainty management is not just about managing perceived threats, opportunities, and their implications; it is about identifying that give rise and shape our perceptions of threads and opportunities. Key concerns are understanding where and why uncertainty is important in a given project context, and where it is not”. Risk is an uncertain effect on project performance rather than as a cause of an uncertain effect on project performance. Such a definition of project risk is, “the implications of uncertainty about the level of project performance achievable” (Chapman & Ward, 2003, p.12). Risk in construction projects is a complex phenomenon that has physical, monetary, cultural and social dimensions (Loosemore et al. 2006, p.1). As also indicated in Loosemore et al. (2006), construction projects demand a different management approach compared to other industries due to problems specific to the industry; the uniqueness of every project, difficulties in the forecasting the future in the industry and construction being a high-risk business. Those are inward looking issues for the industry and those characteristics do not merit special rules. As in all industries, in construction also a balance is needed between the avoidance of risks in one hand and risk seeking behaviour on the other. The challenge is always have to be the calculation, recognition and management of the risks effectively. Risks in PFI projects may also be caused by changes in relationships between the parties involved in supply, ownership, operation and maintenance of assets for public or private purposes. Risk management provides a structured way of assessing and dealing with future uncertainty. Project risk management applies across all project phases, and projects that arise at all phases of the asset life cycle. Project risk management refers to the culture, processes and structures that are directed towards the effective management of potential opportunities and adverse effects (Cooper et al. 2005 p.3). Risk management processes are designed to assist planners and managers in identifying risks and developing measures to address them and their consequences. This leads to more effective

Risk management in private finance initiative (pfi) road projects: a road case ...

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and efficient decisions, greater certainty about outcomes and reduced risk exposure (Cooper et al. 2005, p.4). In this paper, SLEEPT (Social, Legal, Environmental, Economic, Political, and Technological) will be utilised as a methodology for explicating potential risk issues in a road Project in the UK.

Risks and Risk Management and Private Finance Initiative (PFI) PFI is a way of achieving the maximum possible involvement of the private sector in the construction of public facilities and infrastructure. A PFI project is divided into a number of separate phases and at the end of each phase an appraisal can be made and an assessment of risk involved in proceeding with the project can be established. The management of risk is therefore a continuous process and should span all the phases of a project. According to Jackson (2004) a major feature of the PFI process is that risks are identified and costed. The key assumption is that the PFI process will act as a catalyst to ensure that risks are more effectively allocated between the public and the private sectors (HM Treasury Taskforce, 1997). It is of the utmost importance that the public sector should not automatically seek to transfer all risks to the private sector but the public sector should transfer a risk when it can obtain Value for Money (VFM) by such a risk transfer. There must always be an association between value for money and risk transfer in PFI deals. Value for money and risk management are the two key concepts of PFI. In relation to this association Illidge and Cicmil (2000) state that the intended complementary merger between the value for money objective and the idea of transferring project risk to the party best able to handle it has been an ideal solution to the persisting problem of escalating costs and uncertainty in public sector capital projects. The notion that PFI contracts transfer risk from the public sector to the private sector has been seen as one of the advantages of the use of PFI. Transferring risks to the private sector frees the taxpayer from unnecessary burden, creates a greater incentive for the private sector to deliver to budget and on time, and when they do, benefits the citizen the consumer of the services (Smith, 2001). PFI also enables the public sector to tap into the private sector management expertise. The accumulated knowledge gained by the experiential learning of the private partner is in managing risk transfer negotiation and project management which give a substantial advantage over the public sector. It allows the public sector to focus on core issues and to focus on strategic priorities and leave the operational management tasks to the private sector. The focus and primary aim of the public sector will be on end results and service standards. PFI is an innovation in public procurement but, the public sector must decide on the route which gives the best scope for the private sector to add value and in all cases adhere to key principles such as Whole-life Value for Money

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and Optimum Risk Allocation. Through such an attitude and approach it will be possible to deliver public services in an efficient, effective and innovative way. In a PFI concession, the Government’s view has been that it is reasonable to expect the project consortium (SPV) to take on systematic risk (Gallimore et al, 1997). Systematic risks can be classified as economic risk, legislative risk, taxation risk and financial arrangements (ibid). In this paper it will be utilised the SLEEPT (Social, Legal, Environmental, Economic, Political, and Technological) as a methodology for explicating potential risk issues. The financing arrangement risk crosses the boundary between construction and operation and may persist for the life of the contract and beyond; although there has been a tendency for re-financing early in the concession period. The Consortium Company (SPV) has separate contracts for the Construction Contractors and for the Operation and Maintenance Contractors and may have Services Contracts. The reason for this is to permit further transfer of risks to the party which has the ability to manage that risk. As stated above risk transfers are normally achieved by means of contracts. A thoroughly and correctly risk transferred PFI project has a greater chance to succeed to the satisfaction of the client and of the other parties in the concession and to be fit for its intended purpose. When the UK entered into the funding of public services through PFI procurement, risk was at the centre of the discussion. There was a strong expectation that Private Finance Initiatives would allow the public sector to deliver services without risk. This expectation is largely valid for the PFI projects in UK and the private sector is expected to ensure that complex and expensive projects are managed efficiently, delivered on time and to budget; and they will ensure that risk is managed effectively. PPP/PFI in a way is known as fast-track projects, where the normal project phases are compressed and the some extent overlap each other. Actually PPP/PFI projects take fast-track approach even further by shifting the assessment risk as well as that of detailed design and build risks to the front-end of the project. While the totality of this approach is perceived as being beneficial in shifting the bulk of the risk onto the private sector contractors, it has the detriment of reducing the step-by-step approach to management and decisionmaking which flows from the traditional multi-phase approach. Construction is a complex and dynamic industry; and the main procurement parameters are time, cost, quality and certainty. A managed approach to risk is a means for providing the client with fewer surprises and greater certainty. Central to all PFI transactions are the contractual agreements put in place between the parties and these define each party’s roles making clear their expected requirements and liabilities. The contractual agreements define the apportionment of risk between the contractual parties. The incorporation of a risk register with identified risk owners as an addendum to the contracts clarifies the liabilities and responsibilities of the parties.


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A fundamental principle of a PFI project is that risks associated with the implementation and delivery of services should be allocated to the party that is best able to manage the risk (HM Treasury, 1995). The risk categories will be borne by different contracting parties in any PFI project which is detailed below. A number of key areas of risk transfer noted in Fox and Tott (1999) are as follows:

1. Public Sector Risk Objectives: Transfer of design risk: The public sector specifies the service it requires and the project company is responsible for delivering the service. Payments to the private sector against performance and/or level of performance will be defined and graded by incentives to the private sector. Achieving high standards of performance will be rewarded and poor performance will be penalised; Transfer of planning risk: The private sector generally has wider experience in dealing with planning authorities than the public sector. Thus the public sector generally seeks to transfer this risk. Typically bankers will not be prepared to advance funds until detailed planning permission is obtained; Completion risk: This risk encompasses a number of separate aspects such as completion on time, completion to cost and completion to quality. This risk relates to the transfer to the private sector of the risk that facilities are completed and services become operational to time, to cost and to quality; Operational risk: The risk that facilities and services can be continuously provided, to the public authority throughout the contract term, to the agreed output specification, for the agreed unitary payment, will rest with the private sector. The payment mechanism will comprise an availability element or a performance element and a volume element; Residual value risk: Residual value risk is the risk that facilities associated with a service will continue to be required and will then have a value at the end of the contract term. In terms of PFI philosophy this risk should generally pass to the private sector as the public sector is merely buying a service for a given period and is not concerned with acquiring the assets associated with the service. But, in practice it is not like this. In the case of the road projects the ownership interest in the road is not transferred to the private sector however the SPV has an exclusive licence to construct and or operate during the concession period and accordingly full ownership will then revert to the public sector at the end of the concession period; Insolvency risk: The SPV in a PFI project is established with limited recourse to its consortium and will typically have no assets other than its interest in the project. Therefore the public sector’s objective will be to protect itself,

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both financially and in terms of ensuring the continuity of what are often vital public services, in the event of the insolvency of the private sector provider.

2. Special Purpose Vehicle’s (SPV) Risk Objectives: The SPV’s objectives in relation to risk transfer will be the opposite of the awarding authority and a compromise has to be found in the negotiation Project Agreement (PA). Once the risks accepted by the SPV are determined it will in turn, seek to pass them down to the construction subcontractors and operation and maintenance subcontractors and other third parties.

3. The Lender’s Risk Objectives: Most PFI projects have been financed on a limited recourse project finance basis. The most common way in which limited recourse has been achieved in PFI projects is by the private sector raising the finance being established as a Special Purpose Vehicle (SPV) which holds only the project assets and which conducts no business other than that contemplated by the Project Agreement (PA). The Lenders are granted security over all of the SPV’s assets as security for its obligations under the contract. The primary goal of the Lenders will be to ensure that the risks encountered at each stage of the project have been analysed and the liability for such risks allocated in such a way as to ensure that few if any risks remain with the SPV. The risks which the Lenders require managing are: Completion risk: Key areas are planning, design and construction. Until the project is fully operational no unitary payment is made to the project company from which to service the debt; Operation risk: This is the most important issue of PFI. Payment is only made against satisfactory compliance with the performance specifications; Pricing risk: The Lenders will require to be satisfied that the SPV’s cost estimates for operating costs and initial capital expenditure are realistic and make satisfactory allowances for contingencies; Revenue risk: The Lenders must ensure that the unitary payment is made as robust and as secure as possible by seeking to minimise and control the extent to which the under-performance of the SPV will result in non-compliance deductions; Public Sector (Awarding Authority) risk: Associated with the Lenders’ evaluation of the payment mechanism is the strength of the covenant of the public sector and whether it has the power to enter into the transaction and perform its obligations. In some instances the proposal mechanism may be Ultra Vires;


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Change of law risk: The effect of a change of law during the life of the project is a further matter for negotiation between parties. It is an important factor because PFI deals comprise a complex collection of individual contracts. Since the project organisations are subject to change of law and that it is common place to accept legislative risk in both the construction and operating phases of a PFI project, the Lenders are prepared to accept the change of law and the quantum of its effect; Sponsor/Contractor risk: A fundamental risk assessed by the Lenders is that of sponsor risk. A sponsor risk is associated with the financial, management and technical strengths of the sponsor, behind the PFI project. Given the limited recourse nature of most PFI financings, the funders will want to be satisfied that the SPV has the qualifications, experience, technical competence and sufficient financial resources available to enable it to perform its obligations under the Project Agreement (PA). For PFI schemes to succeed, two main issues are essential (Gallimore et al, 1997): 1. The private sector must take on risks which by definition have formerly been assumed by public sector occupiers; and 2. The price of this risk transfer must not be so expensive that it prevents satisfaction of the criterion of value for the public money expended in rewarding the risk. Gallimore et al. (1997) argue that there must be sufficient convergence of opinion on the level and degree of risk between the public sector purchaser and the private sector supplier to enable agreement on price to take place. The PFI process added novelty to an increase of risks which have been highlighted above to be borne by the three main parties of PFI. The payment mechanism in a PFI contract is the typical mechanism used to transfer the more common risks, to give the supplier an incentive to perform. The optimum risk transfer mechanism will vary widely from contract to contract and between different types of PFI service. The experience in the UK suggests that the public sector will seek to transfer design, development and operating risks in terms of both cost and performance. Demand and other risks have been most often a matter of negotiation between the service supplier and the service provider. The experience from executed PFI projects in the UK shows that the private sector is often considered to be best placed to manage the majority of risks regardless of whether this is strictly accurate. The private sector’s management of the majority of risks is always dependent on the fact that the public sector’s requirement is specified correctly. Risk management is not about predicting the future, but understanding a project and making a better decision regarding the management of that project tomorrow (Smith, 1999). Risk management is a structured approach to

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identifying, assessing and controlling risks that emerge during the course of the policy, programme or project lifecycle and its task is to ensure an organisation makes cost-effective use of a risk process that has a series of well-defined steps to support better decision–making through good understanding of the risks inherent in a proposal and their likely impact. (HM Treasury, the Green Book, 2003). The major feature of any PFI appraisal is that risks are identified and then quantified. Risk analysis is crucial for the following reasons: 1. to prove Value for Money; 2. to prove the robustness of the assumptions behind the choice of the PFI alternative; 3. to make explicit the affordability assumptions; 4. to determine which risks are to be retained by the public sector and which risks are to be transferred to the private sector. Some of the risks will be dependent on others and many of the probabilities, costs and outcomes will be uncertain. The concept of identification, analysis, mitigation, and control of the risks lies at the heart of the risk analysis and management of projects. Risk management, according to Eaton (2003) primarily has two important missions: 1. to identify the risks which comprises analysis of the likelihood of each risk event and determination of how serious the consequences might be; and 2. to identify the risk mitigation options where in each case there will be an inconvenience or cost factor and a decision will have to be made on whether mitigation is worthwhile. Depending on the quality of information and unless all the risks are mitigated, some residual risks will remain. Those residual risks are the ones which are not avoided, eliminated or transferred in the mitigation strategy. The author is of the opinion that risk management is a forward looking proactive process and primarily deals with risks before they become problems. It is essential that knowledge and information should be provided about predicted events in order to ease decision making in any PFI project. According to Liu, Flanagan and Li (2003) risk management can help to reduce, absorb and transfer risk and exploit potential opportunities. Mills (2001) suggests that risk management is an important part of the decision-making process of all construction activity. Eaton (2004 a and b) lists the aims of risk management as following: 1. Anticipate and influence events before they happen by taking a proactive approach; 2. Provide knowledge and information about predicted events;


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3. Inform and where possible improve the quality of decision making, recognising the preferred hierarchy of risk avoidance, risk reduction, risk control, and risk acceptance; 4. Avoid covert assumptions and false definition of risks; 5. Make the project management process overt and transparent, 6. Assist in the delivery of project objectives in terms of benchmarked quality, time and cost thresholds; 7. Allow the development of scenario planning in the event of the identification of a high impact risk; 8. Provide improved contingency planning; 9. Provide verifiable records of risk planning and risk control. The authors believe that the key to effective risk management is ownership. The Client should own any risks that affect the business or business case e.g. those that would prevent the benefits of the project from being fully realised; the Project Manager should own any risks that might affect the delivery of the project e.g. those that affect the project schedule and, the Project Contractor should own any risks that might affect the Contractors’ ability to deliver the project objectives. Furthermore we believe that risk management in PFI requires a ‘top-down’ approach; and key business risks should be identified, evaluated and managed. In a ‘top-down’ approach management should allocate time at the start to lay the foundations for the ongoing risk management process. Good risk management should have the potential to re-orient the whole PFI organisation (either public or private sector) around continuous performance improvement. The overall aim is to instil and subsequently continuously improve a risk culture at all levels of the respective organisations and in all phases of the PFI procurement process. Risk assessment focuses on how risks affect the objectives. The ultimate goal is the creation of an overall ‘big-picture’ of the uncertainty focusing on the public or private PFI organisations. To reach this ultimate goal the author believes in the creation of a culture of risk awareness in the organizations. Upon creation of such awareness the data is collected and risk models will be constructed. The risk assessment will be communicated transparently within the assigned participants, with roles and responsibilities for risk assessment stipulated. Risk assessment in order to be successful for the overall aim of the PFI procurement must be embedded into the management and planning process and not carried out in isolation.

Framework for Risk Management (RM) for PFI Road Projects This section critically examines and proposes a whole life cycle risk management framework for PFI road projects. This framework was conceptualised based on the empirical data collected. The risk framework took a risk register from the projects and through analysis

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identified and allocated the risk to those parties (different stakeholders) significantly affected by the occurrence of a particular risk in the road projects utilising the tool Multiple Estimating Using Risk Analysis (MERA). Risk management is central to a PFI project. It aims at identifying all the risks involved, to calculate the financial consequences, to establish mitigation procedures and to allocate the risks to be transferred to the party best able to manage them. Risk management is an interdisciplinary process where all stakeholders are involved. The risk model in this paper is limited to the project specific risks. The risks in this research are grouped as per risk ownership. The risks are owned as: (1) Granting Authority, (2) SPV and (3) Shared and tabulated in Table 1. The list of the risks shown in the Table 1 was provided by the Granting Authority and it was a part of the “Instruction to Bidders” for that particular road project. This list is used during the Procurement Stages of the road project and it is quantified and included in the Financial Close. The Financial Close was not a cardinal part of the Project Agreement. The Financial Close and risk quantification has never been revealed to the researcher due to its commercial sensitivity. In the project context the risks are analysed iteratively. In Fig.1 a risk framework with iterative flow is shown. PFI risks and risk management is explained in detail in above.

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Fig.1. Iterative Risk Management Framework in PFI Road Projects

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Table 1. Risk Allocation Matrix Risk Ownership Risk Description Construction Risks: 1. Environmental Pollution 2. Results of further Environmental Studies 3. Archaeology finds during construction 4. Protester action 5. Delay to Construction Progress/Completion 6. Adverse Weather 7. Insufficient land (beyond Land Made Available and Access Rights) 8. Public Utilities 9. Contractor Insolvency 10. Construction inflation variance 11. Construction noise 12. Pest damage 13. Traffic Management 14. Road Safety Audit 15. Accommodation Works 16. Planning amendments/delay (compliant bid) 17. Planning amendments/delay (variant bid) Ground Condition Risks: 18. Soft ground 19. Hard ground 20. Ground Water 21. Mine Workings 22. Rock quality and presence Pre-contract risks: 23. Change in Interest Rate 24. Employee Requirements Changes 25. Scheme Cost Increases 26. Inflation Risk Third Party Risks: 27. Relevant Authorities 28. Interested Parties

Granting Authority

SPV

Shared


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Risk Ownership Risk Description

Granting Authority

Design Risks: 29. Change in quantities 30. Changes from initial design 31. Change in design standards 32. Employers’ Requirement Changes 33. Council and Contractor Solution Changes Legislative, Financial and Economic Change Risks: 34. General Change in Law 35. Interest Rate Risk (Post Financial Close) 36. V.A.T. Status Risk 37. Inflation Risk 38. Availability Risk 39. Traffic Usage Risk 40. Performance Risk Operation and Maintenance Risks: 41. Unforeseen Defects (including pavement failure) 42. Accident Damage 43. Vandalism 44. Weather 45. Traffic Loading 46. Renewal and Replacement of Structures and Infrastructures 47. Utilities Access 48. Replacement of drain, signs, barriers, etc. 49. Pavement patching 50. Existing structures failure 51. Hand back inspections 52. Road Safety Audits 53. Staff Costs 54. Inadequate performance of subcontractors 55. Force Majeure 56. Termination for Contractor Default 57. Other Termination

SPV

Shared

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Due to the long concession periods of PFI projects, the temporal aspects of risk are particularly important. The case study project have a 30 year concession period and the impact and probability of occurrence of a particular risk type changes as the project advances through the different project stages. As a consequence of this the uncertainty can either decrease or increase. The uncertainty attached to each risk is the key factor in managing it. With high uncertainty few mitigation measures are realistically available and if uncertainty can be reduced, the risks can be better managed and the possibility for project success increases. PFI projects are viable only if a reliable, long-term revenue stream can be established. The risk that the predicted revenues do not materialise is the greatest risk to the commercial viability (Grimsey and Graham, 1997). This risk is borne by those providing finance or financial guarantees. The critical question is whether revenue streams can cover operating costs, service debt finance and provide returns to risk capital. The profits of enterprise are a reward for facing this uncertainty (Grimsey and Lewis, 2002). Risks can be broadly categorised as global or elemental (Merna and Smith, 1996). Global risks are those risks that are normally allocated through the project agreement and typically include political, legal, commercial and environmental risks. Elemental risks are considered as those associated with the construction, operation, finance and revenue generation of the project. It is important to look at the nature and quantities of risk from the different perspectives of the main parties to a PFI project. The risk quantification tool Multiple Estimating Using Risk Analysis (MERA) consists of producing a conventional base estimate using an appropriate technique to the level of information available. This base estimate (BE), which includes no allowance for risk, is accompanied by an analysis of known and predictable risks associated with the project. Each risk is then allocated an average risk estimate (ARE) and a maximum likely estimate (MRE). The risks from the empirical data provided by the Granting Authority are grouped in the SLEEPT (Social, Legal, Economic, Environmental, Political, and Technological) Framework. The quantified risk with dummy data was presented and validated at the SPV’s head office with the presence of company managers directly involved in the management of the case study projects for this thesis. The composite risk criteria weighting of the analysis show clearly that economic and technological risk criteria scored the highest weighting. This is a powerful tool for structuring the whole life cycle of a PFI road project and decision making. Dummy data was required since the Granting Authority and SPV declined to reveal the quantified risk register claiming commercial confidentiality.


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An issue that has emerged from the evaluation of the case studies is the emergence of differentiated Risk Profiles; differentiated by the class of party to the project and also differentiated by the prioritisation of the features for the specific PFI project. Four generic groups of parties within a PFI project are: 1. 2. 3. 4.

the Public Sponsor; the Concessionaire (SPV); the Lenders; the Contractors.

There are also four generic risk categories features of PFI that can be identified within each PFI project: 1. the Value for Money achieved within the Project; 2. the Robustness of the Project Arrangements; 3. the overall Affordability of the project scheme; 4. the Risk Transfer Approach. This creates a 4x4 matrix of potentially competing objectives that need to be managed to deliver a successful project. The Value for Money (VFM) Risk Category relates primarily to the Public Sponsor who has a statutory duty to demonstrate that their expenditure is being managed effectively and efficiently. This is typically done by reference to the PSC. It should also be remembered that the private parties within a PFI project all have a requirement to conduct profitable business, thus they will have their own ‘VFM’ evaluation requirements. PFI projects are supposed to generate ‘win-win’ opportunities rather than the more orthodox ‘win-lose’ situations. The Robustness Risk Category of the Project arrangements refers to the congruence of the individual aims with the main project objectives. The project arrangements should be equitable between all parties, such that all parties should have the ability to complete a particular project without the necessity for ‘stepin’. Thus no party perceives the agreement as ‘unfair’. All parties should feel that they have not been disadvantaged by the arrangements. A satisfactory Robustness arrangement would be one that all parties would be prepared to execute for subsequent projects. HM Prison Service (mentioned in Chapter 4) identified this as a major risk when it publicly stated that it had forgone significant initial savings on the first two projects in order to create a long term competitive market in PFI Prison provision. A further question relating to the robustness of PFI project arrangements is the level of up-front ‘risk capital’ necessary to develop a PFI project. It is accepted that the ‘at risk’ capital needed for a PFI development has increased, however this is reflected in the level of ‘profitability’ sought within the PFI repayment model to demonstrate the ‘bankability’ of the project. The project case studies have identified that an

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important stimulant to successful development of PFI is the previous expertise within a market sector that the prospective bidder can draw upon when developing the proposal. The overall Affordability Risk Category of the project relates to the ability of all parties to complete the project with the available resources. The Public Sponsor has to ensure that it has access to funds, and that the expenditure of the available funds provides an adequate return when compared with other alternative investments. The private parties need to ensure that they have access to sufficient finance and other resources to complete the project and obtain an income from the operation of the facility over the concession period. In PFI road projects these are the shadow toll band payments. The aim of such a payment structure is to allocate a sufficient element of volume risk to the SPV and also to limit the authority’s exposure to an increase in payments arising from a greater than anticipated volume of traffic on the road. This is not necessarily guaranteed. The Risk Transfer Approach Category refers to the balance achieved within the agreements between all of the parties in relation to accepting the financial consequences should a risk occur on a particular PFI project. As an illustration, Best Practice Guidance confirms that a risk should be allocated to the party best able to manage and control the risk. In the Prison Case studies a complete round of tendering was rendered invalid because the Public Sponsor had attempted to transfer the occupancy risks to the Concessionaire, when it is patently obvious that the Public Sponsor, HM Prison Service, was the only party that could manage the risk associated with the number of prisoners sent to a PFI prison. The combination and balance between Risk Transfer, Robustness, VFM, and Affordability needs to be considered holistically. The risk register from a road is taken and identified and allocated the risk to those parties significantly affected by the occurrence of a particular risk. It should be noted that risks can impact on more than a single stakeholder in the project. Some risks can impact on all parties which can be seen from the tables. Equally some risks can impact on VFM, Robustness, Affordability and Risk Transfer. The risk allocation was presented to the stakeholders for approval and comment. The stakeholders approved the presented risk allocation. Tables 2-5 represent the arithmetic count of the identified features (VFM, Robustness, Affordability, and Risk Transfer) for each SLEEPT category of risk for each stakeholder in the PFI Road Project.


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Table 2. Summary of Critical Collated Features for Public Sponsor FEATURES

NO. OF RISK CATEGORY (SLEEPT)

VFM

ROBUSTNES S

AFFORDABILIT Y

RISK TRANSFE R

SOCIAL

1

1

1

1

LEGAL

1

4

4

4

4 (7.84%) 13 (25.49%)

ECONOMICAL

6

5

5

5

21 (41.18%)

ENVIRONMENTAL

0

1

1

1

POLITICAL

2

3

3

2

TECHNOLOGICAL

0

0

0

0

TOTAL

10 (19.61 %)

14 (27.45%)

14 (27.45%)

13 (25.49%)

TOTAL

3 (5.88%) 10 (19.61%) 0 (0.00%) 51 (100.00% )

Table 3. Summary of Critical Collated Features for SPV (Special Purpose Vehicle) TOTAL

FEATURES


VFM

ROBUSTNESS

AFFORD ABILITY

RISK TRANSF ER

SOCIAL

3

2

2

3

LEGAL

2

5

6

6

ECONOMICAL

13

17

16

14

ENVIRONMENTAL

0

4

4

4

POLITICAL

2

3

3

2

TECHNOLOGICAL

8

9

9

3

TOTAL

28 (20.00%)

40 (28.57%)

40 (28.57%)

32 (22.86%)

10 (7.14%) 19 (13.57%) 60 (42.86%) 12 (8.58%) 10 (7.14%) 29 (20.71%) 140 (100.00%)

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Table 4. Summary of Critical Collated Features for Lenders FEATURES


VFM

ROBUSTNES S

AFFORDABILIT Y

RISK TRANSFE R

SOCIAL

0

0

0

0

LEGAL

1

2

2

2

ECONOMICAL

6

8

7

8

ENVIRONMENTAL

0

0

0

0

POLITICAL

2

3

3

2

TECHNOLOGICAL

0

0

0

0

TOTAL

9 (19.57 %)

13 (28.25%)

12 (26.09%)

12 (26.09%)

TOTAL 0 (0.00%) 7 (15.22%) 29 (63.05%) 0 (0.00%) 10 (21.73%) 0 (0.00%) 46 (100.00% )

Table 5: Summary of Critical Collated Features for Contractors


FEATURES VFM

ROBUSTNESS

AFFORD ABILITY

RISK TRANSF ER

TOTAL

SOCIAL

3

4

2

2

11 (9.17%)

LEGAL

2

3

4

4

13 (10.84%)

ECONOMICAL

9

14

13

11

47 (39.17%)

ENVIRONMENTAL

0

4

4

4

12 (10.00%)

POLITICAL

2

2

2

2

8 (6.66%)

TECHNOLOGICAL

3

11

11

4

29 (24.16%)

TOTAL

19 (15.83%)

38 (31.67%)

36 (30.00%)

27 (22.50%)

120 (100.00%)


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Table 6. Summary of Collated Features for each of Stakeholders in the PFI Road Projects CRITICAL COLLATED FEATURES (%) RISK STAKEHOLDERS

VFM

ROBUSTNESS

AFFORDABILITY TRANSFER

PUBLIC 19.61

27.45

27.45

25.49

SPV

20.00

28.57

28.57

22.86

LENDERS

19.57

28.25

26.09

26.09

CONTRACTORS

15.83

31.67

30.00

22.50

SPONSOR

Figure 4 represent an analysis of the proportionality of the critical collated features for different stakeholders in PFI road project. CRITICAL COLLATED PFI ROAD FEATURES FOR DIFFERENT STAKEHOLDERS (%) VFM

RISK TRANSFER

35 30 25 20 15 10 5 0

AFFORDABILITY

ROBUSTNESS

PUBLIC SPONSOR SPV LENDERS CONTRACTORS

Fig. 2: Critical Collated PFI road features for different stakeholders

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Table 7: Summary of Critical Collated Features for Contractors FEATURES


VFM

SOCIAL

ROBUSTNESS

AFFORD ABILITY

RISK TRANSF ER

3

4

2

2

LEGAL

2

3

4

4

ECONOMICAL

9

14

13

11

ENVIRONMENTAL

0

4

4

4

POLITICAL

2

2

2

2

TECHNOLOGICAL

3

11

11

4

TOTAL

19 (15.83% )

38 (31.67%)

36 (30.00%)

27 (22.50%)

TOTAL

11 (9.17%) 13 (10.84%) 47 (39.17%) 12 (10.00%) 8 (6.66%) 29 (24.16%) 120 (100.00%)

Reservation: The collated summary tables are a representation of the arithmetic count of identified features. No work has yet been executed to quantify the proportional contribution of each feature. This paper treats all features in an identical manner. Detailed quantification work is ongoing. Table 8: Summary of Collated Features for each of Stakeholders in the PFI Road Projects CRITICAL COLLATED FEATURES (%) STAKEHOLDERS VFM

ROBUSTNESS

AFFORDABILITY

RISK TRANSFER

PUBLIC SPONSOR

19.61

27.45

27.45

25.49

SPV

20.00

28.57

28.57

22.86

LENDERS

19.57

28.25

26.09

26.09

CONTRACTORS

15.83

31.67

30.00

22.50

The risks from the empirical data provided by the Granting Authority are grouped in the SLEEPT (Social, Legal, Economic, Environmental, Political, and Technological) Framework. The quantified risk with dummy data was presented and validated at the SPV’s head office with the presence of company managers


77

directly involved in the management of the case study projects for this thesis. The composite risk criteria weighting of the analysis show clearly that economic and technological risk criteria scored the highest weighting. This insight is a powerful tool for structuring the whole life cycle of a PFI road project and decision making. In traditional risk analysis neither the stakeholder party nor the generic features are separately identified. The analysis of the Critical Collated features shows clearly that the SPV and Contractors bear most of the risk features. The Public Sponsor and Lenders are protected by the Concession Agreement from the risk features. The result is shown in Table 9. Table 9. Collated Summary of Number of Risk Category (SLEEPT) versus Stakeholders in a PFI road project NO. OF RISKS BY CATEGORY (SLEEPT) SOCIAL LEGAL ECONOMICAL

PUBLIC SPONSOR 4 13 21

ENVIRONMENTAL POLITICAL TECHNOLOGICAL COLLATED TOTAL

3 10 0 51 (14.69%)

STAKEHOLDER SPV LENDERS

CONTRACTOR

10 19 60

0 7 29

11 13 47

12 10 29 130 (37.46%)

0 0 0 46 (13.26%)

12 8 29 120 (34.59%)

COLLATED TOTAL 25 (7.20%) 52 (14.98%) 157 (45.24%) 27 (7.78%) 28 (8.07%) 58 (16.73%) 347 (100.00%)

Figures show the spider diagram for different stakeholders in the case study PFI road project.

78


RISKS BY CATEGORY (SLEEPT) FOR STAKEHOLDERS IN PFI ROAD PROJECT SOCIAL

60 50 40 TECHNOLOGICAL

LEGAL

30 20 10 0

POLITICAL

ECONOMICAL PUBLIC SPONSOR SPV LENDERS ENVIRONMENTAL

CONTRACTOR

Fig. 3. Spider Diagram for Risk Category for Stakeholders

RISK CATEGORY (SLEEPT) FOR PUBLIC SPONSOR

SOCIAL 25 20 TECHNOLOGICAL

15

LEGAL

10 5 0

POLITICAL

ECONOMICAL

ENVIRONMENTAL

Fig. 4. Risk Category (SLEEPT) for Public Sponsor

PUBLIC SPONSOR


RISK CATEGORY (SLEEPT) FOR SPV SOCIAL

60 40 TECHNOLOGICAL

LEGAL

20 0 POLITICAL

ECONOMICAL

ENVIRONMENTAL

SPV

Fig. 5. Risk Category (SLEEPT) for the SPV

RISK CATEGORY (SLEEPT) FOR LENDER

SOCIAL

30 TECHNOLOGICAL

20

LEGAL

10 0 POLITICAL

ECONOMICAL

ENVIRONMENTAL LENDER

Fig. 6. Risk Category (SLEEPT) for the Lenders

79

80


RISK CATEGORY (SLEEPT) FOR CONTRACTOR SOCIAL

50

TECHNOLOGICAL

40 30

LEGAL

20 10 0

POLITICAL

ECONOMICAL

ENVIRONMENTAL CONTRACTOR

Fig. 7. Risk Category (SLEEPT) for Contractors From the case study it was understood that the risk framework for the project existed but it was not being applied consistently. The Public Sector always tried to transfer all risks and Private Sector accepted too many (and for some they had no mechanism of control). The study has shown that the risk framework can be applied in an improved way to offer greater clarity in the risk input and the implications of risk transfer.

Summary Construction is a complex and dynamic industry; and the main procurement parameters are time, cost, quality and certainty. A managed approach to risk is a means for providing the client with fewer surprises and greater certainty. Central to all PFI transactions are the contractual agreements put in place between the parties and these define each party’s roles making clear their expected requirements and liabilities. The contractual agreements define the apportionment of risk between the contractual parties. The incorporation of a risk register with identified risk owners as an addendum to the contracts clarifies the liabilities and responsibilities of the parties. A fundamental principle of a PFI project is that risks associated with the implementation and delivery of services should be allocated to the party that is


81

best able to manage the risk. In a PFI concession, the Government’s view has been that it is reasonable to expect the project consortium (SPV) to take on systematic risk. Systematic risks can be classified as economic risk, legislative risk, taxation risk and financial arrangements. The financing arrangement risk crosses the boundary between construction and operation and may persist for the life of the contract and beyond; although there has been a tendency for refinancing early in the concession period. The Consortium Company (SPV) has separate contracts for the Construction Contractors and for the Operation and Maintenance Contractors and may have Services Contracts. The reason for this is to permit further transfer of risks to the party which has the ability to manage that risk. In this study the so-called SLEEPT methodology is utilized as a risk management tool within the domain of a PFI road project in the UK. The risks from the empirical data provided by the Granting Authority are grouped in the SLEEPT (Social, Legal, Economic, Environmental, Political, and Technological) Framework. The quantified risk with dummy data was presented and validated at the SPV’s head office with the presence of company managers directly involved in the management of the case study project for this paper. The composite risk criteria weighting of the analysis show clearly that economic and technological risk criteria scored the highest weighting. This insight proved to be a powerful tool for structuring the whole life cycle of a PFI road project and decision making.

REFERENCES [1]

PMI (2000), A Guide to the Project Management Body of Knowledge: PMBOK [Project Management Book of Knowledge] Guide. (2000 edition). Upper Darby, PA: Project Management Institute.

[2]

APM (1997), PRAM Project Risk Analysis and Management Guide. Association for Project Management, Norwich, UK.

[3]

Chapman, C. & Ward, S. (2003), Project Risk Management – Processes, Techniques and Insights, 2nd Ed., John Wiley & Sons Ltd., Chichester, West Sussex, England.

[4]

Loosemore, M., Raftery, J., Reilly, C., & Higgon, D. (2006), Risk Management in Projects, 2nd Edition. Taylor & Francis, New York.

[5]

Cooper, D., Grey, S., Raymond, G. & Walker, P. (2005), Project Risk Management Guidelines – Managing Risk in Large Projects and Complex Procurements, John Wiley & Sons Ltd., Chichester, West Sussex, England.

[6]

Jackson, P.M. (2004) ‘The Private Finance Initiative. From the foundations up-a premier’, Hume Occasional Paper No.64. The David Hume Institute.

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[7]

HM Treasury Taskforce (1997) ‘Partnerships for Prosperity’: The Private Finance Initiative, Treasury Taskforce Guidance, November, London.

[8]

Illidge, R. and Cicmil, S. (2000) ‘From PFI to PPP: Is Risk Understood?’ Bristol Business School Teaching and Research Review, Issue 2, Spring, ISSN 14684578.

[9]

Smith, A. (2001), Speech by Chief Secretary to the Treasury at the OGC PUK Conference 23rd October.

[10]

Gallimore, P., Williams, W. and Woodward, D. (1997) ‘Perceptions of risk in Private Finance Initiative’. Journal of Property Finance, Vol.8, No.2, pp.164-176. ISSN 0958-868X.

[11]

HM Treasury Taskforce (1995) ‘How to construct a Public Sector Comparator’ Technical Note 5, Office of Government Commerce (OGC), London.

[12]

Fox, J. and Tott, N. (1999) ‘The PFI Handbook’. Herbert Smith – Jordan Publishing Limited.

[13]

Smith, N.J. (1999) ‘Managing Risk in Construction Projects’, Blackwell Science, Oxford.

[14]

HM Treasury (2003) The Green Book: Appraisal and Evaluation in Central Government, London, HMSO.

[15]

Eaton, D. (2003), ‘Price Bidding, Bid Evaluation and Financial Management’ Lecture Programme 2003/2004 University of Salford, School of Construction and Property Management, SCPM.

[16]

Liu,J., Flanagan, R. and Li,Z. (2003) ‘Why does China need risk management in its construction industry?’ ARCOM, Nineteenth Annual Conference, Sept.3-5, pp.453-462, University of Brighton.

[17]

Mills, A. (2001) ‘A systematic approach to risk management for construction’. Structural Survey, Vol.19, No.5, pp.245-252.

[18]

Eaton, D. (2004a) ‘Introduction to Risk Management’ Presentation on April 27th in the University of Sakarya, Turkey.

[19]

Eaton, D. (2004b) ‘Risk Transfer in PFI’ Presentation on April 27th in the University of Sakarya, Turkey.

[20]

Grimsey, D. and Graham, R. (1997), PFI in the NHS. Engineering, Construction and Architectural Management, 4(3), pp.215-231.


83

[21]

Grimsey, D. and Lewis, M.K. (2002), Evaluating the risks of public private partnerships for infrastructure projects. International Journal of Project Management, 20, pp.107-118.

[22]

Merna, A. and Smith, N.J. (1996), Privately Financed Concession Contract, Vols.1 and 2. 2nd ed. Hong Kong: Asia Law and Practice.

Ali ATE Duzce University Tehnology Faculty, Civil Engineering Department, Konuralp Kampus, Duzce, Turkey. Email: [email protected]

DETERMINATION OF DESIGN EARTHQUAKE MAGNITUDE BY DETERMINISTICAL APPROACH IN DUZCE DISTRICT, TURKEY Keywords: Earthquake, hazard, Deterministic, Düzce Abstract This study presents an evaluation of earthquake risk in Duzce city in Turkey. The seismicity of Duzce has been suyveyed by using the earthquakes M 5.0 that occurred in the region for the time interval 1967-2003.This study has been performed utilizing time independent probabilistic model to predict the future earthquakes activities. The North Anatolian Fault (NAF), which runs through the northern region of Turkey (between the Eurasian and Arabian plates), has been highly Known in recent years due to a couple of large earthquakes that occurred along the (NAF) way. Recently, a magnitude 7.2 earthquake struck Duzce city on November 12, 1999; its epicenter located in the town of Duzce. Available reports indicate that more than 100 buildings were destroyed, approximately 400 confirmed dead and over 800 injured. Turkey has a long history of major ground shaking along the North Anatolian Fault. The seismicity along this fault is dominated by intermediate to large magnitude events with relatively few small events. Since 1939, there have been 11 magnitude 6.7 or greater earthquakes along the fault, (nine of which had magnitudes greater than 7.0) making it one of the most seismically active right-lateral strike-slip faults in the world. These previous earthquakes follow a pattern that progresses generally in the western direction along the fault. The North Anatolian Fault extends more than 1400 km. A right-lateral fault is one that, if an observer was standing on one side of the fault looking towards the other side, the observer would see the ground on the other side of the fault move to the right. A strike-slip fault describes the relative motion of the ground on either side of the rupture as parallel to the fault direction.

Introduction Turkey lies among the Mediterranean part of the Alpine-Himalayan orogenic system. The Alpine orogeny is result of the compressional motion between Africa and Europe; however the Himalayan orogeny is produced as a result of the India-Asia collision. The seismicity distribution among the Alpine-Himalayan system is not homogenous, which concentrates mostly along the plate margins. The African, Arabian

86

Ali Ate

and Eurasian plates are involved in the tectonics of the Mediterranean region [McKenzie, 1970]; however the eastern Mediterranean is more complicated (Fig.1). The reason of the local increase in seismic activity in the region may be because of the rapidly moving smaller plates [Erdik et al. 1985]. Düzce, known by very high seismicity, is situated very close to the North Anatolian Fault (NAF), one of the most seismogenic faults in the world. The latest event occurred in 1999 (Ms = 7.2), following the even larger Kocaeli earthquake (Ms = 7.8), less than one hundred kilometers away, always along the North Anatolian Fault. The Kocaeli earthquake (Ms = 7.8), affected residential parts and several cities, including Düzce. 12 November 1999 Duzce earthquake in Turkey caused considerable hazard to residential and commercial buildings, public facilities and infrastructures with substantial casualties. The epicenter of the earthquake was located about 6 km south of Duzce. The water and the sewage system were heavily damaged due to ground deformations and shaking. Damage to the transport infrastructure observed along the 60 km of the AnkaraIstanbul highway crossing the Duzce Fault.

. Fig. 1. Location map showing the different plates that influenced the structural evolution of southeast Turkey [Bozkurt, 2001]

Determination of design earthquake magnitude by deterministical approach in ...

87

Study area and morphology Gölyakaq is situated near the Ankara- stanbul Motorway in the North West in Turkey (Fig.2). It is on the wets side of the Efteni lake and is sorrounded by local and North Anatolian Fault Zone. It is about 50 km to Black Sea. The Studty area is situated on a flat area and haa an altitude between 140- 160 m. The sutudy area is situated on the North of the central section, while the comprehensive topographical inclination is from south west to north due to the majör hills in the region. The topographical inclination in the residential areas varries between 30 to 10 % down.

Fig 2. Study area

Tectonics, seismo-tectonic The thicness of thr Quaternary- aged units, that have liquefactionand settlement potential change from 30-50 m and 0-30 norh west of the study area and the other settlements, respectively. The vertical and horizontal transitions at shoet distances exist within the the Quaternary units. The study area underlain by loose and silty Quaternary units, liquefaction susceptibility of loose sedimantary is medium to high (Fig. 3). The ground water map was prepared from data obtained by water depths

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measurements in 35 boreholes during April of 2015 (Fig. 4). The groundwater table depth canges from 3m to 5 m.

Fig.3. Geological map of study area [M.T.A]

Fig. 4. Unger ground water table map

Although this province is one of the most seismic active site in worldwide there was not reliable recordings from previous earthquakes. Considerable reliable data are available for the last century. The demonstrative and more representative of the seismicity on North Anatolian Fault (NAF) are shown on the figure below (Fig.5, Fig.6).


Fig.5. Distrubuton of histaorcal earthquakes in 100 km radius in Duzce vicinity

Fig. 6. Earthquakes occurred on NAF Activity in Turkey since 1939 [Kalafat et al.2001]

89

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Ali Ate

Method Hazard evaluation of ground motion is performed due to the specific seismic scenario. The seismic approach consists of assuming an earthquake which has a clear size occurring at a known place. A charecteristical sampling of deterministic seismic assessment analysis can be described as as below [Reiter, 1990]. Fistly, earthquake sorces in pertinent area yielded a particular ground motion should be identified and sources are to examined from the aspect of the geometry. After then, shortest distance assigned perpendicular from each source to center of location site should be determined.It is assumed to imagnary distance closest way to center of site considering flying bird over the area. Third phase, it is fundementally the choice of earthquake estimated effective shaking. Different ground motion parameters widely known as shaking at this certain site. This considetarion is provided by confronting the degree of vibrating the yielded by earthquakes supposed and then realize at a distance assigning above. The prodominant arthquake is described with the help of the its size and distance from site. Lastly, risk at a certain place is clearly described and similarly via ground motion estimated at pertinent area provisional earthquake. Charectersitics of specific earthquake are generally defined with the help of more than one ground motions parameters acquired from forecastive basic correlations about ground motions parameters. Earthquake risks is generaly assessed with the peak velocity,and response epectrum due to site [Saha et al.,2012]. The DSHA approach is delineated in below (Fig.7). The description is explained in four phaes, ana DSHA is shown to be a fairly basic approaches. DSHA generally explains the wost case scenario and is quite convenient for important structures. Neverthless, it does not exist any knowledge on probability of events of the prodominant earthquake, probability of earthquake taking place in which the earthquake is supposed to take place, ther degree of vibrating which could be forecasted pending a time, or the effects of doubts in the various stages necessitated to calculate the concluding ground motion parametes [Kramer,1996].


91

Fig. 7. Four-steps process of a deterministic seismic hazard assessment [Kramer, 1996]

Earthquake sources and charecterization The phases of defination including characterization of earthquake sources are related with the description of the seismic and their productivity of earthquake potential. In this scope, Either line or area sources were utilized for model style. In this context, there are three main faults in Duzce city; first fault is named Duzce fault that is a brunch of (NAF) and has a lenghth of 75km and is away from 13 km from Duzce center. Second fault is entitled as a Hendek fault and has a length of 29 km and is away from 22 km from Duzce center. As regarding last fault is known as Çilimli fault and is independent from NAF and identified as local fault .It has a length of 22 km and is away from 36 km from study area (Fig.8). The practical regressonal relation relating magnitude and fault displacement and fault rapture length or rupture area, were offered by Bonilla et al. [1984], Slemmons et al. [1989] alongwith Wells and Cooppersmith [1994]. Considering the assumption that ½ of the total length of fault would rupture when it generates the maximum earthquake [Mark, 1977]. Duzce fault yielded maximum a magnitude of Mw=6.8.

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Concluding of this operation involving the maximum magnitude potential determining were obtained in the table (Table.1).

Fig.8. Dominant fault in Duzce vicinity

Table 1. Critical tectonic fault and maximum moment magnitude Fault Name

Duzce

Hendek Çilimli

Fault Length

75 (except of cracked part in 1999 earthquake) 29 22

Maximum magnitude Potential

Accecpted Maximum Magnitude, Mw

Wells and Coppersimith [1994] 6.9

Slemmons et al. [1989]

Bonilla et al.[1984]

7.2

7.0

7.2

6.79 6.7

7..0 6.9

6.8 6.8

7.0 6.9


93

Determınatıon of peak ground horızontal accelaretaıon The phase choice of prodominant earthquake related to the assessment of peak ground horizontal accelaration of owing to various sources at the site of concern. In fact, if the vibrating degree was supposed to be charecterized adequately by PHA, and then a convenient attenuation relation may be used for checking earthquake choice. Based on the the largest and maximum moment magnitude likelihood of ititative source and and closest distance from center of the city, the horizontal accelerations estimated at the center were detected using the specific attenuation rules. The maximum horizontal accelerations were detected bu utilizing attenuation criterias offered by Campell and Bozorgnia [2003], Ambrays [1995], Inan et al [1996], Aydan et al [1996]. These accelaration values around the closest distance to the three seismic sources according to the proximity were obtained in Table 2. In this sdtudy, it is resulted that the critical tectonic structure for Duzce is Duzce fault which can pruduce the prodominant earthquake of magnitude 7.1 at 35 km. Table 2. Critical tectonic fault and maximum moment accelerations Tectonic Cracking

Duzce Fault Hendek Fault Çilimli Fault

Maximum Magnitude (Mw)

Distance From Source to Center (km)

Peak Horizontal Aceleration (g)

Average

7.2

13

Campell and Bozorgnia [2003] 0.53

Ambraseys [1995]

Inan et al [1996]

Aydan et al [1996]

0.52

0.51

0.53

0.53

7.0

22

0.48

0.46

0.47

0.47.2

0.48

6.9

36

0.42

0.41

0.40

0.42

0.42

Conclusions In this reasearch, Duzce Fault to be produced maximum earthquake was selected as the appropriate deterministic scenario for Duzce city comparing the other faults in the vicinity of Duzce. Maximum magnitude capacity determination for various faults around Duzce provision concluded in the maximum value of Duzce fault. Duzce put forward the maximum value of seismic hazard from the Duzce fault. The parameters are obtained as earthquake moment magnitude Mw=7.1 and peak

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horizontal acceleration is a=0.53. Depending on the seismic risk values obtained in Duzce city and has various criteria. It is infered that Duzce is placed at a high seismic risk area.

REFERENCES [1]

McKenzie, D.P. 1970. Plate tectonics of the Mediterranean region, Nature, 220, 239-343.

[2]

Erdik M, Doyuran V, Gulkan P, Akkas N (1985) “A probabilistic assessment of the seismic hazard in Turkey” Tectonophysics 117, pp. 295- 344

[3]

Bozkurt, E. 2001. Neotectonics of Turkey-a synthesis. Geodinamica Acta, 14, 330.

[4]

General Directorate of Mineral Research and Exploration, Geological Map of Turkey, Ankara, map. Opening qualified 1/100000 Scaled Adapazarı G24 paftas no: 31, Publications of General Directorate of Mineral Research and Exploration, 2002 (In Trkish).

[5]

General Directorate of Mineral Research and Exploration, Geological Map of Turkey, Ankara, map. Opening qualified 1/100000 Scaled Adapazarı G24 paftas no: 31, Publications of General Directorate of Mineral Research and Exploration, 2002 (In Turkish).

[6]

Kalafat, D., T. Ö. Tahao lu, A. M. I ıkara (2001). 9 A ustos 1912 SarosMarmara Depremi, Türkiye 14. Jeofizik Kurultayı ve Sergisi, Geni letilmi Sunu Özetleri Kitabı (Extended Abstracts Book) s. 103-106, MTA Kültür Merkezi, 811 Ekim 2001, Ankara (in Turkish).

[7]

Richter C.F (1958) “Elementary Seismology” Freeman, San Francisco CA, pp. 768

[8]

Saha et al.(2012) “Deterministic Seismic Hazard Assessment of Quetta, Pakistan”, 15.WCEE LISBOA, 2012.

[9]

Kramer, S.L., Geoteknik Deprem Mühendisli i, Çeviren: Kamil Kayabalı, Gazi Kitabevi, Ankara, 2003.

[10]

Bonilla, M.G, Mark R.K., and Lienkaemper J.J. (1984). Statistical relation among earthquake magnitude, surface rupture and surface fault displacement. Bulletin of the Seismological Society of America 74:6, 2379-2411.

[11]

Slemmons, D.B., Bodin, P., and Zhang, X. (1989). Determination of earthquake size from surface faulting events, in Proceedings, Int. Seminar on Seismic Zoning, China.

[12]

Wells D.L Coppersmith K.J (1994) “New empirical relationships among magnitude, rupture length, rupture width, rupture area and surface displacement” Bull. Seismol. Soc. Am. 4 (84), pp.975-1002


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[13]

Mark R.K (1977) “Application of linear statistical model of earthquake magnitude versus fault length in estimating maximum expectable earthquakes” Geology 5, pp.464-466.

[14]

Campbell, K.W., and Bozorgnia, Y. (2003). Updated near-source ground-motion (attenuation) relations for the horizontal and vertical components of peak ground acceleration and acceleration response spectra. Bulletin of the Seismological Society of America. 93:1, 314–331.

[15]

Ambraseys N.N. (1995) ”The prediction of earthquake peak ground acceleration in Europe”. Publ. Earthquake Engineering and Structural Dynamics, 24, pp.467490.

[16]

Inan E, Colakoglou Z, Koc N, Bayulke N, Coruh E (1996) “Earthquake catalogues with acceleration records from 1976-1996” General Directorate of Disaster Affairs, Earthquake Research Division, Ankara, Turkey, 98pp (in Turkish).

[17]

Ayadan O, Sezaki M, Yarar R (1996) “The seismic characteristics of Turkish earthquakes” 11th World Conference on Earthquake Engineering, Acapulco, Mexico, CD paper no 1025

Ali ATE

1

Latif. O. UGUR2 Rifat AKBIYIKLI3 Inan KESKIN4 Burak YE IL5 Caner DEMIRDAG6 1Dr. Instructor, Düzce Üniversity Teknology Faculty Civil Engineering Department Konuralp, DÜZCE/Turkey e-mail:[email protected], 2Duzce Üniversityi Duzce Vocvational School Construction Department, 81010 Düzce / Türkiye

e-mail: [email protected] 3 Duzce universty Master of Science StudentCivil Engineering Department, 81010 Düzce / Türkiye

e-mail: [email protected]

INVESTIGATION OF DAMPING ACCELERATION RATIO AND SITE EFFECTS ON SEISMIC GROUND RESPONSE IN THE DUZCE REGION, TURKEY Keywords: Soil amplification,site conditions peak groundaccelerations

Abstract The city of Duzce in Western Black Sea Turkey has a experienced of a destructive earthquake with Mw=7.2 in 1999 Duzce earthquake and is situated on the highly active Eursasian plate. The North Anatolian Fault Zone (NAFZ) crosses through Turkey from east to West; earthquake occured on this fault on August17, 1999 (Kocaeli) and November 12, 1999 (Düzce). Regional geology and subsoil conditions can change the site charecteristics of ground motion. Thus, detecting the soil magnification at the time of occuring an earthquake, especiallyfor weak soils, is crucial subject for investigators. In this research, one dimensional ground response behavior analyses were exucuted for Gölyaka area utilizing the August 17, 1999 Duzce e record with arthquake strong ground motion with DEEP SOIL software. Soil charecterstics and depth to engineering bedrock at the Gölyaka sites are various and the observed level of the constructional hazard at Gölyaka region at the time of occuring the Duzce earthquake was different as well. Findings revealed that higher magnifications ratios occur at higher periods due to soil behaviour. Result of this research revealed that local geological conditions can magnify ground motion at some periods and, acording to the amplification, and obtained

98 Ali Ate , Latif. O. Ugur, Rifat Akbiyikli, Inan Keskin, Burak Ye il, Caner Demirdag response spectra can exceed the suggested design spectra. As aresult, it is appearent that local site conditions should be taken into consideration for earthquake- resistant engineering designs on soft soils.

1.Introduction Turkey is situated on a one of area the World’s major and the most dangererous erathquake zone (Fig. 1). Moreff over, the Marmara region, that is a heavily industrialized and populated area placed in the Northwestern Black sea in Turkey. This region is subjected to devastating earthquakes. The August 17, Adapazarı and Kocaeli 1999 and November 12, 1999 Duzce earthquake are examples of recent destructive earthquakes. Especially, the No vember 12, 1999 Duzce earthquake affected a large part of the Duzce and its environments. One of the most important properties of hazards is foundation concerned defects of structures, such as tilting, overturning and sinking. Duzce area is situated on young flood-plain deposits of the allivium sediments around the Efteni Lake. For this reason, soft soil- deposits are considered to play a important role in these damages. The amplitute of seismic waves goes up while they go trough weak soil stratums near the earth’s surface. This kind of study is called the site amplification. There are some investigators who have surveyed the effect of local site conditions on structure defects in literature [Çetin et al. 2002; Tezcan et al. 2002; Sancio et al. 2002; Ozel and Sasatani 2004; Fırat et al. 2009]. Pertinent investigations have revealed that site effects may be noticed to detect the behaviour of structures under the effect of the seimic load.

Fig. 1. Main tectonic properties of Turkey [Gülen et al.2000]

Investigation of damping acceleration ratio and site effects on seismic ground ...

99

Local ranges on the attributes of alluvial sediments in Duzce come out to play an importnat role in the occurance and non-occurance of ground defects and joined structures. Basic judgement of site data offers that type and width of buildings has no clearly affect the degree of ground defects. Neverthless, localization of noticed displacements around structures, the relatively scarce notice of liquefaction in around, and the higher rate of strong ground defects for higher structures offers that ground strains joined with soil- structure interaction could have contributed to the triggering and intensity of ground defect [Sancio et al., 2002]. In this research, registered strong ground motion daatum were utilized to detect the soil magnification ratio in Duzce basin. Correspondance in basin were conducted by the help of the DEEPSOIL computer program which is a capacity of enabling one- dimonsion respons analysis. In these correspondances, the confining pressure dependent model [Ishibashi and Zhang 1993] was utilized for ground soil behavior response findings. The spectral hehaviour acquired for the profiles were compared with the original design spectrums offered in the Turkishquake Code (2007) and the Eurocode 8 (CEN 2004).

2.Geology of the Adapazarı Region Düzce Basin was formed by the activities of the North Anatolian Fault (NAF) and the Duzce basin is bounded by the active Gölyaka-Efteni-Beyköy Fault in the south and the Çilimli-Konuralp Fault in the north. The Çilimli-Konuralp Fault is relatively less active than the Gölyaka-Eftani-Beyköy Fault according to the historical and instrumemtal sources. These faults are part of the south and north segments of the NAF and they are the main brunches shaping the morphology of the region. The Düzce Plain has occured forming the mid-section of the basin presents a low inclined topography towards the southwest to Eftani Lake. The drainage network which has developed based on the morphology of the basin has NE-SW and E-W flows and leads to Melen creek. The Küçük Melen River and Asarsuyu Creek flows the surface waters of the basin into Lake Eftani. The Büyük Melen River subsequently discharges the waters of Lake Efteni to the Black Sea with a S-N flowing direction (Fig. 2). The hydrologic and morphologic properties in the basin are the results of the intense tectonic activity that controls the basin structure and overall slope of the plain.

100 Ali Ate , Latif. O. Ugur, Rifat Akbiyikli, Inan Keskin, Burak Ye il, Caner Demirdag

Fig.2. Geological map of the Duzce [MTA, 2002] The main area of the Duzce basin was occured with quaternary alluvial deposits containing gravelly and silty sand by the Asar creek and Küçük Melen creek (Fig.2). These sediments contain low-plasticity clay and silt. Quaternary formations are made of holocene alluvial deposits within different startum thicknesses, smooth gravel gradations, sand and silts .

3. Local Site Effects On Ground Motion Local site effects has an strongly impact all of the significant charecteristics, such as amplitude, frequency content, and duraton of strong ground motion. Their level of effect due to the geometry and properties of subsurface materails, on topography of the region, and on the charecteristics of the input motion [Kramer 1996]. Charecteristics of an earthquake are a role of fault mechanism, distance to the earthquake epicentre, geological structures and local soil conditions. The most important parameters of soil conditions are the elavation of a soil stratum on the bedrock, differences of the soil profile ans its charecteristics with depth, lateral geological heterogenity and surface topography [Birigen 2000]. If the thickness of the soft soil stratums above bedrock increases, prodominant periods of ground shift towards higher periods. More over, if shear wave velocity in soil layer decreases, dominants period of the soil shifts towards higher periods with higher amplifications. As a soil profile consists of various stratums, every stratums having various non-linear stress strain behaviour, the response of soil becomes more complicated. Thus, there are many investigators who have investigated the soil amplifications phenomenon utilizing real earthquake records; Ozgirgin [1977], Biringen [2000], Tezcan et al. [2002], Hasal and Iyısan [2004], Yalcınkaya [2004], Hasancebi and Ulusay [2006] and Kutanis and Ball [2006].


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There is no important influence factor on the dominant ground frequency from the point of view the the arrival angle of earthquake waves. But when only the arrival angle increases, a small reduction in amplification values is noticed. From previous studies from the point of view, it is usual to accept that vertical S-waves do not cautilize an important error [Yalçınlkaya 2004]. In the end, soil behaviour to be subjected to earthquake loading due to the soil layer thickness. Thus, ground response analysis where non linear behaviour of soils is taken into consideration are crucial for a safe earthquake-resistant design. In spite of the distance to the epicentre at Duzce was longer, the maximum horizontal peak ground acceleration was traced around this site. It can be occured due to the subsoil conditions.

4. Site Amplificationfactor in the Duzce Area Three different locations, namely Duzce centre, Duzce Eftani lake, and Gölyaka area were selected sites where is different. In thesse locations, buildings subjected to heavy damage during the August 17, 1999 Kocaeli and November 12, 1999 Duzce Earthquake. Anbazhagan and Sitharam [2009] offered that shear wave velocity of 700 ±60 m/s is consired to be the trace of engineering rock. Among these locations, Gölyaka area has the greatest depth to engineering bedrock at 180 m. Depths to base bedrock are 80 m for the Efteni Lake area, 60 m for the Duzce Centre location are recorded. Borehole logs acquired and shearwave velocities recorded profiles of these locations are presented in Fig. 3 and 4. These soil profiles are obtained from Municipality of Gölyaka and Duzce. Regarding to Gölyaka field works, study is performed in Golyaka in the scope of the palioseismological works. Detailed borehole logs are given in Fig. 3 that is cited from Alemdar [20017]’s master thesis. Shear waves of the soil layers were obtained from standard penetrations test (SPT) values utilizing emperical relations and performed surface geological studies.


Fig.3. Shear wave velocity V 30 map in Duzce For the selected locations, equivalent ground response analyses were conducted utilizing DEEPSOIL V.7 programme. This software is a graphical utilizer interface for DEEPSOIL V.7. It calculates ground response in a visco-elastic homogeneous and horizontally extending infinite system that is affected by shear waves advancing vertically [Ordonez,11]. This program is attributed to the repeated solution of the wave equations which are simulated for utilize in shortterm mobility, by the help of a Fourier transformation algorithm. Non-linear shear modulus and damping can be defined by effective deformation in each layer with a compatible shear modulus, and a repeated method is utilized with equivalent linear soil features to obtain damping values. Obtained spectral behaviour of selected locations were compared with the design spectrums submitted in the Turkish Earthquake Code (2007) and the Eurocode 8 (CEN 2004).


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Fig. 4. Shearwave velocities recorded profiles in Duzce The number of different shear modulus and reduction and damping curves to utilize in equivalent linear ground response analyses were present. Early models are utilized seperately for fine-grained and coarse-grained soils. But, further more last studies have shown a gradual trasition between non-plastic coarse and plastic-fine soils [Kramer 1996]. Sun et al. [1988] and Vucetic and Dobry [1991] declared that the shape of the modulus reduction curve is completely affected by the plasticity index while Iwasaki et al. [1978] and Kokusho [1980] propose that it is also affected by the effective confining stress, with G/Gmax increasing with increasing confining stress and plasticity index. whereas damping ratio decreaeses with increaesing confining stress and plasticity index. The effect of confining stress and plasticity index on modulus reduction and damping behavior were associated by Ishibashi and Zhang [1993], Darendeli [2001], Zhang et al. [2005]. To compare these studies, Darendeli [2001] has utilized a 120 m thick silty sand sand deposite with a stress- dependent shear wave velocity profile and they revealed that stress- dependent modulus reduction and damping ratio curves produced almost twice the peak ground acelaration that was considered by the generic curves, and larger spectral accelarations have been Found. Herewith, it is revealed that the utilize of both stress and plasticity index dependet models delivers more realistic ground response for the selected sites than traditional shear modulus and damping models. For this reason, the Ishibashi and Zhang [1993] model is prefered for ground response calculation fort his study. Figure 5 denotes %5 damped spectral acceleration which is yielded in Gölyaka.


Fig. 5. Ground surfaceacceleration spectrum yielded based on 1999 Duzce earthquake In this site, strong-ground motion data in Table 1 was utilized as bedrock earthquake motion [Peer 2007]. This strong ground motion was exerted to the base of the soil layers where engineering bedrock was given as Accelaration time history. Table 1. Strong ground motion data in analyses

Earthquake

Station

November 12 Meteoroloji Duzce Earthquake

Compound

90

Maximum Ground Accelaration (g) 0.453

Moment Magnitude

7.2

Acquired response spectra for selected areas were compared with the original design spectra of the stress-strain versus time (Fig. 6). Found response spectra for all sites are compared with the suggested design spectra of the stress-strain and %5 damping acceleration spectrum in Fig. 5 and 6.


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Fig.6. Stress strain versus time As it is shown from Fig. 6., the obtained surface response spectrum for 5 % damping exceeds the suggested design spectrum represented for the Z4 soil group between 0.2 and 0.5 s periods, that correspond to the predominant period of most of the typical residential buildings at Duzce. D soil type is assigned to soils which are soft-loose, thick alluvium stratums with shear wave velocity lower than 190 m/sec;when thickness of D type soil exceeds 10 m, It is graded as a Z4 group soil according to the Turkish Earthquake Code (2007). However, it is below the design spectrum recommended by the Eurocode 8 (CEN 2004) for soil class D. For Golyaka sites where the depths to engineering bedrock are significantly lower than that at Duzce centre sites, maximum spectral accelaration values are Found within the 0.05-0.2 s periods and these spectral Accelaration values exceed the recommended values in both the Turkish Earthquake Code (2007) and the Eurocode 8 (CEN 2004) (Fig.5,6). However, a 0.05-0.2 s period range

106 Ali Ate , Latif. O. Ugur, Rifat Akbiyikli, Inan Keskin, Burak Ye il, Caner Demirdag is lower than of most of the typical reinforced concrete residential buildings in Duzce city.

Fig.7. Peak ground horizontal acceleration with damping raio of %5 Seperately, obtained peak ground accelaration are also increased. Figure 7 shows an Accelaration- time graph acquired at the surface of the Golyaka soil profile under November 12, 1999 Duzce earthquake loading. Differences in the strong ground motion parameters are traced through the soil layers where seismic waves go through. Values of peak ground acceleration of ground motion diverge with depth. For soil profiles regarded in the analysis, the peak ground accelerations is reduced from the applied point to the surface, such as up to 60 m in the 90 m Golyaka profile, and up to 40 m in other profiles due to soil damping.


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Fig.8. Tranfer function of frequency The decrease of the peak ground acceleration values at these certain depths is due to bound to damping; continously increasing values above a certain depth shows influence of the surface waves (Fig.8). The transfer function defines how each frequency in the bedrock motion is amplified by the soil stratum. Figure 8 denotes an example transfer function, with larger site amplification acquired at a small frequency-high period due to weak and soft soil behaviour. During the main shock of the November 12, 1999 Duzce Earthquake, the largest recorded peak accelerations were likely not the largest which taken place. Especially, the record from Golyaka denotes peak acceleration of 0.81 g, larger than any peak recorded during the main shock. More over, during the November 12, 1999 Duzce Earthquake (Mw=7.2) Duzce event, at Bolu stations recorded 0.81 g East West [Çelebi et al.2000]. Tezcan et al. [2000] also expressed that the surface acceleration may be as large as 4-5 times those of base rock accelertions.

108 Ali Ate , Latif. O. Ugur, Rifat Akbiyikli, Inan Keskin, Burak Ye il, Caner Demirdag 5. Conclusions For the Duzce region, study site is situated on a thick alluvial squence, ground response alyses were conducted with the computer program pro shake 2.0 utilizing soil profiles from bore home at the site study that is drilled to describe soil magnification in the study area. While analysing, the November 12, 1999 Duzce Earthquake data was utilized to apply strong ground motion to soil profiles and differences in soil surface due to ground motion exerted on the sub stratum of the regarded soil profile. Spectral behaviour was compared with the design spectra of the Earthquake Code (2007) Z4 type and site class D, and Eurocode 8 (CEN 2004) type 1. Ground responseanalyses conducted in this research utilizing stress- dependent shear modulus and damoing ratio curves of Ishibashi and Zhand [1993] determine that the Found response spectra of the selected exceed the design spectra presented in the Turkish Earthquake Code (2007). The largest amplification for soil profiles is between 0.67 and 2.7 Hz in the transfer function while analysing. Acceleration of strong ground motions applied to the bottom of the soil profiles changes toward the ground surface. Due to the ground response analyses conducted utilizing the Duzce Earthquake registration, maximum peak ground acceleration is acquired at the Duzce Center. This site was significantly affected by the Duzce Earthquake. Some of the buildings at the Duzce center were damaged. It has been noticed for years that local site and soil conditions can affect the amplitudes, frequency and duration of seismic waves while they propagate throungh soil stratum around the ground surface. The November 12, 1999 Duzce Earthquake with a magnitude (Mw=7.2) struck the Marmara and Duzce regions in the North-Western area in Turkey. The earthquake cautilized considerable reasons and heavy damage to buildings. Among some cities influenced, Duzce in Marmara region significantly suffered the worst damage becautilize of the geotechnical effects and site response. REFERENCES [1]

Anbazhagan P, Sitharam TG (2009) Spatial variability of the weathered and engineering bedrock using multichannel analysis of surface wave survey. Pure appl Geophys 166(3):409–428.

[2]

Biringen E (2000) Soil amplification and case studies for clayey soils. Master thesis, Bogazici University, Istanbul.


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Cetin KO, Youd TL, Seed RB, Bray JD, Sancio R, Lettis W, Yilmaz MT, Durgunoglu HT (2002) Liquefaction-induced ground deformations at hotel Sapanca during Kocaeli (Izmit), Turkey earthquake. Soil Dyn Earthq Eng 22:1083–1092.

[4]

Darendeli MB (2001) Development of a new family of normalized modulus reduction and material damping curves. PhD., University of Texas at Austin, Austin.

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Firat S, Arman H, Kutanis M (2009) Assessment of liquefaction susceptibility of Adapazari city after 17th August, 1999 Marmara earthquake. Sci Res Essay 4(10):1012–1023.

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Gülen, L., Pınar, A., Kalafat, D., Özel, N., Horasan, G., Yılmazer, M., and I ıkara, AM., 2002. Surface fault breaks, aftershock distribution, and rupture process of the August 17, 1999 zmit, Turkey Earthquake. Bulletin of the Seismological Society of America, 92, 1, 230–244.

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Hasal ME, Iyisan R (2004) Effect of local soil properties on soil amplification: one and two dimensional behavior. In: 10th soil mechanics and foundation engineering congress, Istanbul, pp 343–352 (in Turkish).

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Hasancebi N, Ulusay R (2006) Evaluation of site amplification and site period using different methods for an earthquake-prone settlement in Western Turkey. Eng Geol 87:85–104.

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Ishibashi I, Zhang X (1993) Unified dynamic shear moduli and damping ratios of sand and clay. Soils Found 33(1):182–191.

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Ishibashi I, Zhang X (1993) Unified dynamic shear moduli and damping ratios of sand and clay. Soils Found 33(1):182–191.

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Iwasaki T, Tatsuoka F, Takagi Y (1978) Shear moduli of sands under cyclic torsional shear loading. Soils Found 18(1):32–56.

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Kokusho T (1980) Cyclic triaxial test of dynamic soil properties for wide strain range. Soils Found 20(2):45–60.

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Kramer SL (1996) Geotechnical earthquake engineering. Prentice Hall, Englewood Cliffs.

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Kutanis M, Bal IE (2006) Local soil conditions effect on structural damage distribution. In: 11th soil mechanics and foundation engineering congress, Trabzon, pp 99–113 (in Turkish).

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Maden Tetkik ve Arama Genel Müdürlü ü, Türkiye Jeoloji Haritaları, Ankara, Harita. 1/500 000. Maden Tetkik ve Arama Genel Müdürlü ü Yayınları, Ankara, 2002.

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Ordonez GA (2011) Shake2000 a computer program for the 1-D analysis of geotechnical engineering problems. User manual.

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Ozel O, Sasatani T (2004) A site effect study of the Adapazari basin, Turkey, from Strong- and Weak-motion data. J Seismolog 8(4):559–572.

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Ozgirgin F (1997) Case studies on soil amplification. Master thesis, Bogazici University, Istanbul.

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Peer (2007) Pacific earthquake research center, ground motion database. http://peer.berkeley.edu/smcat/search.html. Accessed 13 July 2007.

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Sancio RB, Bray JD, Stewart JP, Youd TL, Durgunoglu HT, Onalp A, Seed RB, Christensen C, Baturay MB, Karadayilar T (2002) Correlation between ground failure and soil conditions in Adapazari, Turkey. Soil Dyn Earthq Eng 22:1093– 1102.

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Tezcan SS, Kaya E, Bal IE, Ozdemir Z (2002) Seismic amplification at Avcilar, Istanbul. Eng Struct 24:661–667.

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Vucetic M, Dobry R (1991) Effect of soil plasticity on cyclic response. J Geotech Eng 117(1):89–107.

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Zhang J, Andrus RD, Juang H (2005) Normalized shear modulus and material damping ratio relationships. J Geotech Geoenviron Eng 131(4):453–464.

Jadwiga BIZON-GÓRECKA Jarosław GÓRECKI UTP University of Science and Technology, Bydgoszcz, Poland

RISK FACTORS FOR THE LIFE CYCLE OF THE CONSTRUCTION INVESTMENT PROJECT Keywords: Risk, Construction Project, Project Life Cycle

Abstract This work is a study of risk factors for a construction investment project. These projects are set in the formal and legal conditions specific for the construction industry. They are also involved in relationships with a number of stakeholders having an impact on their progress. Risk factors created during the life cycle of construction projects and their impact on the cost and time of investment implementation were described. To analyze the risk in the construction investment project, the method of review project documentation can we use, as well as the analysis and evaluation of documentation related to the preparation and implementation of the construction.

Introduction The term "risk" occurs in sciences about management usually in the analysis of decision-making processes; it refers to the characteristic of events which deprives (or limits) decisions and resulting action of effectiveness, advantage and economicality. The probability of such events occurring is a touchstone of risk [Bizon-Górecka, Górecki, 2013]. Risk we can see as probability of deviation (difference) between a plan and reality, or as posibility of some negative situation or a negative result which taking place [Pritchard, 2002]. Risk is the attribute of any venture. The risk in the project is connected with an incomplete predictability of the future conditions of its functioning. Therefore, for the need of a project, risk shall be defined as a product of likelihood of events and the consequences of its influence on the processes across the project [Pawlak, 2006]. No construction project is risk free [Renuka et al., 2014]. Academic and advisory institutions dealing with the issues of the effective management have recognized the principle role of risk management within this field. They have conducted a great number of educational activities for the management personnel from various economic sectors. Project risk management is the processes concerned with identifying, analyzing, and responding to project risk. Long life cycles of investment and construction projects, counted from the ideation, through its materialization, maintenance up to the phase of liquidation

Jadwiga Bizon-Górecka, Jarosław Górecki

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of erected buildings, make it necessary to take into account the philosophy of sustainable socio-economic development, harmonized with respect for the environment. Compliance with the principles of sustainable development in relation to construction means designing solutions for building objects (buildings and structures) and ways of their implementation in a manner that is friendly to people and their natural environment, taking into account the economic calculation [Rak, 2014]. A construction project is plagued with various risks in all the stages of the life cycle of the project. The stages of the life cycle of a construction project represents fig. 1 [Poło ski, 2011].

Pre-design works Projects 1

Implementation

2

Exploitation

Initial concept

...

3 Feasibility study

4 Project, arrangem ents

Preparation for implementation Implementation Start

5 6 Exploitation

...

The cycle of implementation Investment cycle

Fig. 1. Stages of the life cycle of a construction project 1 - an idea for a new investment, 2 - selection of a specific location variant and technical conditions for the construction of the facility, 3 - decision to continue work on preparing the planned object for implementation, 4 - obtaining a building permit or notification of construction works, 5 - final acceptance and possible removal reported defects, preparation of as-built documentation, transfer of the object to the investor, 6 - liquidation of a building object Source: elaborated on the basis of [Poło ski, 2011].

In each construction investment project, four stages of the investment process can be distinguished [Projekt celowy, 2004; Rogo a, 2014]: Phase A - preparation, the main products of which are documents establishing the general strategy for the implementation of the undertaking, including: – Project assumptions, specifying the purpose, scope, expected results, material program, forward plan and necessary resources of the undertaking,

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– Project management plan, specifying the way of proceeding for the implementation of the Project's assumptions; Phase B - design, the main products of which are technical documents describing the final product of the undertaking, including: – Drawings and technical descriptions necessary for proper performance of the final product of the undertaking, – Specifications of technical conditions of performance and acceptance of works that constitute the final product of the undertaking, – Object of works that constitute the final product of the undertaking; Phase C - construction, whose main products are: – A completed building object, being the final product of the undertaking, – Documentation containing tips for proper operation and maintenance of the facility; Phase D - use / operation, which does not lead to a specific product, but is associated with the assumed operation of the facility and its conservation, and often in further stages with modernization; as part of this phase, after the expiration of the warranty period final acceptance of the subject of the investment is made.

The specifics of the construction project The development of a new building structure, as well as its renovation, modernization or reconstruction of the original state requires taking a lot of conscious actions and decisions. The sequence of these coordinated actions and activities of a technical, technological, organizational, legal, financial, etc. nature, which lead to the implementation and exploitation of the planned construction project in a given time and costs, is called a construction investment process. On the other hand, the full life cycle of an investment is the time from the idea of investment implementation to the liquidation of an investment with the effects of its existence, e.g. for the environment [Poło ski, 2011, Plebankiewicz, 2006]. Construction is a broad field of the economy, covering the problems of shaping the natural environment of a man with long-term effects - often irreversible. The implementation of construction projects differs from production in other areas of management as it takes place under specific conditions. The following features of building production deserve to be emphasized [Bizon-Górecka, 2016]: - in the course of construction tasks, products (building objects) are permanently connected with the place where they are created, - interference in the natural environment in the course of construction processes implies a number of formal and legal requirements, - complexity of formal and legal issues, technological and organizational complexities as well as work safety hazards in the course of construction production make the engineering, technical and specialist staff have a number of

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requirements in terms of necessary powers, including the right to perform independent technical functions in construction, - the requirements of stakeholders of investment and construction projects stimulate globalization processes, - building construction processes are characterized by the need for a large number of diverse production resources, including a significant share of mass materials, - implementation of construction processes requires successive supply of production resources, which makes it necessary to jointly consider organizational logistics of production (ongoing logistics service of construction processes) and supply logistics (external supplies of raw materials, semi-finished products and prefabricates) and waste collection, - diversity of resource requirements for construction investment projects requires the use of diverse logistics systems, - technology of building processes realization stimulates their sensitivity to climatic conditions.

Tasks of a risk manager in the construction project A risk manager is a specialist on difficult situation in the construction project. His role in the project consists in providing dynamic answers to the following question: how to throw a security blanket around the project, enabling to take some risk in allowable limits? The risk manager in the project is especially responsible for monitoring the policy of risk, rooted in the objective of the project. First and foremost, he should deal with acquiring some knowledge about the future – should explain to employees what factors impact the success of the project. A risk manager realizes action referring to the issues of risk in the project, being the subject of risk management. Phenomena requiring an active attitude of managers, including among other things: the construction the policy of risk, its identification, measurement, taking action, control, are the subject of risk management. Mission and aims constitute the subject of risk management in the project. The degree of not fulfilling mission and not achieving aims of the project can be defined as being risk management in the project (in set periods of time). The loss of profit can be the consequence of risk management defined this way. Projects can insure themselves against the loss of profit, but also managers can insure themselves against civil responsibility for professional risk, connected with the management of the project (e.g. realizing managerial contracts). The risk of management in the project can also be considered individually, with reference to respective subsystems. For example, in quality management it is quality that is the subject of considerations of risk. The level of not fulfilling quality requirements quality can be a measure of risk in this area. The tasks of a risk manager especially include:


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- identification and collection of information about risk occurring in respective processes, and also an assessment of dangers to which the given project is exposed outside, - specification of the type events which can be the cause of damage and what impact will be on the financial condition of the project, - building scenarios for risk-taking, which was identified and, if possible, measured, i.e. the prevention of causes, and if the effects of dangerous events are impossible to avoid. A risk manager must make an up-to-date and detailed analysis of external and internal events, occurring in the project, which can pose a danger to others. Besides, he should specify the possibility of damage, i.e. the probability and size of loss. On the basis of proper evaluation of damage, the management of the project will be able to take appropriate measures aimed at lowering the degree of exposing the project to the loss of its assets. After identifying and exact evaluation of risk by the risk manager, the management must specify the means of prevention eliminating or lowering the assessed risk. Each time the selection of proper means should be the result of a detailed analysis of the effectiveness and costs of their introduction. One should take into account the fact that costs of limiting risk cannot be higher than the value of damage which might occur [Marcinkowski, Koper, 2008]. The function of a risk manager in the project is to serve management. He must take care of there being facilities for effective management in the conditions of ubiquitous risk. The major part of these facilities is, generally, the information system along with the data bank about phenomena from the past, serving the planning of the future. The structure of the system of planning, based on the analysis of the situation inside the project and danger from its surroundings, is an essential part of these facilities. The system of planning in risky conditions should be flexible and susceptible to signals. It cooperates in specifying the policy of the project based on the concept of risk. Risk manager and at least one of his specialists must know the specifics of the construction branch. Both its business problems, and technological methods applied in the project of internal processes.

Risk map in the construction project Risks encompassing the events that have an impact on project efficiency may be technical, economic as well as economic-technical. Among technical risks, the following may be distinguished: risk of technical appliances and technological lines reliability, product quality risk (encompassing product safety risk, risk of product use reliability), and others. Among economic risks, we may distinguish: risk of planning data reliability, market mechanisms risk, competitive position risk, financial risks (risk of offer price, risk of cost assessment, risk of financial liquidity, inflation risk, currency

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risk, credit standing risk, interest rate risk, stock market risk, warranty issuance risk, investment risk). Among economic-technical risks, the following may be distinguished: risk of engineering product design solutions engineering, risk of employees’ qualifications in the entire product creation process (connected with correlation: the level of qualification and salary costs), risk of synchronizing realisation processes, logistic risk, risk of technical progress. The mapping of risks, consisting on the risk of a functioning the project. The identification of risk factors is based on ideal recognition of processes, including technological principles. It should be also noted that some elements of risk are unpredictable. Therefore, the analysis of risk factors should be dynamic. In the classification of risk, the division may be made into: universal and specialized risk. The latter is a most common managers’ concern as it implies the threat of loss without any benefits and may imperil some project existence. The specification of project risks is presented on Fig.2. An exceptional type of risk is financial risk. It is generally comprehended as discrepancy between the expected and real business entity’s results, which is visible in the variance between the achieved results and their oscillation around the expected value. Some sort of regularity may be discerned in these oscillations, which with assumed level of likelihood (the level of trust), enable assessing the scope of results fluctuation.


CONSTRUCTION PROJECT RISK

TYPES OF LOSS

UNIVERSAL RISK

117

SPECIALIZED RISK

NORMAL CLASSES INDISPENSAB UNACCEPTAB

RISK OF HEALTH LOSS

PREPARATION OF INVESTMENT RISK RISK OF MARKET RESEARCH

RISk OF ECOLOGICAL LOSS

DESIGN OF CONSTRUCTION RISK LEGAL ACCORDANCE

RISK OF TECHNICAL PREDICTIONS

PROJECT SCOPE RISK TECHNOLOGY RISK

RISK OF ECONOMIC PROSPECTS

RISK OF INNOVATION

RISK OF FORMAL & LEGAL FORECAST

RISK OF HARMONISATI ON OF TIME FUNCTION PROCESSES

INVESTOR RISK

ECONOMIC CONDITIONS RISK

CONSTRUCTION RISK

EXSPLOITATION & LIQUIDATION OF BUILDING OBJECT COMPETITIVE POSITION RISK

RISK OF USE OF MACHINES & APPLIANCES QUALITY RISK

RISK OF ADMINISTRATIVE SERVICE

RISK OF SCHEDULE

TECHNICAL PROGRESS RISK

COST RISK

RISK OF LIQUIDATION PROCESS

LOGISTIC RISK DEPENDENCY ON SUPPLIERS & RECIPIENTS

MACROECONOMIC RISK

RISK OF PROPERTY OWNERS

RISK OF AFTER PRICE COST ASSESSMENT RISK FINANCIAL LIQUIDITY RISK FINANCIAL RISK

CREDIT STANDING RISK WARRANTY INSURANCE INVESTMENT RISK

Fig. 2. The specification of risks in the construction project Source: the own study

TYPES OF LOSS

ACCEPTABLE

118


The factors causing high economic risk in the project emerge within macroeconomic environment of project. Importantly, these factors stem from the project’s specificity and from its branch. Risk management is related to decision making as regards the risk affecting factors. In the project, risk management is facilitated by deducting the probability of loss of expected project efficiency. Basic stages of risk management are [Bizon-Górecka, 2007]: – risk identification, – risk estimation, – steering the risk, – funding the risk, – control of undertaken activities. Strategic aims of risk management, consistent with general aims of the construction project can be presented as follows: In terms of clients’ satisfaction: – goods and services consistent with the requirements set earlier, – goods safe in operation, – goods reliable in operation, – goods and services delivered in time. In terms of meeting owners’ expectations: – optimal profitability of production, – good image of the enterprise. In terms of employees’ satisfaction: – satisfaction with work, – satisfaction with workplace. In the sense of realizing social expectations: – production of goods and realization of services in an environmentally friendly way, – use of environmentally friendly technology and materials. Risk management should be considered to be the systematic process of management in the organization, being exposed to risk in terms of achieving set goals, referring to interests of owners, employees, public interest, safety of people, environmental factors, law, to name only a few. Risk management should be based on interdisciplinary knowledge and ontarget choices. Raising the awareness and competencies of employees through permanent training is the most important element for the system of risk management to function properly and seamlessly [Bizon-Górecka, Górecki, 2014]. The aim of control of the undertaken activities is to check the efficiency of activities aiming to limit the risk. The procedures of internal controls play a great role in controlling and limiting the project risk.


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Conclusions It is noticeable that the instruments used within the management field have developed into general management concepts, e.g. controlling, benchmarking, outsourcing, Total Quality Management (TQM), etc. Risk management merits a similar occurrence. The classification of risks according to the probability and overall result assessment of certain risks comprises the first step to systemize the issues of project risk. The next step is to analyse in detail the effects of risk and risk prevention. The systemic risk management in holistic terms constitutes the aspect of the whole functions of management is stands the chance of being the road map for ensuring the sense of safety of the project. Maximization of safety is the basic aim and direction of action connected with risk management. Safety should be understood to be a total level of safety measured by reverse probability of some damage occurring. Such safety is as a rule the highest when no action occurs. Determinants of the surrounding influencing the decision-making process of different character, and that is why only a universal tool enables to consider it properly supporting management. The analysis of the surroundings of project, referring to their situation in freemarket conditions, leads to many achievements of cognitive character, which can have application use. It also refers to marketing considerations. The theory of management by risk stands the chance of being a universal concept of the management of the project. To recapitulate, the introduction of the proper strategy of risk management in the project enables to: – raise awareness of the consequences of dangers, – focus attention on the system approach to risk management, – manage control effectively and centrally, – effectively process information about potential dangers, reduce long-term expenditure for the benefit of prospective advantages.

REFERENCES [1]

Bizon-Górecka J. (2007), Modelowanie struktury systemu zarz dzania ryzykiem przedsi biorstwie – uj cie holistyczne, TNOiK, Bydgoszcz, Poland.

[2]

Bizon-Górecka J., Górecki J. (2013), Ryzyko budowlanego projektu inwestycyjnego w perspektywie kosztów budowy, [in:] Przegl d Organizacji No 6/20013, p. 36-44.

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Bizon-Górecka J., Górecki J. (2014), Holistic recognition of risk as a condition of organization safety, [in:] Managing Organizations in Changing Environment, Chapter 20, edited by Andrzej Jaki, Tomasz Rojek, Cracow University of Economics, Cracow, p. 215-224.

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Marcinkowski R., Koper A. (2008), Ocena ryzyka czasu i kosztów w planowaniu produkcji budowlanej [in:] Przegl d Budowlany No 7-8/2008, p. 70-75.

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Pawlak M. (2006), Zarz dzanie projektami, Wydawnictwo Naukowe PWN SA, Warszawa.

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Pritchard C. L. (2002), Zarz dzanie ryzykiem w projektach. Teoria i praktyka, WIG – PRESS, Warszawa

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Plebankiewicz E. (2016), Koncepcja modelu predykcji rzeczywistych kosztów realizacji obiektów budowlanych [in:] Materiały Budowlane No 8/2016, p. 116119.

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Poło ski M. (ed.) (2011), Investment process and operation of construction works (in Polish), SGGW, Warsaw, Poland.

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Projekt celowy Nr 6T07 2004 C/6413 pt.: Krajowy system zarz dzania budowlanymi przedsi wzi ciami inwestycyjnymi finansowanymi z udziałem rodków publicznych i pomocowych Unii Europejskiej (KSZBPI).

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Rak A. (2014), Budowlane przedsi wzi cia inwestycyjne. rodowiskowe uwarunkowania przygotowania i realizacji, Wydawnictwo Naukowe PWN SA, Warszawa.

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Rogo a A. (2014), Wpływ zmian w dokumentacji na proces inwestycyjny, [in:] Przegl d Budowlany No 11/2014, p. 38-41.

Anna CHODOR Warsaw University of Technology Faculty of Building Services, Hydro and Environmental Engineering

PREFABRICATION OF BUILDING SERVICES

Keywords: prefabrication, modularization, building services, lean production, waste reduction

Abstract It is anticipated that prefabrication in construction industry will grow in popularity on a global scale in the near future. Analyzing specificity of the Polish market it can be predicted that the growth will be the most noticeable in residential and commercial buildings segments. Several studies have documented numerous benefits of prefabrication compared to traditional building methods. These include significant cost and time savings, enhanced productivity, increased quality of products and works, finally better environmental performance and reduced waste. The technology is gaining popularity not only in architecture and construction sectors, but as well in closely related fields, in particular building services. The paper presents proven applications of prefabrication in building services: prefabrication of repeatable building elements (horizontal pipes/ducts distribution, prefabricated wall modules and other), prefabrication of risers and shafts, prefabrication of technical rooms, modular bathrooms and toilets, finally preassembled or modular buildings including installed services. The shift from traditional construction methods to prefabrication requires significant changes in the construction process: design specific to off-site manufacturing, including BIM utilization, dedicated procurement and tendering strategy, well managed construction logistics, trainings of the staff to ensure proper education level. It is needed as well to overcome negative attitude towards prefabrication among the construction process participants, which may be quite often encountered according to the literature. This requires increasing the awareness of the prefabrication benefits and teaching all parties involved that prefabrication methodology is consistent with lean production principles – it efficiently reduces all types of waste, especially related to time, cost and material.

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1. Introduction Prefabrication is a construction technology, in which building elements are manufactured in a factory and afterwards are transported in whole or in parts into construction site, where they are connected. Above meaning can be found in the very word prefabrication, "pre" means the initial or earlier occurrence of something, whereas "fabrication" means production. Prefabrication is therefore a process of earlier production of elements that, after assembly, give a ready product, in this case a building structure1. According to Technavio report prefabrication is one of the most widely used modern methods of construction on the globe. Specialist estimate, that worldwide prefabricated construction market will increase at a compound annual growth rate of around 6,6% between 2016 and 20202. What is more, off-site manufacturing is in the centre of modern methods of construction (MMC) idea, which considers improvements in the construction technology aimed at reducing time, cost and waste of the process. APAC region is dominating prefabrication market globally due to dynamically urbanized economies like China, India or Indonesia and Europe is considered as the second market worldwide. Two European regions shall be mentioned here for their impact in the off-site technology growth, namely Great Briatin and Scandinavia. Great Britain was developing prefabrication strategy already in XVII century, when building its colonial power and since then played invaluable role in the technical development of the method. Scandinavia, on the other hand, should be distinguished for the use of prefabrication of wooden elements. In Poland prefabrication used to be commonly associated with the socalled “large slab”, a technology used widely in housing construction up to the ’90s of the last century. In social consciousness appeared kind of stigmatization of the method - it became a synonymous of extensive blocks areas, monotonous architecture and relatively low quality of workmanship. Poland was not isolated in these views - Australian publication3 lists negative perception of prefabricated housing and 1

Adamczewski, G. and Nicał, A., 2012. Wielkowymiarowe prefabrykowane elementy z betonu. In ynier budownictwa, 3, pp.46-53. 2 Smith, R.E., 2009, May. History of prefabrication: A cultural survey. In Third International Congress on Construction History. 3 Steinhardt, D.A., Manley, K. and Miller, W., 2013. Reshaping housing: the role of prefabricated systems.

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associations with provisional, temporary structures as one of the main factors ceasing the technology development. In recent years, however, can be noticed increasing interest in prefabricated technologies and at the same time a change in the way of perceiving prefabrication technology. In Poland, prefabrication is already commonly used in public, infrastructure and industrial construction4. A spectacular example of public investments was number of stadiums built for the football championships in 2012. Prefabricates are broadly utilised in the construction of multi-storey car parking, in factory and warehouse halls construction, and for infrastructural use in the construction of bridges, footbridges or underground passages. While in mentioned sectors has been noticed increased usage of prefabrication in recent years, in housing segment the trend is opposite, which can be described as a specific feature of the Polish market5. On the contrary, in Scandinavia, prefabrication is used mainly in multi-family and office housing and is utilised in round 80% of all facilities in this sector6. Analysing the trends in prefabrication usage in Europe and taking into account the forecasted global incensement in technology implementation, it can be expected that in upcoming years in Poland will be noticed not only increased share of prefabrication in the construction segment in general, but that the tendency to use prefabricated elements will be especially noticeable in the residential and office sectors. The housing market will be most likely driven also by the government program, “Mieszkanie Plus”, which is based on cheap construction using prefabricated solutions. 2. Prefabrication and sanitary installations Sanitary installations in buildings historically have origin in equipping particular buildings with imprecisely defined structure and form with the necessary installation elements. Such systems were created at the construction site and the implementation of prefabrication in case of 4

Szmigiera, E.D. and Woyciechowski, P.P., 2004. Niekonwencjonalne rozwi zania w prefabrykacji elementów z betonu. In Konferencja Dni Betonu. Tradycja i nowoczesno . Polski Cement. 5 Adamczewski, G. and Nicał, A., op. cit. 6 Adamczewski, G. and Woyciechowski, P.P., 2014. Wielkowymiarowe elementy prefabrykowane stosowane w budownictwie infrastrukturalnym. In ynier Budownictwa: miesi cznik Polskiej Izby In ynierów Budownictwa., (4).

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many unknowns in the building structure, would be impractical and basically impossible to carry through7. However, along with the technical development and improvement of the design process, already since World War II, several times appeared attempts to implement prefabricated sanitary installations in construction8. According to the British publication, the peak of prefabrication popularity took place in the 1960s, when the construction industry focused on industrial construction. Most of the contractors at that time had specialized teams that assembled system’s parts on the construction site before the final installation in the building structure. The fact of prior connection of selected elements before entering the building can be considered as the beginning of prefabrication in its present meaning. Next period of interest in prefabrication can be dated to the ‘90s, when many buildings with repeatable technologies, such as supermarkets, appeared on the market. Investors were trying to find a way to optimize the construction process, and in parallel were established number of subcontractor companies offering prefabrication services. Repeatability of installation systems is often mentioned in the literature as one of the main factors driving the prefabrication technology, but it should be emphasized that without the development of design techniques, especially without defining the building’s architecture and construction structure at a relatively early stage of investment, introduction of prefabrication in building services would be impractical and inefficient9. 2.1 Benefits of implementing prefabrication in building services Global interest in prefabrication, also in the building services sector, which can be observed in recent years is connected with numerous benefits to all participants of the investment process. The main benefits of precast technology are listed below: - price - one of the most fundamental advantages is the financial economy of the technology. Financial savings are usually at least in 10% range compared to traditional technology, although in the literature can be

7

Dwyer, T., 2016. Module 102: Offsite manufacture for building services. CIBSE Journal. [online] Available at https://www.cibsejournal.com/cpd/modules/2016-11-mod/ [Accesed 29.12.2017] 8 Marsh, C., 2003. Building services procurement. Routledge. p.82-84. 9 Dwyer, Y., op. cit.


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found estimates of cost reduction even up to 50%101112. Financial savings are basically a result of all advantages of the method mentioned next. Especially worth mentioning is the labor cost, which, depending on the market’s origin, ranges from 30% up to 50-60% of the total installation costs1314, thus significant acceleration of the installation process leads directly to measurable cost reductions. What is more, part of the labor moves from the construction site to the factories and working in stable factory conditions is considered to be not only more efficient, but also cheaper. In addition a British report15 can be quoted, showing that up to 40% of working hours on a construction site is wasted, - execution time - prefabrication technology significantly limits the installation's execution time. Estimates in the literature states that the installation time is limited by up to 30% -75% compared to traditional technology161718. Shortening time of completion to a large extent is a result of transferring of a large part of the works to the factory, which can be carried out simultaneously with the construction site works. Important is also reduction of errors at the execution stage, elimination of failures and re-works, which is the effect of a carefully planned design and production process in the factory. A spectacular example of the dynamics of prefabricated building construction is the construction of a hotel in

10

Fraser N., Race G.L., Kelly R., Winstanley A., Hancock P., 2015. An Offsite Guide for the Building and Engineering Services Sector, The Building and Services Association. 11

Jacobson M., Stannus W., Stavroulakis N., 2014. Fabricating the future, Ecolibrium, p.32-42. 12 Wilson, D.G., 1998. Prefabrication and preassembly: Applying the techniques to building engineering services. BSRIA. 13 Hui, S.C. and Or, G.K., 2005, July. Study of prefabricated building services components for residential buildings in Hong Kong. In Hubei-Hong Kong Joint Symp. 14 Pasquire, C., Gibb, A. and Bower, D., 2005. 'Lean'as an Antidote to Labour Cost Escalation on Complex Mechanical and Electrical Projects. In 13th International Group for Lean Construction Conference: Proceedings (p. 3). International Group on Lean Construction. 15 Egan, J., 1998. Rethinking construction: report of the construction task force on the scope for improving the quality and efficiency of UK construction. Department of the Environment, Transport and the Regions, London. 16

Fraser N., Race G.L., Kelly R., Winstanley A., Hancock P., op. cit. Jacobson M., Stannus W., Stavroulakis N., op. cit. 18 Wilson, D.G., op. cit. 17

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China - a building with 30 floors (16.700m2) was built out of prefabricated elements in 360 hours (15 days)19, - product quality - the effect of transferring a large part of works to the factory is as well the assurance of a sufficiently high quality of the product by working in a controlled and basically unchanged internal environment. What is more, it is possible to properly check and the quality of the products before the elements are being transported to the construction site, - improvement of construction management - optimization of the construction process is related to a lower number of workers at the construction site, reduction of stored materials and precise delivery schedules of ready-made elements from the factory. Because of frequent deliveries of large-size elements, it is needed to strictly keep to construction schedules and activities plans, including the use of cranes and specialist equipment. Specific construction logistics is one of the main challenges in the prefabrication implementation, but at the same time creates a very effective rigor of the process. This may be confirmed by a the report20 according to which only 34% of construction projects carried out in a traditional way are handed over according to the schedule, and 61% according to the assumed budget. In contrast, one of the main general contractors on the market claims that 97% of its construction sites using prefabrication fulfill the time and financial frames. Related aspect is the increase of works safety - transfer of a significant part of works to stable environment of factories significantly improves accident statistics of the whole process, - compactness of prefabricated solutions - extremely efficient use of available space in buildings is associated with the implementation of multi-branch cooperation at an early investment stage, careful planning of details and the use of advanced BIM or at least 3D tools. Prefabrication is often used when dealing with complicated parts of the installations, for example machine rooms, for their equipment and the distribution of pipes or ducts. Precise planning of all elements at the production stage in the factory allows, according to some manufacturers, to save as much as 40%

19

Myers, D., 2016. Construction economics: A new approach. Taylor & Francis.

20

Fraser N., Race G.L., Kelly R., Winstanley A., Hancock P., op. cit.


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-60% of the space for technical rooms21. Savings are also associated with a lower usage of materials, - environmental impact - prefabrication is considered to be cleaner technology compared to traditional building methods. To a large extent it is a consequence of construction waste reduction by the precise design of particular elements and the transfer of a significant part of production to a controlled factory environment. The activity of equipment on the construction site is also significantly reduced, what is more it is possible to limit by as much as 60%22 the movement of trucks transporting components to the construction site - one truck with ready prefabricated elements can be equivalent to 38 trucks delivering components in traditional technology. As a result, impact of construction on the environment, noise emission and pollution production is significantly limited. 2.2 BIM Properly prepared project documentation is one of the key elements enabling the proper implementation of prefabricated technology. Projects must be legible, transparent and provide an appropriate level of detail allowing production of elements in factory conditions. Virtual model of physical building components which is possible to obtain in BIM technology fits perfectly into the above requirements23. Some authors explicitly claim that in order to introduce prefabrication into the investment process, two basic elements must be provided: the use of BIM technology to create project documentation and the necessary optimization of the production process and product orders24. In the construction process using prefabrication, the emphasis on high-quality design is much greater than in the case of traditional technology. There is no room for lack of precision, uncoordinated elements and potential Moduls, 2017. Prefabricated Machine Room, Efficiency to real estate construction by enhancing machine room building. [online] Available at http://www.moduls.fi/365_upload/content_images/files/Moduls%20presentation%20EN G-HR.pdf [Accessed 30.12.2017] 22

Fraser N., Race G.L., Kelly R., Winstanley A., Hancock P., op. cit. Samarasinghe, T., Mendis, P., Ngo, T. and Fernando, W.J.B.S., 2015. BIM Software Framework for Prefabricated Construction: Case Study Demonstrating BIM Implementation on a Modular House. In 6th International Conference On Structural Engineering And Construction Management (pp. 154-162). 24 Dwyer, T., op. cit. 23

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collisions - it would be too time-consuming and expensive to rebuild products in the factory. BIM technology is used for prefabrication in the following aspects: - building a 3D model that visualizes all the elements of the installation, - ensuring that the model elements are of necessary accuracy and all needed information about them are stored in - impossible to obtain in 2D / CAD technology, - multi-branch coordination – within one model it is possible to coordinate architecture, construction and building services branches. Collaboration and introduction of multi-branch designers at the early stage of the project is recommended for both investments in the traditional way and using prefabrication. In this case, however, multidisciplinary working is crucial and basically enforced by the necessity to produce elements for particular branches in advance of the construction process itself, - generating material specifications, - input for the production of prefabricated elements in the factory - before the start of a factory production it is needed to prepare accurate enough model of elements being the subject of production. Most often BIM models from the designers need to be remodeled according to factory specifics, but still create a solid base for future work, - streamlining the logistics of the construction site – BIM can lead the project plan and create visualizations of elements deliveries and installation, including crane operations and tracing the modules routes through the facility to their final destination. It should be also mentioned that BIM standards for precast technology are being dynamically developed. The standards for BIM models used in the prefabrication field shall determine necessary information to be included in the model and ways of communication between participants of the investment process in order to efficiently exchange data on the model25. 2.3 Lean construction The concept of lean management, sometimes called "slim management" in Poland, was developed in the 90s of the last century based on the 25

Nawari, N.O., 2012. BIM standard in off-site construction. Journal of Architectural Engineering, 18(2), pp.107-113.


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production management system of the Toyota concern. The approach is a set of practices, tools and organizational solutions which primary task is to reduce production costs by eliminating activities not adding any value to the entire process, referred to in Japanese as "muda", or waste26. Numerous lean concept principles can be found in the construction industry and the idea of prefabrication: - searching for a way to maximize production efficiency, which can be considered as the basic commonality of both ideas, - reduction of waste from the production process - minimization of postproduction waste is one of the basic aims of lean management and also one of the main advantages of prefabrication technology, - the assembly process of prefabricated units is largely predictable and requires less man-hours of work. Also increasing the amount of predictable activities throughout the production process is consistent with the assumptions of lean management, - production of elements in the factory in advance to the construction drives better pre-planning process, more accurate design and "freezing" the design changes after starting production at the factory. This eliminates many issues traditionally encountered on the construction site caused by late changes in the project, often necessary to implement already on the site. Early optimization of the project and reduction of design changes throughout the process are consistent with the idea of lean management, - multidisciplinary coordination at an early design stage improves communication and information flow - lean management states that effective communication of all parties involved is necessary for the proper course of the entire process. 3. Typology of prefabricated sanitary installations There is wide range of possible applications of prefabrication in building services. Most typical usage examples are described below, categorized on the basis of the publication27. 3.1 Prefabrication of repeatable parts of the installation

26

Fuller, R.B., 1999. Your private sky: R. Buckminster Fuller: the art of design science. Springer Science & Business Media. 27 Wilson, D.G., op. cit.

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Prefabrication method is especially recommended for systems consisting of repeating units, elements and when multiple copies of the basic configuration of elements are being used. 3.1.1

Repetitive horizontal distributions

In the case of buildings with repetitive floors, especially office buildings, prefabrication is used in the installation of regularly repeated, basically identical services on particular floors. The fragments of the installations prepared off-site are usually distributions in the communication parts of buildings. In some cases it is possible to prepare in the factory the entire installation, for example for a heating and cooling system based on fourpipes fan coils, complicated due to large amount of components. In addition to office buildings, prefabricated solutions are used in public buildings or hospitals - an example shown in Fig. 1.

Fig. 1. Prefabricated horizontal distributions of sanitary installations for a hospital facility in Australia Source: Fredon Air, 2017. Horizontal services module assembly for Blacktown hospital. [online] Available at https://www.youtube.com/watch?v=kq6QH14srMw [Accessed 31.12.2017]

3.1.2

Prefabricated wall modules

Prefabricated wall modules is a solution dedicated especially for sanitary rooms in any type of buildings. The method is based on construction of complete sanitary walls including construction parts and sanitary assembly elements (most frequently toilet bowls, washbasins, urinals,


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bidets and other sanitary utensils) - examples are shown in Fig. 2. System walls afterwards are attached to the building walls and connected with footrests and cables. Walls are easy to assemble, flexible, tested in terms of fire protection and sound insulation - due to the significant reduction in construction time, the solution is especially useful when sanitary rooms in a building are frequently repeated. Wall modules are offered by the majority of leading producers of sanitary equipment. Although the method is most often applied for bathroom, toilet and toilet rooms, it can be successfully used for installation of heating, ventilation, air conditioning and other sanitary systems.

Fig. 2. Prefabricated TECE wall modules a) extended system of wall modules, b) transport to the construction site Source: TECE, 2017. Prefabricated wall modules.[online] Available at https://www.tece.com/en/prefabricated-wall-modules [Accessed 14.08.2017]

3.1.3

Other repetitive sanitary elements in buildings

In addition to the above-mentioned examples, repetitive solutions of smaller scale are also found in buildings. Mentioned here should be prefabricated heating manifolds, which are assembled in accordance with the investor's requirements in the factory and delivered to the site ready to be connected or prefabricated compact heat interface units for use in apartments. Residential heat interface units contain complete equipment for the distribution of heat and domestic hot water within the apartment. These solutions allow to save time during installation and configuration and to avoid many executive errors, for example related to the wiring of actuators. Examples of solutions are shown in Fig. 3.

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Fig. 3. a) prefabricated residential heat interface unit, b) prefabricated distributor heating manifold Source: a) Taconova, 2017. TacoTherm Dual Piko.[online] Available at http://www.taconova.com/pl/produkty/pv/technika-systemowa/5/tacotherm-dualpiko/401/ [Accessed 05.11.2017], b) UPONOR, 2017. Prefabrykowane szafki rozdzielaczy. [online] Available at https://www.uponor.pl/plpl/instalacje/produkty/rozwi%C4%85zania-prefabrykowane [Accessed 06.01.2018]

Worth mentioning are also modern solutions in the area of underfloor heating in buildings – studies are carried out on numerous improvements aimed at faster and easier installation of underfloor heating. On the market are available for some time dry floor heating systems based on prefabricated system boards made of foamed polystyrene or chipboard on which heating pipes are laid. These boards have prefabricated cuts making the board appropriately contoured for more simple assembly. The entire system is very compact and usually consists of four elements: the system board, radiating plate, heating tube and PE foil, an example shown in Fig. 4.


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Fig. 4. Floor heating using dry method a) detail, b) a cross-section through the floor Source: Roth, 2017. Metoda sucha TBS ogrzewania podłogowego. [online] Available at http://www.roth-polska.com/pl/Metoda-sucha-150.htm [Accessed 06.01.2018]

3.2 Prefabricated risers and shafts One of the most popular solutions using prefabricated technology is prefabrication of building services risers and shafts. In the literature can be found a number of examples of prefabrication of risers in high and high-rise buildings, for example the assembly of one of the largest blocks of multi-branch risers in Australia with a height of 10 floors, Fig. 5. Apart from a substantial acceleration in assembly time, one of the major advantages of the method is a significant increase of work safety level, by moving a greater part of the work at heights to the factories. The solution is applicable not only to high-rise buildings and it is often used in multistory residential buildings, hotels or dormitories.

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Fig. 5. Installation of one of the largest prefabricated, multi-branch risers units in Australia Source: Jacobson M., Stannus W., Stavroulakis N., 2014. Fabricating the future, Ecolibrium, p.32-42

In German-speaking countries common solution is to utilize prefabricated installation shafts designed as partition walls. Such a walls occur in many variants, the most popular are: walls replacing typical installation shafts and combining the function of shaft and a covering (Fig. 6a), walls to which installation accessories can be connected on both sides (Fig. 6b), walls installed in front of reinforced concrete structures (Fig. 6c).


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Fig. 6. Instabloc installation walls replacing typical shafts a) "SWS" type, b) "SWT" type, c) SWV type, d) wall transported to the construction site Source: Instabloc, 2017. Sanitary walls. [online] Available at http://www.instabloc.at/en/products/sanitary-walls.html [Accessed 20.08.2017]

3.3 Prefabrication of plant rooms and other technical rooms Prefabrication is a proven solution for complex installations, which execution on the construction site is labor-intensive, time consuming and what is more involves work on a small area, where precision is extremely important. An example of applications are all types of plant rooms, heat centers, boiler rooms, pumping stations and other sanitary technical rooms. Inherent in the off-site production process BIM technology or at least preparation of 3D models, is greatly functional for this type complex

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installation, which have to be designed in a very compact manner, but at the same time providing functionality, provision of service spaces, access to actuators, etc. Off-site production brings as well significant time reduction of the installation process. Examples of documentation in 2D and 3D for the off-site production of plant rooms as well as assembly of the installation are shown in Fig. 7.

Fig. 7. Prefabrication usage for plant room installation a) technical documentation of a plant room, b) assembly example in off-site environment Source: a) Constantair, 2017. Prefabricated Packaged Plantooms. [online] Available at http://www.constantair.co.uk/prefabricated-packaged-plantrooms/ [Accessed 06.01.2018], b) Edquarter, 2018. Turning up the heat. [online] Available at http://edquarter.com/Article/turning-up-the-heat [Accessed 06.01.2018]

3.4 Prefabrication of repeatable modules - sanitary facilities One of the more well-known examples of prefabrication usage in modern construction are prefabricated sanitary facilities, most often bathroom pods. In Japan, 80% of newly designed buildings are equipped with prefabricated bathrooms28, but the solution is gaining popularity all around the world, in Fig. 8a is presented factory in Poland specialized in 28

Modular Building Institute, 2018. Saving Time with Modular Bathroom Pods. [online] Available at http://www.modular.org/images/Bathroom%20Pods%20Whitepaper%20Dec16.pdf [Accessed 07.01.2018]


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production of prefabricated bathroom pods. Sanitary pods are made entirely in factories and arrive to the construction site fully equipped with sanitary facilities. The story of a prefabricated bathroom is related to the person of Buckminster Fuller, an American visionary of architecture who created a concept called "Dymaxion". The name of the concept has origin in combining the words dynamics, maximum and tension. From the 1930s, by “Dymaxion” Fuller was referring to a series of his innovative projects on the subject of future homes, one of them being a prefabricated house and a prototype of a self-sufficient unit not producing waste. But a Fuller's project, which was close to staring a mass production, was a prefabricated bathroom, designed inside “Dymaxion” house and also for individual installations in traditional construction. The project was even patented in 193829, Fig. 8b. Mass production finally was not started due to the resistance of sanitary installation engineers who blocked the production process, fearing for their own work30.

Fig. 8. Prefabricated bathroom modules a) prefabricated bathroom factory in Bolesławiec, b) Fuller's prefabricated bathroom from 1938 Source: a) Ready Bathroom, 2017. Galeria łazienek prefabrykowanych. [online] Available at http://readybathroom.eu/gallery.php [Accessed 15.08.2017], b) Fuller, R.B., 1999. Your private sky: R. Buckminster Fuller: the art of design science. Springer Science & Business Media.

30

Davies, C., 2005. The prefabricated home. Reaktion books. Fuller, R.B., op. cit.

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3.5 Integrated installations in prefabricated or modular buildings All the above-mentioned examples of the use of prefabricated installations can be successfully used in any type of construction, including the traditional one. However, when talking about a building constructed itself in a prefabricated technology, it should be considered what is the most optimal solution for the building services installation. A common situation is when the structure of a building is made of prefabricated building elements, that building services are installed already after finishing the construction stage, which involves the necessity of forging floors, walls, holes, etc., an example shown in Fig. 9a. Optimal solution is therefore off-site preparation of the distribution of sanitary and electric building services. Preparation of BIM models including architecture, structure and installation grids in the early stage of the process allows for proper multidisciplinary coordination, collisionfree installation and precise determination of drilling. An example of the BIM model prepared for the prefabricated residential complex of Tollare Torg in Sweden is shown in Fig.9b. Ready construction elements with integrated installations or specially prepared for their distribution allow quick assembling on the construction site and significantly eliminate execution errors. Worth mentioning is also modular construction concept, which can be described as the development of the idea of prefabricated bathrooms and which involves the assembly of buildings made of ready modules entirely prepared at the factory, equipped with all branch installations, partition walls, finished bathrooms, toilets and kitchens.


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Fig. 9. Sanitary installations in prefabricated buildings a) assembly of sanitary installations after completion of construction works b) BIM model of prefabricated structure with installation grid Source: a) Ecotech, 2017. Prefabricated house, from order to moving in. [online] Available at http://www.ecotech-bg.com/index.php/en/component/k2/item/55prefabricated-house-from-order-to-moving-in [Accessed 14.08.2017], b) Tollare Torg, 2017. [online] Available at https://www.tekla.com/bim-awards/tollare-torg# [Accessed 14.08.2017]

4. Barriers in prefabrication implementation Prefabrication in spite of all the above mentioned advantages is related with the necessity of changes in the investment process, with distinct approach to the purchasing and production mechanisms, and finally with a shift in the way of thinking about the construction process by all the parties involved. The most common barriers and difficulties in implementing prefabrication, which can be applied both for prefabrication as such and for off-site manufactured building services, are listed below: - Critical thinking about prefabrication, which should be treated as a more cultural or social than technical issue31. The issue is stronger in particular societies, for example in Poland and other post-communist countries due to associations with poor quality of construction dated to second half of the 20th century, and less significant in Scandinavian countries, where societies are more into pragmatic approach to 31

Steinhardt, D.A., Manley, K. and Miller, W., op. cit.

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technology. Negative associations with prefabrication appearing in societies can be regarded as a barrier especially for the development of prefabricated housing - if real estate developers will have problems with selling apartments produced in prefabrication technology, traditional method of construction will be the preferred one, - education and appropriate competences – prefabrication is associated with significant changes in the design, procurement and construction processes and therefore many participants involved, who are often accustomed to traditional roles, sharing responsibilities and methods, may show conservative attitude and oppose to potential changes32. Thus proper education of engineers and technicians is crucial, aiming to increase the openness to changes in the construction process, but also to provide the participants with the appropriate competences necessary to properly perform new tasks, - designing methods - production of prefabricated elements requires the use of at least three-dimensional models, and preference is given to models containing information about the building and its components (BIM). Although implementation of such a design methodology brings definite benefits to the entire process, it is often regarded as an implementation barrier due to expensive software licenses, lack of properly qualified staff and simply because many engineers are used to work in 2D. It is often a case, that the decision to involve prefabrication in the project is made too late in the process when the design is already very advanced. Changing the design outlines at such a stage practically results in redrawing the technical documentation cause unnecessary prolongation of the whole design process33. Therefore, it is crucial to implement prefabrication as early as possible in the design process, - influence of the investment process - in the classic investment process approach based on general contracting - design-tender-general contracting, selection of a general contractor is based on complete design documentation. In such process investor is forced to make decisions on design solutions at a very early stage, so after choosing a particular general contractor, design optimizations usually take place, and often 32

Lovell, H. and Smith, S.J., 2010. Agencement in housing markets: The case of the UK construction industry. Geoforum, 41(3), pp.457-468 Schoenborn, J., 2012. A case study approach to identifying the constraints and barriers to design innovation for modular construction (Doctoral dissertation, Virginia Tech).


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even entire building services systems needs to be redesigned. In the prefabrication industry commonly discussed are advantages of a different way of leading the investment process, which is design-build approach based on ordering both design and construction works from one specialized company. The method involves greater integration of the design and execution process, and closer collaboration of the entire team, including multi-branch engineers. Close cooperation of designers and engineers responsible for execution phase, ensure that solutions developed are usually optimal both in terms of design and execution aspects, and what is more costly and time-consuming late design optimizations and redesign work is eliminated, - production process and it’s preparation - organization of a production process in the case of precast technology is significantly different from traditional approach. It requires in advance availability of executive documentation of elements, preparation of material orders and creating an appropriate production schedule, taking into account assembly dates and production capacity of factories regarding both direct production activities and temporary storage needs34. What is more, attention needs to be given to transport and assembly works, transport of prefabricated elements from the factory to the construction site and the speed of assembly work on the construction site, much faster compared to traditional construction, all of listed features might be a difficulty for the parties involved. 5. Conclusions The article presented the outline of the prefabrication idea, discussed the advantages of its implementation in the sanitary field, presented the common areas of prefabrication utilization regarding building services, and finally listed the main barriers to technology implementation. Global market research indicates that the trend of increasing the prefabrication share in the construction market in the coming years will be continued. Due to the specific features of the Polish construction market, mainly excessively low participation of prefabrication in housing sector, and at the same time unmet housing needs of Poles, dynamic changes in technology of execution can be predicted, especially in the residential field. An important stimulus is also Adamczewski, G. and Woyciechowski, P.P., 2014. Prefabrykacja – jako , trwało , ró norodno . Zeszyt 1. Warszawa: Stowarzyszenie Producentów Betonów.

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the government program “Mieszkanie Plus”. In 2016, in the resolution regarding implementation of "National Housing Program", the government recognized an increase in the number of apartments as one of the basic objectives - by 2030, the number of apartments per one thousand inhabitants is to reach the European Union average, which means an increase from 363 to 435 flats per 1,000 people. One of methods used to achieve the intended goal is to use prefabricated solutions, as cheaper and faster to implement compared to traditional technology. Technological changes of prefabrication does not only concern architecture and construction fields, but also building services disciplines, including sanitary installations. Prefabricated and modular construction of buildings requires application of appropriate technological solutions in the field of sanitary installations, as the construction process is in a coherent whole and it is not possible to develop only selected parts. Potential lies also in prefabrication of building services installed in traditionally constructed buildings, mainly in off-site production of complicated or repetitive parts of the installation, like plant rooms and other technical rooms. Above mentioned usage of prefabrication takes place mainly in office buildings, public utilities, hotels, hospitals, industrial facilities. Described trends are reflected in latest conferences regarding the future of sanitary installations in buildings, emphasizing that one of the most important directions of sanitary sector’s development is prefabricated technology and integration with modular buildings. What might be interesting, in the American report35, in the list of most commonly used building elements made in prefabrication technology, the MEP systems (mechanical, electrical and pipe systems) are listed in second place, right after external walls elements. Without a doubt one of the most important factors stimulating the development of prefabrication technology is the financial aspect. Therefore, there is a need for reliable research comparing the costs of traditional and prefabricated construction. Although all off the sources confirm the reduction of costs due to prefabrication, currently available the estimates often show quite divergent results. There is also a lack of data on total cost reduction in the life cycle of the building, and not only during the execution phase. What is more, many researches on prefabrication concern the technological and material aspects of Construction, M.H., 2011. Prefabrication and modularization: increasing productivity in the construction industry. Smart Market Report.


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prefabrication, while much less attention is given to research on investor, intermediate participants of the process and final users preferences. In this context, research results36 conducted among architects, engineers and contractors may be quite surprising. Participants of the construction process familiar with the prefabrication technique asked about projects in which it the technology was finally abandoned for the main reasons listed: lack of available design documentation taking into account prefabrication and investors' reluctance to the method. Among the participants of the construction process not using prefabrication at all and explaining reasons for this fell arguments as above and in addition: lack of appropriate knowledge of this technology. The result of these studies indicate how important it is to educate all parties involved in the investment process about the benefits of prefabrication technology. Guidebooks and instructions on how to implement prefabrication and what are the changes for all the participants throughout the entire process can be of great help. Mentioned report also investigated the main reasons for using prefabrication - in the first place, especially for general contractors, was placed the increase of the whole process productivity, and in one of the last places was listed the investment requirements regarding prefabrication implementation. Increasing investors' awareness of the advantages offered by prefabrication technology and how its use significantly lowers the risks associated with completing time schedules and budget might therefore significantly increase the degree of the method usage on the market. Finally, remarkably important aspect of prefabricated technology is its minimized environmental impact compared to traditional technology. Environmental issues are priority in context of the implementation of the sustainable development strategy, reduction of energy consumption and reduction of the carbon footprint, implemented not only within the European Union, but also globally. Prefabrication, already taking into account the need to transport ready elements from the factory to the construction site, significantly limits the environmental impact of the entire production process. Production wastes are generated in the factory conditions in an incomparably smaller amount compared to traditional methods, and what is more, they can be controlled or even recycled. The amount of electricity consumed on the construction site is limited, the total amount of transports to the construction site is reduced 36

Ibidem

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as well. Environmental aspect should be especially highlighted at the central and governmental level, which should support environmentally friendly technologies - it could be possible to implement tax reliefs or other preferential settlement conditions for companies applying modern technologies, like prefabrication. REFERENCES [1]

Adamczewski, G. and Nicał, A., 2012. Wielkowymiarowe prefabrykowane elementy z betonu. In ynier budownictwa, 3, pp.46-53.

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Adamczewski, G. and Woyciechowski, P.P., 2014. Prefabrykacja – jako , trwało , ró norodno . Zeszyt 1. Warszawa: Stowarzyszenie Producentów Betonów.

[3]

Adamczewski, G. and Woyciechowski, P.P., 2014. Wielkowymiarowe elementy prefabrykowane stosowane w budownictwie infrastrukturalnym. In ynier Budownictwa: miesi cznik Polskiej Izby In ynierów Budownictwa., (4).

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Construction, M.H., 2011. Prefabrication and modularization: increasing productivity in the construction industry. Smart Market Report.

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Davies, C., 2005. The prefabricated home. Reaktion books.

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Dwyer, T., 2016. Module 102: Offsite manufacture for building services. CIBSE Journal. [online] Available at https://www.cibsejournal.com/cpd/modules/201611-mod/ [Accesed 29.12.2017]

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Egan, J., 1998. Rethinking construction: report of the construction task force on the scope for improving the quality and efficiency of UK construction. Department of the Environment, Transport and the Regions, London.

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Fraser N., Race G.L., Kelly R., Winstanley A., Hancock P., 2015. An Offsite Guide for the Building and Engineering Services Sector, The Building and Services Association.

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Fuller, R.B., 1999. Your private sky: R. Buckminster Fuller: the art of design science. Springer Science & Business Media.

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Hui, S.C. and Or, G.K., 2005, July. Study of prefabricated building services components for residential buildings in Hong Kong. In Hubei-Hong Kong Joint Symp.

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Jacobson M., Stannus W., Stavroulakis N., 2014. Fabricating the future, Ecolibrium, p.32-42.

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Kozlovská, M., 2011. Modern methods of construction vs. construction waste. International Multidisciplinary Scientific GeoConference: SGEM: Surveying Geology & mining Ecology Management, 3, p.483.


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Lovell, H. and Smith, S.J., 2010. Agencement in housing markets: The case of the UK construction industry. Geoforum, 41(3), pp.457-468.

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Marsh, C., 2003. Building services procurement. Routledge. p.82-84.

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Modular Building Institute, 2018. Saving Time with Modular Bathroom Pods. [online] Available at http://www.modular.org/images/Bathroom%20Pods%20Whitepaper%20Dec16.p df [Accessed 07.01.2018]

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Moduls, 2017. Prefabricated Machine Room, Efficiency to real estate construction by enhancing machine room building. [online] Available at http://www.moduls.fi/365_upload/content_images/files/Moduls%20presentation %20ENG-HR.pdf [Accessed 30.12.2017]

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Myers, D., 2016. Construction economics: A new approach. Taylor & Francis.

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Nawari, N.O., 2012. BIM standard in off-site construction. Journal of Architectural Engineering, 18(2), pp.107-113.

[19]

Paprocki, A., Szewczyk S., 1976. Prefabrykacja budowlana. Cz Biała: Wydawnictwo Szkolne i Pedagogiczne, p.7.

[20]

Pasquire, C., Gibb, A. and Bower, D., 2005. 'Lean'as an Antidote to Labour Cost Escalation on Complex Mechanical and Electrical Projects. In 13th International Group for Lean Construction Conference: Proceedings (p. 3). International Group on Lean Construction.

[21]

Samarasinghe, T., Mendis, P., Ngo, T. and Fernando, W.J.B.S., 2015. BIM Software Framework for Prefabricated Construction: Case Study Demonstrating BIM Implementation on a Modular House. In 6th International Conference On Structural Engineering And Construction Management (pp. 154-162).

[22]

Schoenborn, J., 2012. A case study approach to identifying the constraints and barriers to design innovation for modular construction (Doctoral dissertation, Virginia Tech).

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Smith, R.E., 2009, May. History of prefabrication: A cultural survey. In Third International Congress on Construction History.

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Steinhardt, D.A., Manley, K. and Miller, W., 2013. Reshaping housing: the role of prefabricated systems.

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Szmigiera, E.D. and Woyciechowski, P.P., 2004. Niekonwencjonalne rozwi zania w prefabrykacji elementów z betonu. In Konferencja Dni Betonu. Tradycja i nowoczesno . Polski Cement.

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Technavio, 2016. Report: Global Prefabricated Construction Market 2016-2020. [online] Available at https://www.technavio.com/report/global-constructionprefabricated-market. [Accessed 21.04.2018]

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Wilson, D.G., 1998. Prefabrication and preassembly: Applying the techniques to building engineering services. BSRIA.

I. Bielsko

Ahmed ELKHERBAWY1 Jose-Antonio LOZANO2 Gonzalo RAMOS1 Jose TURMO1 1

Universitat Politècnica de Catalunya, BarcelonaTECH, 2 University of Castilla-La Mancha 1, 2 Faculty of Engineering

LEAN CONSTRUCTION IN ROAD PROJECTS

Keywords: Management, Lean Construction, Road projects, Waste, Last Planner System.

Abstract By far civil engineering represents one of the fields with lower productivity. This fact can be explained by a number of reasons, such as the lack of standardization in their projects, insufficient attention to building details or inadequate automation. The Lean approach stands as a management method aiming to reduce all project wastes leading to higher productivities and lower costs. Since the introduction of this concept after WWII, this has been successfully implemented into a number of disciplines, such as industrial or the aerospace engineering. Nevertheless, because of its peculiarities, the application to the civil engineering field is not as straightforward. Among the civil engineering, the road projects stand as one of the most economically and environmentally costly. For this reason, special attention to increase the productivity and to reduce the cost of this kind of projects is required. To fill this gap, this paper reviews the current state of the art of the application of the lean approach for the management of road projects. This review will present the main contributions of this approach in the road management field to encourage scholars and practitioners the use of this methodology.

1. INTRODUCTION Construction industry is considered one of the most important and critical industries in which work never stops; houses, roads, bridges and factories are and will remain essential. However, contrary to other industries, the construction field has been suffering from low productivity over the last decades, (Pettersen, 2017). This goes back to the many problems and challenges faced by the industry, such as cost overruns, schedule durations behind the estimated time, poor quality of the finished works, which lead to rework and repairing in addition to workers’ accidents and environmental obstacles that

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might arise. Such complications eventually result in conflict between projects stakeholders (Rodewohl, 2014).

2. LEAN CONCEPT One of the main reasons behind these problems is that some tools and methods applied in the traditional project management approach have been implemented without any updates for the last seven decades. Adaptation of tools from the manufacturing industry has been taking place to fit implementation to the construction industry. Lean Construction (LC) is one of these tools, which was initially invented by Toyota Production System. The Lean concept was named as Lean Production (LP): by applying Lean concept to Toyota Production System, products are delivered with higher quality and productivity opposite to the case before (Pettersen, 2017).

2.1 History for Lean concept The history of developing Toyota Production System (TPS) began in the 1950s. This system was not developed because of the lower productivity or poor quality, but because it was regarded as a need. After WWII, Japan started to rebuild their infrastructure sector as whole. However, there were two challenges, which needed to be addressed first. First, Japan had a few amount of domestic resources, and second there was a restricted access to foreign trade options. Due to these two challenges, the country needed to use the domestic resources wisely. Toyota Motor Company recognized that it was necessary to develop a different approach, which required decreasing the number of unsold products due to defects problems or because they did not match the customers' requirements. From this point, the approach was shifted from “manufacture push” to “customer pull” (Kahlen and Patel, 2011).

2.2 Lean concept principles and tools Figure 1 shows the five lean principles; (Rodewohl, 2014) a) Value; understand the customer requirements and needs. b) Value Stream Mapping (VSM); has three main steps: make the current state map, determine the non-adding value activities and make modifications by applying the future state map. c) Flow; focuses on removing the non-adding value activities. d) Pull; more specifically focuses on delivering the material on time not before or after; concept of Just In Time (JIT). e) Perfection; focuses on the continuous improvement and continuous application of the previous steps.

Lean constructıon ın road projects

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Fig. 1. The five Lean Principles Source: The presence of Lean Construction principles in Norways transport infrastructure projects, Norwegian University of Science and Technology, 2014.

Lean Production (LP) has many tools to be applied in their right sequences; some of these tools can be adapted to the construction industry. Lean Construction (LC) tools are mainly: (Gaio and Cachadinha, 2011; Pettersen, 2017; Tezel, et al., 2016a; 2016b; Jang and Kim, 2007; Tezel and Aziz, 2016) a) Last Planner System (LPS); which relates to production planning and control tools and focuses on improving workflow reliability. b) Just In Time (JIT); delivering the material on time not before or after. c) 5S; is a housekeeping methodology. d) Total Productive Maintenance (TPM); controls the maintenance of equipment. e) Target Value Design (TVD); relevant to the clients´ value, minimizing wastes and satisfying or maybe exceeding the client’s expectations. f) Visual Management (VM); is a visual information management tool.

2.3 Lean concept duration activities and wastes As shown by Kivistö, Ohlsson and Jacobsson, (2013), there are three types of time duration for any activity. First type is Value Adding activity (VA) which relates to the actual time needed to finish an activity, while the other two are named as wastes because they do not add value to the activity. First type of wastes that are essentially occurring; in other studies, this can be referred to as Essential Non-Value Adding activities (ENVA). Second is the wastes that are not essentially occurring and can be removed. Kivistö, Ohlsson and Jacobsson, (2013) presented eight types of wastes that can occur in any construction project. Heyl, (2015) explained that the reason of the

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waste existence in road construction projects is related to the “unreliable schedules, insufficient supply and troubleshooting”1, besides the trucks having actual work time 50% of their cycle time. As displayed in Figure 3, the eight types of wastes are: (Kivistö, Ohlsson and Jacobsson, 2013): a) Over-production; is producing too much of the product. b) Waiting; which occurs in case the labour or the machines are waiting for something to occur before they could accomplish their work, for example waiting for the shop drawing for an activity. c) Unnecessary motions; is making a useless motion (of labour) within an activity (process). d) Transportation; making a useless motion (of machine) in the middle of an activity (process). This may lead to the damage of the material or the final product e) Inappropriate processing; using the inappropriate machine within the activity, which can lead to accomplishing the work in an incorrect manner or even to damages. f) Inventory; includes three parts raw material, work in progress and finished goods. Increase in this type of wastes leads to increase in handling and increase in the costs of the material; being damaged in storage area. g) Defects; relates to rework in the activity. h) Unused human potential; engaging the inappropriate workers within the activity; they will not add benefit or value in contrast to the appropriate workers.

1

Von Heyl, J., 2015. LEAN SIMULATION IN ROAD CONSTRUCTION: TEACHING OF BASIC LEAN PRINCIPALS. In Proceedings of 23rd Annual Conference of the Int’l. Group for Lean Construction. Perth. Australia (pp. 403-412).


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Fig. 2. The eighth types of wastes Source: own research adapted from Expanding Lean into Transportation Infrastructure Construction, Chalmers University of Technology, 2013.

2.4 Lean concept benefits The main goal of Lean Production (LP) is to deliver the final product with the best quality, in the shortest time with an empty warehouse. This concept can be better reflected through these points, (Farrar, AbouRizk and Mao, 2004): a) Remove the activities that add no value to the final product; Non-Value Adding activities (NVA). b) Apply the concept of pull, which seeks to deliver the material on time not before or after its need. c) Reduce the variability changes by determining the uncertainties while creating the final product. The reasons and benefits of the below three Visual Management (VM) tools are: (Tezel, et al., 2016a) •

•

Visual performance system; to monitor the teams’ performance in the construction project, also to increase the efficiency of the meetings by solving the problems. Visual specification/indicator; to increase the coordination and transparency during the project’s closure and decrease the non-addedvalue activities, because many contractors face penalties of the number of closure they incurred by their contracts.

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Visual control; is the project control board that has data from Last Planner System (LPS) on the board.

Rodewohl, (2014) summarized the main benefits that Toyota Production System (TPS) gained after inventing Lean Production (LP): a) No reworks were required and defects almost completely disappeared. b) The customers’ trust increased. c) The production engineering costs were decreased, so Toyota offered more types of cars. d) The relationship between Toyota and its customers became better, because there was better understand of their requirements and needs. The concept of pull system was born. Fullalove (2013) explained that the Highway Agency (HA) Lean Division in the UK was established in 2009. After this establishment, there has been successful implementation of Lean concept in some major road projects, such as the M6 extension from Carlisle to Guards Mill. One of the most important benefits is related to cost saving; around £4.7Million in the last project compared to the one before it. The UK Highway Agency (HA) approved to apply Lean concept in internal process and procedures. Moreover, before using Lean concept, the Highway Agency (HA) spent £1Billion on capital projects and more than £1.5Billion on maintenance. These were payed to repair the road projects.

2.5 Lean Construction requirements There are general requirements that should be respected to have successful implementation of Lean Construction (Rodewohl, 2014): a) Every project member carries the whole responsibility for the project. b) Project team will solve uncertainties and defects. c) The first priority is the project's success. d) Good relations and close collaboration between project members. e) The whole team searches for their improvements and as every project member responsible for the whole project so the successful for the project is the successful for project members. Further, Gaio and Cachadinha, (2011) demonstrated specific requirements to have successful implementation of Lean Construction specifically in road projects: a) Understand and determine the sequence of tasks. b) Gather all the activities that are non-adding value. c) Determine the duration of the tasks. d) Determine the present state of the project.


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e) Determine which activities need improvement for the future state. Focus on activities, which require the highest improvement. f) Decrease or remove any activity that is non-adding value (not essential activities). g) Apply the concept of Just In Time (JIT), to deliver the material on time not before or after (Pull system). h) Determine the future state of the project. i) Determine how to improve the durations of the adding value activities. j) Add buffer to face the uncertainty and variability of the activities.

2.6 Lean Construction barriers In contrast to Lean Production (LP), Lean Construction is still being applied in few countries around the world. The main barrier to applying Lean concept to the construction industry or the reason why it could be applied in a wrong way has been the site management and workers' lack of awareness of this tool (Gaio and Cachadinha, 2011; Heyl, 2015). Farrar, AbouRizk and Mao, (2004), presented another reason for not applying Lean concept to the construction industry; many construction parties feel hesitate of applying a new management tool (Lean Construction) to their projects, since these projects' cost can reach multi-million dollars. The purpose of Tezel, et al., (2016b) is to determine the drivers and barriers for implementing the concept of Visual Management (VM), and also to identify the opportunities of applying the concept of Visual Management (VM) in the future England’s highways construction supply chain. These points were identified by sites observations of five highways construction projects in England. The determined data were obtained by conducting interviews, focus group discussions and observation during the site observations for the case studies. The barriers that emerged challenging the implementation of Visual Management (VM) from the five case studies and focus group discussions mainly include: a) Lack of awareness of Visual Management (VM). b) Limited view to the visual performance board. c) Lack of personal driving of Visual Management (VM) and Lean Construction (LC) in highway projects. d) Limited communication with operational staff to drive Visual Management (VM) further.

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3. APPLICATION FOR LEAN CONCEPT IN ROAD PROJECTS Many scholars used lean techniques to achieve improvements in road projects (Tezel, Koskela and Aziz, 2017; Pettersen, 2017; Tezel, et al., 2016a; 2016b; Daniel, Pasquire and Dickens, 2016; Tezel and Aziz, 2016; Heyl, 2015; Rodewohl, 2014; Kivistö, Ohlsson and Jacobsson, 2013: Fullalove, 2013, Gaio and Cachadinha, 2011, Kahlen and Patel, 2011; Jang and Kim, 2007; Farrar, AbouRizk and Mao, 2004). These studies used different Lean tools; Tezel, Koskela and Aziz, (2017) focused on determining the condition of Lean Construction in Small-Medium Sized Enterprises (SMEs) in England’s Highway (Current condition of Lean Construction) and finding the way to spread the Lean concept to England’s Highway supply chain by using survey to experts (Future condition of Lean Construction). According to the current condition of Lean Construction in Small-Medium Sized Enterprises as demonstrated in the literature, there is lack of resources, which affect the deployment of Lean concept; clients’ traditional commercial teams could be a barrier for Lean concept and training for Lean covers the basics knowledge. Regarding the anticipated future condition of Lean Construction Small-Medium Sized Enterprises, Current tendering mechanism will support the creativity of Lean concept and share the risk, besides applying more training sessions for Lean concept, engaging with Small-Medium Sized Enterprises and determining the number of resources needed. Pettersen, (2017) conducted a qualitative research to investigate the current situation, the possibility and the barriers of applying Lean concept to infrastructure projects, especially road projects. The study relied on interviews to experts from three case studies; the interviews and literature review are the main sources of information. The study results show that two of the three case studies were using Lean concept, however the researcher did not have full answer if there was any challenge to apply Lean concept in the Norwegian road construction projects. The author did not see any challenges related to transport infrastructure and implementation of Lean Construction compared to other construction sectors, such as building construction, from client’s perspective. Tezel, et al., (2016a) sought to identify the benefits that can result from Visual Management (VM) tools such as 5S (which will be explained more in details below), visual performance system, visual specification/indicator and visual control. The scholars used two infrastructure projects to achieve the study’s aim. There were benefits on the savings of time after applying the concept of 5S, (Table 1). Before using Visual control board on project two, Planned Percentage Complete (PPC) values were about 55% to 60%, but after including it, PPC values reached 85%. PPC is the percentage of the total number finished tasks over the total number of planned tasks.


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Table 1. Time savings after implementing 5S

Source: Benefits of visual management in the transportation sector, Conf. of the Int’l. Group for Lean Construction, 2016.

The implementation of Tezel, et al., (2016b) based on the five case studies and focus group discussions include: a) Increasing the attention given to Lean Construction (LC) and its techniques in the UK. b) Highways England’s commitment to affect contractors’ decisions. c) Visual Management (VM) can help decrease operational waste and increase work coordination. Future opportunities for Visual Management (VM) implementation in England’s highway construction projects based on the five case studies, researchers’ observations and focus group discussions include: a) 1st case study: 1. Boards on the site with critical quality steps and schedule expectations. 2. Determination of the reasons behind cost errors/mistakes. nd b) 2 case study: 1. Having boards with Last Planner System (LPS) and performance boards. 2. Visualization of method statements. 3. Visualization of root cause analysis and continuous improvement process.

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c) 3rd case study: 1. Standardised visual performance board. 2. Visualization of continuous improvement process. th d) 4 case study: 1. Visual boards for costs and schedules. 2. Simplifying the formats of the routine reports from clients and senior management that are shared with the workforce. th e) 5 case study: 1. Apply 5S technique. 2. Managers collect more Visual Management (VM) ideas from on-site workers. Focus group discussions findings: a) b) c) d)

Extending Visual Management (VM) to have more performance boards. Should have a visual system. The data should be tackled before information visualisation. In Visual Management (VM), it is important to show the ultimate project goals and company vision.

Researchers’ observations:

1. Application of 5S in different sectors of the projects. 2. Visual standard operating sheets on mobile boards or vans. 3. Visual control board linking Last Planner System with site teams. 4. Extended use of cloud Building Information Modelling, (BIM) for better information visualization among mobile work teams. Daniel, Pasquire and Dickens, (2016) seek to determine the factors that influence Last Planner System (LPS) implementation on Joint Venture (JV) highway projects in the UK. The main reason of resorting to Joint Venture projects is that the project partner (for example: contractor) wants to share the risk, utilise skill, knowledge and resources with others. The author reached his target of the study by studying two case studies for twelve months, both with Joint Venture contracts. The methodology used includes interviews, document analysis and site observation. The data was collected from these projects by conducting interviews with a total of 21 interviewees. The researcher found that the following factors are essential to successfully implement Last Planner System (LPS): a) Reduced batch size; it was observed that dividing the batch supports the concept of Last Planner System. The first case study was batched to three sections while the second one was batched to two sections. Batch means the working area.


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b) Inclusion of Last Planner System practice in the contract; for both case studies, it was found that Last Planner System (LPS) is included in the contracts between client, contractor and subcontractors. c) Use of collaborative form of contract and long-term relationship focus; both projects had JV contracts. The study stated that in this type of contract, it is better to share expectations among the teams of the project, which helps improve the general behaviour during the project. d) Training and creation of awareness; the majority of the respondents stated that the subcontractors and main contractors need more training. e) Appointment of facilitators and lean champions; from the conducted interviews many respondents stated that the appointment of facilitators and lean champions is essential for the improvement of Last Planner System (LPS) in JV projects. f) Provision of physical space and co-location of the team; it was revealed that the availability of room for planning, controlling and co-location between teams is essential. The physical space was needed to have a visual board for the project, also it was seen that these rooms were close to the workspace. g) Team integration and less parent company identity; the teams should ignore their parent company identity to create their responsibilities on the project. There is a strategy to share their emails, spaces, offices and every facility on the JV project. By doing this the teams will ignore their main company´s identity and work under the JV identity. The study identified four blockers of Last Planner System (LPS), which could potentially hinder its implementation in JV contracts: a) b) c) d)

Poor promising. Culture of old thinking and attitude among middle managers. Lack of discipline and trust. Resistance through procurement.

From the identified barriers and blockers of Last Planner System (LPS), the researcher concluded that human behaviours are the major problem for implementing Last Planner System (LPS). Tezel and Aziz, (2016) after making ten visits to five different road (Highway) projects, managed to determine the benefits of 5S and implemented it on one of the highway construction projects (pilot project). It is important to mention that as shown in Figure 4,5S refers to: a) b) c) d)

Sorting. Setting-in-order. Shining. Standardizing.

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e) Sustaining.

Fig. 3. 5S explanation Source: Visual management/visual controls implementation pilot: 5S in Highways Construction and Maintenance, University of Salford Manchester, 2016.

After the implementation of 5S on the pilot project, from Table 2 the amount of time-savings needed to get every item from the warehouse by skilled and unskilled labours can be determined.


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Table 2. Comparison between before and after 5S application on the pilot project

Source: Visual management/visual controls implementation pilot: 5S in Highways Construction and Maintenance, University of Salford Manchester, 2016.

Heyl, (2015) presented a simulation game for road projects that was done twice; first using the traditional approach and then by using Lean concept. There is a comparison between the results, which were obtained from the two simulations. The following formula is used to calculate the required number of trucks needed:

In this equation, P refers to Performance finisher, T: Circulation time, S: Safety factor and C: Capacity of truck (game roles are shown in Table 3). By decreasing the number of trucks used and improving the reliability of the supply, there was an improvement in the efficiency of the resources used. The results of the two simulations (Round 1 and 2) game are shown in Figure 5.

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Table 3. Game Roles

Source: LEAN SIMULATION IN ROAD CONSTRUCTION: TEACHING OF BASIC LEAN PRINCIPALS. In Proceedings of 23rd Annual Conference of the Int’l. Group for Lean Construction, 2015.

Fig. 4. Results of the simulation games Source: LEAN SIMULATION IN ROAD CONSTRUCTION: TEACHING OF BASIC LEAN PRINCIPALS. In Proceedings of 23rd Annual Conference of the Int’l. Group for Lean Construction, 2015.

Rodewohl, (2014) explained the requirements to apply the Lean concept to infrastructure projects; the process to integrate the project team into different project phases and the responsibility of the client in the application of the Lean concept in the project. These explanations were presented by studying six individual case studies using different methodologies as shown in Table 4.


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Table 4. Used method in the six cases

Source: The presence of Lean Construction principles in Norways transport infrastructure projects, Norwegian University of Science and Technology, 2014.

The results that have been shown in this study can be summarized as follows: a) Using Lean concept in infrastructure projects, there will be more focus on the wastes and so ways determined of how to remove them from the projects. b) In the studied cases there was not a real integration between project parties, however, there was also no isolation in these cases for any member in the projects. c) The client is responsible to understand the concept of Lean and be supportive to it during the different projects phases. So, the first step is to conduct training sessions in Lean concept for the project parties. Kivistö, Ohlsson and Jacobsson, (2013) explains which lean principle is potentially applicable and determine the success factors needed to apply the Lean concept. This research is considered a qualitative study in which qualitative methods were used to respond to the research questions. By conducting a case study, the elements shown in Figure 6 were obtained.

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Fig. 5. The elements of the case study Source: Expanding Lean into Transportation Infrastructure Construction, Chalmers University of Technology, 2013.

Based on these elements, findings show that all Lean concept principles are suitable to be used in construction projects -especially road projects- and the success factors needed include applying the use of visual planning and applying Last Planner System. Fullalove, (2013) presented the benefits and enhancements that occur because of using Lean concept in road construction projects. Using Planned Percentage Complete (PPC), Reason of Non-Completion (RNC) and visual management (5S) led to saving costs (around £78,000) for a project with a total cost of £365Million. The followed actions took place: a) More meetings were arranged between engineers and section engineers. b) Engaging the sub-contractors to motivate them to finish their working activities on time. Gaio and Cachadinha, (2011), further assessed the benefits and advantages of applying Lean concept in road projects. The study demonstrated that through the application of Lean concept to road projects wastes will be minimized or removed. By applying Just In Time (JIT), the material in stock will be reduced, using 5S concept the material will occupy less space, productivity will increase and the number of injuries of workers will decrease. By taking into consideration the concept of Total Productive Maintenance (TPM), the failure of the machines will be reduced. Kahlen and Patel, (2011) presented a case study with the application of Lean concept; the results were summarized and analysed. The target of this study is to determine and list the factors that affect the rideability (rideability; the smoothness of the finished roads) of the highway construction projects and increase the supply chain efficiency to improve the rideability. Rideability is measured by using International Roughness Index (IRI); if International Roughness Index is high, this means the road is rough and rideability is low. The influencing factors and their results are:


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a) Asphalt Temperature; hotter asphalt temperature produce lower IRI. However, cooler bitumen temperature produce lower IRI. b) Work zone surface area; as the paving length increase per load, this produces lower IRI. c) Layer thickness; thinner length produces lower IRI. Jang and Kim, (2007) introduced a new measurement called Percentage of Constraint Removal (PCR) (its equation is shown below). The purpose of this study is to determine the correlation between this measurement and Last Planner measurements and to determine if this measurement can be represented in construction industry as workflow predictable. !" #$ " "#!%! &' ! ' ( )$ * ++ ,)# ( "#!%! #" & % - ./ 0 %#' #( &$ ( &

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Weekly Work Plan (WWP) will occur between week -1 and week 0. The purpose of this was determined by using three highway case studies. The study presented two phases; first phase of the projects used the traditional approach while in the second phase Lean Construction was used by applying Last Planner system (LPS). The findings show that there is no real relation between PCR and the improvement performance. The new measurement helped to determine if make-ready process was successfully done or not (main activities of make ready process are constraint analysis and constrain removal). Therefore, PCR could be reliable forecast for production process. Farrar, AbouRizk and Mao, (2004) used simulation modelling on road project to show the improvement by applying Lean concept. The researchers used case study and made comparison between the model (in which Lean concept was used) and the real project (in which traditional concept was used). This study explained the studied road project that had the following categories: a) Subgrade operations b) Aggregate operations c) Asphalt operations To apply Lean concept to the simulation model the following steps were used in the study. After the below steps were taken the results were obtained as shown in Table 5: a) Determine all the Non-Value Adding activities (NVA); candidates of improvement. b) Assume that the duration of these activities equals "zero" to determine their significant effect on the project. c) Run the simulation model.

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d) Sort the Non-Added Value Activities (NVA) in their ascending order to determine which of them have the greatest impact. e) Determine how to minimize the durations of Non-Added Value Activities (NVA). f) Assume that the durations of material supply equals "zero" to determine the impact on delivering the material to the site. g) Run the simulation model. h) Determine the process to minimize the duration of delivering the material to site. i) Determine the process to minimize the duration of Value Adding activities (VA). j) Add buffers to the total duration of the activities. This will minimize the impact of uncertainties. Table 5: Comparison between real cases study (Traditional approach used) and simulated (Lean concept used)

Source: Generic implementation of lean concepts in simulation models, Lean Construction Journal, 2004.

Table 6 summarize the previous studies that used Lean concept into road projects. From these studies by using Lean concept, improvements will occur in the cost and the duration for the road construction projects. However, some barriers prohibit applying Lean concept.

4. CONCLUSION Pettersen, (2017); Kahlen and Patel, (2011) explained that Toyota Production System (TPS) established the lean concept after WWII in the production industry. TPS attempted to face the challenges that emerged in Japan during this period, and they sought better relations with their customers. Lean


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concept has five principles; Value, Value Stream Mapping (VSM), Flow, Pull and Perfection, (Rodewohl, 2014). Some scholars in their work presented different barriers that could hinder the application of Lean Construction, (Gaio & Cachadinha, 2011; Heyl, 2015 Tezel, et al., 2016b; Farrar, AbouRizk and Mao, 2004). Among the mentioned barriers was the incorrect application of Lean Construction (Gaio and Cachadinha, 2011; Heyl, 2015; and Farrar, AbouRizk and Mao, 2004). In some cases, low interest from the different project parties as well as being intimidated to apply a new management tool to multi-million dollars projects acted as obstacles to the application of Lean Construction. Kivistö, Ohlsson and Jacobsson, (2013) listed the three types of project durations, which are Value Adding (VA) and Non-Value Adding (NVA) activities (NVA; categorized into essential and non-essential activities). Lean concept categorized all the wastes that can occur into eight types of wastes. These wastes can be relevant to Non-Value Adding activities and especially non-essential activities because they can be removed and will result in more benefit for the activity duration. Scholars listed some Lean tools that can be used in the construction industry, such as Last Planner System (LPS), 5S, Total Productive Maintenance (TPM) and Just In Time (JIT) concept (Gaio and Cachadinha, 2011; Pettersen, 2017; Tezel, et, al., 2016a; 2016b; Jang and Kim, 2007; Tezel and Aziz, 2016). By applying these tools in the construction industry, more improvements in time besides increasing the value of Planned Percentage Complete can result (Tezel, et al., 2016a; Tezel and Aziz, 2016; Heyl, 2015). Using Lean concept in a case study leaded to make a cost saving by Fullalove, (2013). Farrar, AbouRizk and Mao, (2004) demonstrated the improvement in the production rates and the durations by using simulation game, which applied Lean concept principles.

REFERENCES [1]

Daniel, E.I., Pasquire, C. and Dickens, G., 2016. Exploring the factors that influence the implementation of the Last Planner® System on joint venture infrastructure projects: a case study approach.

[2]

Farrar, J.M., AbouRizk, S.M. and Mao, X., 2004. Generic implementation of lean concepts in simulation models. Lean Construction Journal, 1(1), pp.1-23.

[3]

Fullalove, L.H., 2013. Examples of lean techniques and methodology applied to UK road schemes. In Proceedings of the 21th Annual Conference of the International Group for Lean Construction (IGLC).

[4]

Gaio, J. and Cachadinha, N., 2011. Suitability and benefits of implementing lean production on road works. IGLC-19, pp.579-589.

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[5]

Jang, J.W. and Kim, Y.W., 2007. Use of percent of constraint removal to measure the make-ready process. In Conference of the International Group for Lean Construction, Michigan, USA Christine Pasquire and Patricia Tzortzopoulos (eds) (Vol. 15, pp. 529-38).

[6]

Kahlen, F.J. and Patel, Y., 2011. Leaning the supply chain to maximize value delivery to the customer: A case study. Leadership and Management in Engineering, 11(2), pp.128-136.

[7]

Kivistö, G., Ohlsson, H. and Jacobsson, T., 2013. Expanding Lean into Transportation Infrastructure Construction.

[8]

Pettersen, M., 2017. Lean Construction in Norwegian Transport InfrastructureThe Client's Perspective (Master's thesis, NTNU).

[9]

Rodewohl, C.F., 2014. The presence of Lean Construction principles in Norways transport infrastructure projects(Master's thesis, Institutt for bygg, anlegg og transport).

[10]

Tezel, A., Koskela, L. and Aziz, Z., 2017. Lean construction in small-medium sized enterprises (SMEs): an exploration of the highways supply chain.

[11]

Tezel, A., Aziz, Z., Koskela, L. and Tzortzopoulos, P., 2016. Benefits of visual management in the transportation sector.

[12]

Tezel, B.A., Aziz, Z.U.H., Koskela, L.J. and Tzortzopoulos Fazenda, P., 2016. Visual management condition in highways construction projects in England.

[13]

Tezel, A. and Aziz, Z., 2016. Visual management/visual controls implementation pilot: 5S in Highways Construction and Maintenance.

[14]

Von Heyl, J., 2015. LEAN SIMULATION IN ROAD CONSTRUCTION: TEACHING OF BASIC LEAN PRINCIPALS. In Proceedings of 23rd Annual Conference of the Int’l. Group for Lean Construction. Perth. Australia (pp. 403412).

Ahmed ELKHERBAWY1 Jose-Antonio LOZANO2 Gonzalo RAMOS1 Jose TURMO1 1

Universitat Politècnica de Catalunya, BarcelonaTECH, 2 University of Castilla-La Mancha 1, 2 Faculty of Engineering

COMPARISON OF PROJECT MANAGEMENT AND LEAN CONSTRUCTION IN A REAL ROAD PROJECT Keywords: Lean Construction, Road project, Last Planner System, Percent Plan Complete, Root Cause of Delay, Total project duration

Abstract Project Management, PM, refers to the practice of planning, executing and controlling certain tasks to achieve specific goals at the specified time. Applications of this methodology (such as the Gantt chart) are commonly used in construction road projects. In order to increase productivity and reduce project costs, alternative management approaches (such as the Lean Construction, LC) can be followed. In this approach, the lean manufacturing principles are applied to achieve a delivering value with less waste (or in other words, with lower construction time). The aim of this study is to compare the traditional PM and the LC for the construction process of an actual road built in Cairo (Egypt) between the cities of Cairo and Alexandria. In this study, the analysis of certain parameters (such as the percent plan complete, root cause of delays or the total project duration) will be analysed for different construction scenarios. The results of the paper illustrate the advantages of using LC over the traditional PM approach in road projects.

1. INTRODUCTION Based on Project Management Body Of Knowledge, PMBOK (Rose, 2013), project time management includes the processes to plan and control the total project duration. On the one hand, these processes are as follows: 1) Plan schedule management. 2) Define activities. 3) Sequence activities. 4) Estimate activity resources. 5) Estimate activity durations. 6) Develop schedule. Finaly, controlling the main process is Control schedule. Toyota Production System (TPS) invented the lean concept and named it Lean Production LP and then it was adapted and applied as Lean Construction. This concept focuses on removing the wastes to meet the customers’ requirements (Sarhan, et al., 2017). This study presents a comparison between the PM Approach and LC with focusing on their impact on time schedule. This

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comparison will be applied through a simulation model on a real highway construction project, a connection between the centre of the city and the beginning of the main Cairo-Alexandria highway. The paper is organised as follows: In the first section, a review of previous studies on Project Management approach and Lean Construction is presented with the aim of the main principles and tools of each approach. In the second section, a case study where the different management approaches are compared and presented. In the third section, the results of this comparison are presented. In the fourth section, the results are shown. In the fifth and sixth sections the results are concluded and analysed using some correlations.

2. LITERATURE REVIEW In this section, a review of previous studies on PM Approach and LC. This state of the art provides useful insights for the comparison of the two approaches.

2.1 Project Management Approach Project Management Body of Knowledge (Rose, 2013) is focused on the Project Time Management. These areas are: 1) Project Integration Management. 2) Project Scope Management. 3) Project Time Management. 4) Project Cost Management. 5) Project Quality Management. 6) Project Human Resources Management. 7) Project Communications Management. 8) Project Risk Management. 9) Project Procurement Management. 10) Project Stakeholder Management. According to PMBOK (Rose, 2013), Project Time Management includes the “processes”, or principles to plan and control the total duration of the projects. These principles are as follows: 1) Plan Schedule Management; used to create the policies, procedures and documentation for planning, developing, managing and controlling the total project schedule. 2) Define Activities; determining and gathering all the activities that will be composed of sub-activities on the project. 3) Sequence Activities; defined as determining the predecessor (previous activity) and the successor (following activity) for each activity. 4) Estimate Activity Resources; estimating the resources for every activity that will be implemented in the required project. 5) Estimate Activity Durations; estimating the duration of each activity based on its requirements. 6) Develop Schedule; analysing, resources, durations and constraints of each activity to determine the total duration of the project. 7) Control Schedule; used to control the duration of the activities. It is used to update the project schedule based on the real situation. According to the PMBOK, (Rose, 2013), some of the most common PM’s tools are as follows: 1) Decomposition; means the breakdown of activities into subactivities. 2) Procedure Diagramming Method; is a technique where the activities “are represented by nodes”. With the following relationships: a) Finish

Comparıson of project management and lean constructıon ın a real road project

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to Start; the successor activity will start after the finishing of the predecessor one. b) Start to Start; the successor activity will start after the starting of the predecessor one. c) Finish to Finish; the successor activity will finish after the finishing of the predecessor one. d) Start to Finish; the successor activity will finish after the starting of the predecessor one. 3) Leads and Lags; a) Leads; the successor activity will begin before finishing the predecessor by two weeks. b) Lags; the successor activity will begin after the finishing the predecessor by two weeks. 4) Critical Path Method (CPM); used to estimate the minimum project duration. Any delay in the activities conducted under this path could affect the pace of progress of the whole project. For example, if there is a building project has a foundation activity on CPM; so by delaying this activity for one month, it will delay whole project by at least one month. 5) Critical Chain Method (CCM); allows the project engineers to add buffers on the project activities. This occurs due to the limited amount of resources or the risk that might come up during any stage of the project. For example, if there is a building project has a foundation activity on CPM; the project may be delayed due to the bad weather and lack of labour, so extra days may be added to cope with these delays. 6) Crashing the schedule; used to minimize the project duration by adding more resources or working overtimes. This technique is usually implemented on the activities on the CPM. 7) Fast tracking; similar to the previous process, however this is implemented by working on two activities in parallel. For example for this in road projects, is to start working on excavation for sub-base activity before completing the shop drawings. Aziz and Abdel-Hakam, (2016) focused on determining and collecting the reasons of delays concerning the previous studies, by using PM Approach. These studies were implemented on different types of construction projects from different countries. Based on Aziz and Abdel-Hakam, (2016), there are some reasons behind the delays, which were observed in a construction road project, which used Project Management Approach. This project had a plan duration of 18 months but was delayed for 12 additional months, due to a number of 293 reasons that were identified by the authors. The main reasons are as follows: 1) Failure of an electrical public cable in the construction site. 2) Working on the extension of international cables. 3) Delays that occurred due to the January 25th revolution1.

2.2 Lean Construction Lean Construction is a new technique (was formed in 1997 by Lean Construction Institute) focus on the elimination of the project wastes, leading to

!

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its continuous improvement. These wastes have their impacts on both the schedule and cost. Lean concept is focused on the five principles presented in Figure 1, according to many scholars (Mohammed and Khodier, 2017; Sarhan, et al., 2017; Rodewohl, 2014). These principles are as follows: 1) Value; understand the customers’ needs. 2) Value Stream; by making current state mapping, then the wastes (Non-Adding Value activities, not essential) will be identified and finally the future state mapping will be produced after making the modifications. 3) Flow; removing the wastes from the activities. 4) Pull Production; not delivering the material until the exact time when they are needed. 5) Perfection; continuous improvement of the last four steps.

Fig. 1. Lean concept Principles Source: EXAMINING THE ROLE OF LEAN MANAGEMENT IN LEADING ARCHITECTURE RENOVATION PROJECTS, Conference: ArchCairo7 Building Innovatively Interactive Cities, 2017.

According to Sarhan, et al., (2017) and Mihic, Sertic and Zavrski, (2014) the main Lean Construction tools are as follows: 1) Last Planner System. 2) Integrated Project Delivery System. 3) Total Productive Maintenance. 4) Just In Time. 5) Five Why’s. 6) 5S. 7) Value Stream Mapping.

2.2.1 Last Planner System (LPS) Last Planner System is a planning, monitoring and controlling system used to achieve Lean Construction targets by reducing wastes, increasing productivity and improving the workflow reliability, (Porwall, 2010; Jang and Kim, 2007; Sarhan, et al., 2017; Issa, 2013). According to Last Planner System is composed of four steps which should be applied to be successfully implemented, (Hamzeh, Zankoul and El Sakka, 2016;


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Hamzeh, 2009; Jang and Kim, 2007; Porwall, 2010) as follows: 1) Master scheduling; creating the milestones. 2) Phase scheduling; determining the activities that should be done. 3) Look-ahead planning; breaking down the activities, determining and identifying the wastes and assigning the responsibilities to finish the activities. Look-ahead planning has three steps as follows: 1) 6 to 3 weeks before the activity’s execution week; the tasks were taken from the phase scheduling and inserted into the look-ahead planning. The general wastes (such as the information of design and types of materials) will be removed. During this step, the tasks are broken down. 2) 2 weeks before the activity’s execution week; tasks are continuously broken down and more specific wastes, related to specific wastes of task (the necessary requirements for the tasks such as more details about materials and resources), are identified and removed. 3) 1 week before the activity’s execution week; in this stage the process of pulling and screening are implemented. Pulling is referring to determine the tasks that SHOULD be made ready depending on the actual site demand. Screening is referring to determine the actions required to remove different type of constraints. 4) Weekly work plan/Commitment plan (the activity’s execution week); refers to the execution week in which the Percentage Plan Complete should be calculated. Porwal, (2010) stated that LPS is a collaborative technique because Last Planner System is a collaborative technique; because it gathers the last planners in a bigger team work to finalize the work. Figure 2 shows the Last Planner System’s main components. First, the project objective is determined and identified, then by providing more information the milestones of the project are inserted. Last Planners will determine which tasks SHOULD be done (Pulling process ) during the six weeks look-ahead planning while trying to expect and eliminate the wastes that could occur. Before the execution week the Last Planners will identify which activities that CAN be done; these activities are not free from wastes/constraints but they can be done based on the pull scheduling principle. Some of these activities are free from wastes/constraints and in this case are regarded as activities, which WILL be done. During the execution week, Percentage Plan Complete of the activities that are done, referred to as DID, will be determined and calculated; Percentage Plan Complete is the actual number of finished tasks divided by the expected number of finished tasks. Regarding the activities that are not finished, the concept of five Why’s is applied to determine the cause and the effect of the problem. It is used to Define, Measure, Analyse, Improve and Control (DMAIC) the activities. For example in building projects, painting wall activity was not finished on time. The process DMAIC will be implemented: Define: due to the painting material travelled late; Measure: determine the time duration of this delay; Analyse: expect the affection on the whole duration of the project; Improve: solve the

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reasons with the material supplier (the main cause of the delay); Control: try to prevent this reason being repeated again.

Fig. 2. Last Planner System Source: LAST PLANNER SYSTEM – AREAS OF APPLICATION AND IMPLEMENTATION CHALLENGES, Institute of Engineering and Science, 2010.

Porwal, (2010) listed the benefits and barriers for Last Planner System. First, the benefits are as follows: 1) Increase in Reliability. 2) Improvement in time to deliver the project. 3) Increase in labour Productivity. 4) Increase in Safety. 5) Increase in Quality. 6) Continuous improvement in time, quality and cost. While some of the barriers that face Last Planner System are as follows: 1) Human nature do not like to change. 2) Negative attitude toward the new technique. 3) Lack of experience and training. 4) Lack of leadership. 5) Lack of support from stakeholders. 6) Applying Last Planner System in late project’s state. 7) Lack of collaboration.

2.2.2 Integrated Project Delivery (IPD) The American Institute of Architects (AIA) defined Integrated Project Delivery as: “a project delivery approach that integrates people, systems, business structures and practices into a process that collaboratively harnesses the talents and insights of all participants to optimize project results, increase value to the owner, reduce waste, and maximize efficiency through all phases of design, fabrication, and construction.”2 (Mihic, Sertic and Zavrski, 2014).

Mihic, M., Sertic, J. and Zavrski, I., 2014. Integrated project delivery as integration between solution development and solution implementation. Procedia-Social and Behavioral Sciences, 119, pp.557-565.


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The American Institute of Architects (AIA) made a comparison between traditional and integrated design processes based on the collaborations of the stakeholders. Figures 3 and 4 shows that almost all the main stakeholders are involved in the early stage of the project which increases the probability of identifying and removing the wastes. In contrast, this does not occur in the traditional design process, (Mihic, Sertic and Zavrski, 2014).

Fig. 3. Traditional design processes Source: Integrated project delivery as integration between solution development and solution implementation, 27th IPMA World Congress, 2014.

Fig. 4. Integrated design processes Source: Integrated project delivery as integration between solution development and solution implementation, 27th IPMA World Congress, 2014.

El Asmar, Hanna and Loh, (2013) presented the concepts of Design Build (DB) and Design Bid Build (DBB). On the one hand, Design Build (DB) refers to having one contractor for both construction and design, while on Design Bid Build (DBB) refers to having two separate contracts for construction and design. Figure 5 summarizes the difference between Design Build (DB), Design Bid Build (DBB) and Integrated Project Delivery (IPD), with a focus on the collaborations factor. For example, Design Bid Build, the contract is signed with the contractor after the work of the design is fully finished (100% finished). In case of Design Build, the contract is signed with the contractor after the 20% of the work of the design is finished. Under the Integrated Project

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Delivery approach, all the stakeholders collaborate before the start of the design stage.

Fig. 5. Collaborations in DB, DBB, and IPD Source: Quantifying Performance for the Integrated Project Delivery System as Compared to Established Delivery Systems, Journal of Construction Engineering and Management, 2013.

El Asmar, Hanna and Loh, (2013) concluded that using Integrated Project Delivery results in higher quality and faster projects without significant extra cost. Azhar et al., (2015) had a general conclusion that using IPD improves project delivery effectiveness. The study also lists some benefits of using Integrated Project Delivery are as follows: 1) Early involvement of all stakeholders and close collaboration. 2) Sharing risks and profit. 3) Trust and mutual respect. Mihic, Sertic, and Zavrski, (2014) identified the main barrier that faces the use of IPD in the Croatian construction sector; there are no laws that explain if using IPD is legal or not. However, Public Procurement Act (2005) does not forbid the use of IPD by private investors in contrast to the public investors.

2.2.3 Total Productive Maintenance (TPM) Singh et al., (2012) explained the reason of using Total Productive Maintenance because it focuses on the maintenance and reparation of the equipment to prevent their failure. The author stated that Total Productive Maintenance is a maintenance approach that focuses on improving the effectiveness of the machines and preventing their breakdowns. Total Productive Maintenance has one foundation, which is 5S, and eight pillars, Figure 6 (5S is a Lean tool refers to Sorting, Setting in order, Shinning, Standardizing and Sustaining, which is a housekeeping method).


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Fig. 6. TPM Pillars Source: Total productive maintenance (TPM) implementation in a machine shop: A case study, Chemical, Civil and Mechanical Engineering Tracks of 3rd Nirma University International Conference on Engineering, 2012.

Based on the previous studies no barriers have been found, while the benefits that can occur after applying Total Productive Maintenance are as follows, (Eti, Ogaji and Probert, 2004): 1) Increasing the machines effectiveness. 2) Higher levels of quality and safety. 3) Decreasing cost. 4) The labours are motivated to do their tasks. Singh, et al., (2012) state other benefits after applying Total Productive Maintenance are as follows: 1) Decreasing the activity time. 2) Decreasing machines’ breakdown. 3) Increasing performance efficiency for the machines. 4) Increasing the overall equipment effectiveness. 5) Increasing the machine’s availability.

2.2.4

Just In Time (JIT)

Just In Time technique is a Pull System technique which refers to delivering the accurate necessary amount of material in the exact time of its need. This tool seeks to minimise or remove the inventories, which leads to minimizing the handling process and increasing labour productivity, (Mohammed and Khodier, 2017). Like the Total Productive Maintenance tool, there is no determination of barriers for JIT in the previous studies. It is essential to mention that the absence of Just In Time concept could lead to the following consequences (Hosseini, Nikakhtar and Ghoddousi, 2014): 1) Delay in delivering the materials. 2) Decreased labour productivity. 3) Unavailability of the material, which leads to increasing the project durations. 4) The movement of labours increase which

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tend to make them demotivated. 5) Having unnecessary inventories, which can increase the cost of the project.

2.3 Lean Construction and Project Management Approach Comparison According to Mohammed and Khodier, (2017) the main differences between Lean Construction and Project Management Approach are as follows: 1) Project Management Approach focuses on the improvement of each activity of the project; while Lean Construction focuses on the improvement of the value of the whole project. 2) Project Management Approach does not focus on reducing the variations; while Lean Construction focuses on reducing the variations at the early stages of the project. 3) Project Management Approach leads to taking action after the problem occurs; while Lean Construction highlights the importance of preventing the occurrence of the wrong actions. 4) Project Management Approach is a push driven method; while Lean Construction is a pull driven method.

3. RESEARCH METHOD 3.1 Project definition The project analysed in this study is a real highway project. It is located in a new city in Cairo called 6th of October. It is regarded as a connection between the centre of the city and the beginning of the main Cairo-Alexandria highway. The length of the project is 12.812km in each of the two directions. The total width of the project is 17m. The main contractor is one of the biggest public companies in Egypt called Arab Contractors. The working hours of the project during weekdays are scheduled from 08:00 in the morning to 17:00 in the evening including one hour for lunch. It is worth mentioning that the construction sector in Egypt takes one day off as weekend and this project runs during weekdays.

3.2 Data collection This type of projects – infrastructure projects– depends mainly on the equipment and not on the skill of the labours as the case is in building projects. For this reason, there are many types of machines; each of them has a different use. These machines are shown and defined in Figure 7 and Table 1.


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Fig. 7. Road project machines Source: own research

To collect information about the duration of the sub-activities, site observation was done for 30 days, four hours every day (except Friday which is a weekend). Each sub-activity under each activity was observed and its duration measured. Further, in order to have full data about each sub-activity, information was collected from site engineers orally and through documents such as the shop-drawings and the time schedule of the project. In order to calculate the duration of each sub-activity, the Value Adding (VA) activities durations were observed, taking into account that each machine has a minimum, a maximum and an average speed. The speed of each machine was determined based on the observation while calculating the duration it took to finish the sub-activity work in a 200 meter section with the different speeds. In case of the Non-Value Adding (NVA) activities, three durations (minimum, maximum and average) were also observed during the manoeuvring of the machine. From the VA and NVA activities duration, the total durations were calculated for each sub-activity. The wasted time was not include in the time durations calculated. During the site visits, eight wastes that occurred in one month were observed. More details about these wastes are shown and explained in Table 2. This table further demonstrates the Lean tools that are used in the simulation to eliminate the identified wastes. Similar to the observation of the durations of each sub-activities, each time waste was observed during each sub-activity. Two of these eight wastes (W4 and W8) are calculated per meter not per occurrence as other wastes; the reason for this is because these two wastes depend on the material quantity. In case of W1, this mainly refers to the time unnecessarily wasted during the inspection of an activity. For example, in several instances, an

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activity finishes and the work process was frozen while waiting for the consultant to inspect the finished activity. During the observation this happened and the consultant did not show up that day which led to the following activity being postponed till the next day after inspection. Figure 8 shows an example of delayed work; the equipment stopped waiting for the inspection. One way to overcome this obstacle/cause of waste is by allowing the equipment to work in another section until the finished area is inspected.

Fig. 8. Waiting for inspecting the finished activity Source: own research

In the second waste W2, problems that occurred and could be resolved using the JIT concept are demonstrated in Figure 9, where the paving finisher is shown waiting for the asphalt trucks which arrived late. The perfect occurrence is to deliver the material exactly on time, neither late nor early. For W3, which displays shortage of machine gas due to lack of maintenance; however by applying maintenance and repair this problem can be eliminated. For W4, this waste mainly refers to the long distance between the loading and unloading areas.

Fig. 9. Paving finisher waiting the asphalt trucks Source: own research


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W5, which is the equipment stopped for mechanical problems, is similar to W3 because they occurred due to lack of maintenance and repair, as shown in Figure 10. If there was continuous maintenance of machines, this would not have been the case. In addition, regarding W6, as shown in Figure 11, double drum rollers, which is the equipment, used to mash the surface of asphalt layers uses water on the drum during rolling. This equipment ran out of water in the middle of work activity and the water sprinkle was used to refill it. The mechanical section should check on the water in the double drum rollers to prevent this waste of time and cost.

Fig. 10. Waiting for mechanical problems

Fig. 11. Double drum rollers filling with water Source: own research

Regarding W7, sometimes the paving finisher had to make two trips to pave the road with asphalt because of the lack of compatibility between the width of the road and that of the paving finisher; that is, the road’s width is too big for the paving finisher to pave in one trip. This type of waste causes can be addressed by increasing the width of the pavement, during the paving process

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the width of the paving finisher ranges from 3meters to 6meters. Regarding W8, in addition to the mentioned causes of waste, sometimes the asphalt truck’s driver suddenly drops a significant amount of asphalt leading to a time gap between the moment when the asphalt was dropped and the time needed by the paving finisher to pave it. Table 1. Resource for each sub-activity Activity

Sub-activity

Resource

Sub-base layer works

Unloading Levelling Sprinkle Compact Unloading Levelling Sprinkle Compact Unloading Levelling Sprinkle Compact MC Sprinkle (referring to Medium Curing) Putting first asphalt layer

Aggregate truck Grader Water sprinkle Single drum roller Aggregate truck Grader Water sprinkle Single drum roller Aggregate truck Grader Water sprinkle Single drum roller MC sprinkle

1st aggregate layer works

2nd aggregate layer works 1st Asphalt layer works

nd

2 Asphalt layer works

Compact RC Sprinkle (referring to Rapid Curing) Putting second asphalt layer Compact

Asphalt truck + Paving finisher Double drum roller RC sprinkle

Asphalt truck + Paving finisher Double drum roller


Table 2. Wastes explanation and modification Wastes

Explanation

W1

The work of the activity was finished but could not start the following activity (dependencies) because the consultant should inspect the finished one first. The asphalt trucks were delivering

W2

Waste modified (using Lean tools) Increase the coordination and communication between project parties. Apply Integrated Project Delivery System (IPD). Deliver the material on


Wastes

W3

Explanation early which led to wait on site or the paving finisher was waiting for the asphalt trucks arriving late. The machine had shortage of gas, which led to a waste of time.

W4 (Per meter)

Transport the aggregate to the working area. For distance more than 5Km far.

W5

The equipment stopped for mechanical problems.

W6

Double drum rollers ran out of water.

W7

Paving finisher had to make two trips to pave the road with asphalt because of the width of the road.

W8 (Per meter)

The asphalt truck was waiting until the paving finisher pave the asphalt dropped down on it.

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Waste modified (using Lean tools) time. Apply Just In Time (JIT). Make maintenance and repair. Apply Total Productive Maintenance (TPM). Increase the coordination and communication between project parties. Apply Integrated Project Delivery System (IPD). Make maintenance and repair. Apply Total Productive Maintenance (TPM). Make maintenance and repair. Apply Total Productive Maintenance (TPM). Increase the coordination and communication between project parties. Apply Integrated Project Delivery System (IPD). Increase the coordination and communication between project parties. Apply Integrated Project Delivery System (IPD).


3.3 Objective of the simulations: In the beginning, the simulation is carried out using the software Simio3. The target of this simulation is to apply Project Management approach and Lean Construction on the studied project to produce results that are accurate enough to resemble reality. "

#

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Pilot model: Simple structure (Figure 12) - Simulation PM-OW (Project Management with Observed Wastes), Table 4: Different values for time activities and observed wastes duration will be used as input: using a random function based on observed information (different triangular laws 20%, 10%, 5% and 0%). - Simulation PM-EW (Project Management with Expected Wastes), Table 5: Different values for time activities and expected wastes duration will be used as input: using a random function based on observed information (different triangular laws 20%, 10%, 5% and 0%). The observed durations are the 0%. - Simulation LC (Lean Construction): Different values for time activities will be used as input: using a random function based on observed information (different triangular laws 20%, 10% and 5%). Based on literature (Porwall, 2010; Jang & Kim, 2007; Sarhan, et al., 2017; Issa, 2013; Mihic, et al., 2014; El Asmar et al., 2013; Azhar et al., 2015; Singh et al., 2012; Eti, et al., 2004; Mohammed & Khodier, 2017; Hosseini, et al., 2014), wastes are eliminated from this simulation.

Fig. 12. Pilot simulation Source: own research

The three equations below are used as inputs inserted into the software to get from them the outputs for Productivity of each activity (as occurred in the project), Root Cause of Delay (RCD) and Percent Plan Complete (PPC).

183


$% +0

&

'&! , !-

&

) *

1 2 + 5 3 4 67889 3 4

RCD% = PPC% =

'( *

) #+

.&

'

!"

!"#

! )

*

#

#

/

:; =?@> ABCD EFG?HI ;H ;J=?K?=L+MNN

OP=;Q =?@> PR ; ;J=?K?=L :SOTAUO :VWOX OSYX

AJJFGG>E ZGPEFJ=?K?=L PH [>>\ ]GPEFJ=?K?=L Z>G [>>\

RPG >;J^ ;J=?K?=L +MNN

]Q;HH>E ZGPEFJ=?K?=L PH [>>\ _>GP X`Z>J=>E ZGPEFJ=?K?=L Z>G [>>\

RPG >;J^ ;J=?K?=L

3.4 Model explanation (Simulations LC and PM): The three simulations (two using PM approach and one using LC) will each apply following steps; there are eight activities (Categorized as entities in Simio): Sub-Base Layer (filling with material from the site and from outside the site), First Aggregate Layer, Second Aggregate Layer, MC sprinkle (referring to Medium Curing), First Asphalt Layer, RC Sprinkle (referring to Rapid Curing) and Second Asphalt Layer. The study focuses on one section of the project (as a pilot). This section will have its sub-activities (Categorized as tasks in Simio), for example, having four sub-activities, Unloading, Levelling, Sprinkle and Compact. Every sub-activity will require a number of resources (for example, Aggregate Trucks will be used in Unloading). The total time will be identified and added for each sub-activity. Additionally, every sub-activity will have its waste (wastes are W1, W2, W3, … W8) and these wastes will be categorized under a group named as Root Cause of Delays (RCDs). First, eight entities are created representing the eight activities, and then the pilot section will be added to the model. The section will contain 18 subactivities; every sub-activity will use mainly one type of machinery. Finally at the end of each week, two expressions will be calculated (PPC and RCD) based on their equations, while at the end of the simulation the final duration of each activity will be estimated. Table 3 presents a list of assumptions for the three simulations. Tables 4 and 5 present the types of wastes that were observed/expected while working on every sub-activity. While Table 6, shows the number of times each waste

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occurred and the percentages of its occurrence. In simulation PM-OW, the percentages are the observed number of occurrence over the maximum number of occurrence. While in simulation PM-EW, the percentage of occurrence of each waste is assumed to be 100%. The last simulation (LC), these percentages went down to zero for all wastes; after applying the modifications presented in Table 2, these wastes were eliminated. Table 3. List of assumptions # 1. 2.

Assumptions The road will be divided into sections (each section has the same length). Each section is composed by different layers each one is carried out into different activity and one is built after the previous one is completed. Every activity is introduced into the simulation as entity. Working in sub-activities are sequenced (e.g: in activity sub-base, if sub3. activity unloading in section 12 finishes, aggregate truck will start working in section 13 on sub-activity unloading, and so on) Sub-activities of each activity are modelled as tasks. 4. Every activity will have its value of PPC and RCD 5. Every group of machinery has the same characteristics (e.g.: working 6. time, equipment number, waste times). Every machinery will work in each one sub-activity (except putting 7. asphalt layers). Total time, QSiRate and wastes are defined randomly. 8. Triangular random expressions. 9. The values of the total time and wastes time are obtained from 10. observation. The wastes are simulated as delayed times among activities. 11. No overlapping between any two sub-activities. 12. Source: own research

Table 4. Wastes occurrence during every sub-activity (Observed)

Activity

Sub-activity

Sub-base layer works (Each layer)

Aggregate truck Grader Water sprinkle Single drum roller Aggregate truck Grader Water sprinkle

1st aggregate layer works (Each layer)

Pebbles wastes (As occurred in the site visiting) W4 W1, W5 W1 W1 W4 W1, W5 W1


Activity

Sub-activity

nd

2 aggregate layer works

MC 1 Asphalt layer works st

RC 2 Asphalt layer works nd

Single drum roller Aggregate truck Grader Water sprinkle Single drum roller MC sprinkle Asphalt truck Paving finisher Double drum roller RC sprinkle Asphalt truck Paving finisher Double drum roller

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Pebbles wastes (As occurred in the site visiting) W1 W4 W1, W5 W1 W1 W1 W2, W3, W7, W8 W2, W3, W6 W1 W2, W3, W7, W8 W2, W3, W6


Table 5. Maximum wastes occurrence during every sub-activity (Expected) Activity

Sub-activity

Sub-base layer works (Each layer)

Aggregate truck Grader Water sprinkle Single drum roller Aggregate truck Grader Water sprinkle Single drum roller Aggregate truck Grader Water

1st aggregate layer works (Each layer)

2nd aggregate layer works

Pebbles wastes (As occurred in the site visiting) W4 W1, W3, W5 W1, W3, W5 W1, W3, W5 W4 W1, W3, W5 W1, W3, W5 W1, W3, W5 W4 W1, W3, W5 W1, W3, W5

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Activity

Sub-activity sprinkle Single drum roller MC sprinkle Asphalt truck Paving finisher Double drum roller RC sprinkle Asphalt truck Paving finisher Double drum roller

MC 1 Asphalt layer works st

RC 2 Asphalt layer works nd

Pebbles wastes (As occurred in the site visiting) W1, W3, W5 W1, W3, W5 W1, W2, W3, W5, W7, W8

W1, W2, W3, W5, W6 W1, W3, W5 W1, W2, W3, W5, W7, W8

W1, W2, W3, W5, W6


Table 6. Wastes Information for simulations PM & LC

Waste

# of occur. (Observe d)

W1 W2 W3 W4 W5

35 4 4 11 11

% of % of occu occur. r. % of (Priority) occur. (Prio Max. # of Simulati (Priority) rity) on LC occur. Simulati Simu (Expecte latio on PM d) OW n PM EW 0% 100 39 89.74% % 0% 100 4 100.00% % 0% 100 39 10.26% % 0% 100 11 100.00% % 0% 100 39 28.21% %


Waste

# of occur. (Observe d)

W6

2

W7

2

W8 W9

2 35

W10

4

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% of % of occur. occu (Priority) % of r. occur. (Prio Max. # of Simulati on LC (Priority) rity) occur. Simulati Simu (Expecte on PM latio d) OW n PM EW 0% 100 2 100.00% % 0% 100 2 100.00% % 0% 100 2 100.00% % 0% 100 39 89.74% % 0% 100 4 100.00% %


3.4.1 -

-

Flow charts: Simulation PM: 1- Input data (Waste deviation: +-5%, +-10%, +-20%) a. i=1 b. N=number of waste deviations analysed =3 c. Do (Waste deviation =i) if i + (b) and -(a) < -(b) + (a) > + (b) and -(a) = -(b) 1. condition: a is superior to b.

+ (a) = + (b) and -(a) < -(b) + (a) = + (b) and -(a) = -(b) 2. condition: a is indifferent to b.

+ (a) > + (b) and -(a) > -(b) + (a) < + (b) and -(a) < -(b) 3. condition: a and b cannot be compared.

(a) = + (a) – -(a)

(6)

According to this formula, if (a) > (b) for two decision points such as a and b, then decision point a is superior to decision point b. If (a) = ( b), decision point a is indifferent to decision point b.

3.1.2. PROMETHEE Method process algorithm Flow diagram relevant to the method is provided in Figure 1.

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Latif Onur U ur

Fig. 1. PROMETHEE Method process algorithm

3.1.3. GAIA Plaine Following the indication of alternatives on a k dimensional (at a dimension as much as the number of criterion) space, in order to be able to present the criteria and alternatives to the decision maker through a more understandable projection by using the Principal Components Analysis (PCA), a plane is formed by calculating the projections on a 2 dimensional plane from a k dimensional space. This place on which the alternatives and criteria are being indicated is called the GAIA plane. Actually this plane is corresponding to Epur which is known from design geometry. The geometric presentation of alternatives and criteria on the GAIA plane will provide a significant richness while assessing the problem. This technique is used in the decision making process especially for determining

Selectıon of archıtecture company wıth promethee method

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the significance of each criterion. Moreover, by this technique, the purposes such as apprehending the preference rates on the criteria, determining the homogenous alternative groups, selecting the good alternatives from among the ones under specific criteria, determining incomparability status among the alternatives may be realized [18] [11]. As the GAIA plane presents a visual support to the decision maker as being constructed on the results of PROMETHEE method, it is bringing in an advantage to PROMETHEE method compared to other multi criteria decision making methods [1] [7]. Some significant issues regarding the indication of the data of PROMETHEE approach with the assistance of GAIA plane may be referred as follows [1]; the discriminator feature of this criterion and its significance in affecting the decision rod is as much as the length of the rod (axis) indicating the criteria. The criterion rods indicating the same direction belong to criteria showing similar features. And the criterion rods indicating different directions belong to criteria which are in conflict with each other. The alternatives having similar values are close to each other on GAIA plane. If the alternatives have a high value on a criterion, then that alternative is close to that criterion rod on the GAIA plane [20] [13]. If the discrimination power of the criteria is low, then the criterion rod will be short. Because as the criteria with low discrimination power will be more vertical to GAIA plane, their projections will be close to each other, and they will look shorter on the graphical representation [21] [14]. Against the determination of the positions of alternatives and criteria, weights are used in showing the decision rod on GAIA plane. As the weights determined by the decision maker will indicate the preferences of the decision maker, the decision rod will indicate the preference direction of the decision maker. If the decision rod is long, it indicates that there is a strong decision power. Long decision rod directs the decision maker to select the alternatives in the direction indicated by the decision rod. In this case, as the criteria in the direction indicated by the decision rod don’t conflict much, it becomes easy for the decision maker to direct to most suitable alternative(s). If the decision rod is short, there is no strong decision power. It means that the criteria conflict strongly as per these given weights, and that it becomes hard to select the most suitable alternative(s) [17] [10].

4.Application Job descriptions for this application were reviewed, interviewed by experts, and the qualifications of a technical architect firm were assessed. By using all these data, criteria to be evaluated by candidate companies have been determined. The criteria specified are listed below. Visual PROMETHEE program is used in the application.

Criteria:

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Latif Onur U ur

•

K1: Firm ages

•

K2: Technical persons which works in per firm

•

K3: Turn overs of firms (miilion TL/year)

•

K4: Complated projects of firms

•

K5: Technical softweres of firms

Candidate architecture firms are named A, B, C, D and E. A decision matrix was established with the evaluations made for each company (See Table 2.) Table 2. Decision matrix Criteria Firm ages Technical persons Turn overs (million TL/year) Completed projects Technical softweres

A 12 8

Architecture Firms B C D 18 11 8 9 11 7

1,2 12 14

1,4 14 11

0,9 8 9

E 22 10

0,8 6 8

0,75 8 10

4.1. Determining Criterion Weights and Ordering Alternatives At this stage of the implementation all the criteria first determined are deemed to have equal significance levels and “one” value is assigned to each criterion as the weight value. All criteria were then weighted according to expert opinion. The weights given in the second (weighted) condition are shown in Table 3. Table 3. Criteria wheigts

Criteria weights

K1

K2

K3

K4

K5

%10

%30

%30

%15

%15

After this step, two different calculations (weightless and weighted) were made taking into account the decision matrix and weights.


249

4.2. Solution with Visual PROMETHEE Program 4.2.1. Criterion Weights Equals Data entry to program is shown in Figure 2. Criteria attributes, weights, preference functions and function parameters are entered into the interface.

Fig. 2. Visual PROMETHEE data input

Positive, negative and net superiority values are calculated by evaluating alternatives. The calculated superiority values are shown in Table 6 below.

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Latif Onur U ur

Table 4. Superior Values of Criteria (Weightless)

Subsequently, partial priorities were determined with the PROMETHEE I method and full priorities were determined with the PROMETHEE II method (see Figures 3 a and b)

(a)

(b)

Fig. 3. a) PROMETHEE I ve b) PROMETHEE II (Weightless)


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For PROMETHEE I method, Firm B is the best solution of the problem. The Second is Firm A for this method. According to PROMETHEE II method, B is the best alternative company according to the exact priority order. Candidates are listed as B, E, A, C, D at worst.

Fig. 4. GAIA Plane (Weightless) When the GAIA Plane is considered, the criterion with the most disintegrating feature is the paradise they rotate in one year (turn over). The situation of the alternatives according to the criteria is also shown in this graphic (Fig.4.). The preference vector also represents A alternative. These results does not overlap with PROMETHEE I and PROMETHEE II methods’ results.

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4.2.2. Condition Weighted by Criteria Using the criterial weights given in Table 4, the data is entered into the interface as shown in Fig. 5.

Fig. 5. Data Entry with Different Criteria Weights Positive, negative and net superiority values are calculated by evaluating alternatives. Calculated superiority values are shown in Table 5. below.


Table 5. Superior Values of Criteria (Weighted)

(a)

(b)

Fig. 6. a) PROMETHEE I ve b) PROMETHEE II (Weighted)

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Latif Onur U ur

When weights given to the criteria, it is the best alternative B company according to the exact priority order found by PROMETHEE I method. The same applies to the PROMETHEE II method.(see Fig.6 a and b)

Fig. 7. GAIA Plane (Weighted) When the GAIA plane is examined (see Figure 7), it shows an alternative to the preference vector A. In this case the results do not overlap with PROMETHEE I and PROMETHEE II.


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5.Results Decisions made in the construction sector are becoming more and more complex and there are a number of criteria that affect a decision. Given the wrong decisions can cause high costs. At this stage, new computer-aided approaches have been developed to help decision-makers. One of these approaches is the PROMETHEE approach. This approach is based on a weighting of the criteria that affect this decision when it makes a decision among various options. The most important advantage of the approach is that it is possible to change the weight points initially given within the decision making process. Some decisions may require that benchmark values in high numbers be combined with benchmark values in low numbers. PROMETHEE is one of the multi-criteria decision-making methods that allow examination of values in opposite structures together. However, as in most of the multi-criteria decisionmaking methods, the measurement units of the evaluation criteria differ in the PROMETHEE approach. The PROMETHEE ranking technique is one of the most effective and easiest methods in the solution of multi-criteria problems. By setting more than one criterion in the process of decision making, these criteria are assigned weights according to their importance, and the ranking among the alternatives can easily be realized thanks to the computer software as in this study. The most important reason for preferring the PROMETHEE method in studying is; to define individual scores for each criterion and to evaluate the criterion in itself, in this way both healthier and more reliable interpretations can be made. In practice, comparisons are made according to the binary comparison method and all the latest alternatives are evaluated at the same time. Architectural office selection with PROMETHEE has two important advantages in addition to other ranking methods. One of these advantages is that a different preference function can be used for each factor used in the evaluation of alternative architectural firms; and the second is to obtain partial and complete sequences of alternatives. In this way, it is ensured that decision makers are able to rescue each criterion in a similar way. Thanks to these advantages, the effectiveness and correctness of the architectural office selection process has been increased. Since the PROMETHEE approach is easy to understand and simple to use, it can be easily applied to similar problems, and other criteria can be used to select organizations that offer different types of services in the construction industry, such as when choosing an architectural office. In other studies, it is possible to make comparative analyzes with different methods using PROMETHEE method.

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Table 6. Best companies for every method Weightless PROMETHEE I PROMETHEE II GAIA Plane B B A

Weighted PROMETHEE I PROMETHEE II GAIA Plane B B A

The companies that received the first order as a result of the calculations made are given in Table 6. In case the criteria are weightless (equal weight), company B is the best firm according to PROMETHEE I and II methods. GAIA Plane analysis with no weight; A company as the best company. In the case where the criteria are weighted (different weight), the best firm according to PROMETHEE I and II methods is again B firm. GAIA Plane analysis with no weight; also shows A as the best company. It would be appropriate to focus on B and A firms for decision makers fort he best solution. It has been seen that the results obtained are consistent and appropriate.

REFERENCES [1]

Amponsah, S.K. , Darwah, K.F. ve Inusah, A. (2012), “Logistic Preference Function for Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE) Decision Analysis”, African Journal of Mathmetics and Computer Science Research, 5(6), 112-119.

[2]

https://www.csb.gov.tr/db/strateji/editordosya/Mehmet_Ali_SimsekUzmanlik_Tezi.pdf

[3]

H. enkayas1, H. Hekimo lu, (2013), “Çok kriterli Tedarikçi Seçimi Problemine Promethee Yöntemi Uygulaması”, Verimlilik Dergisi, 66-67.

[4]

A. Özda o lu, Üretim letmelerinde Lazer Kesme Makinelerinin Promethee Yöntemi le Kar ıla tırılması, Uluslararası Yönetim ktisat ve letme Dergisi, Cilt 9, Sayı 19, 2013.

[5]

Genç,T.. PROMETHEE Yöntemi ve GAIA Düzlemi, Journal of Economics & Administrative Sciences / Afyon Kocatepe Üniversitesi ktisadi ve dari Bilimler Fakültesi Dergisi, 2013.

[6]

Da deviren M., Eraslan E., PROMETHEE Sıralama Yöntemi le Tedarikçi Seçimi, Gazi Üniv. Müh. Mim. Fak. Der., Cilt 23, No 1, 69-75, 2008

[7]

Genç T., ‘’PROMETHEE Yöntemi ve GAIA Düzlemi’’ Journal of Economics&Administrative Sciences /Afyon Kocatepe Üniversitesi ktisadi ve dari Bilimler Fakültesi Dergis15.1, 2013

[8]

Genç T., Masca M., TOPSIS ve PROMETHEE Yöntemleri le Elde Edilen Üstünlük Sıralamalarının Bir Uygulama Üzerinden Kar ıla tırılması, Afyon Kocatepe Üniversitesi, BF Dergisi (C. XV, S. II, 2013) , s.539-546.


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[9]

Prvulovic S., Tolmac D., Radovanovic L., “Application of PROMETHEE-GAIA Methodology in the Choice of Systems for Drying Paltry-Seeds and Powder Materials”, Journal of Mechanical Engineering, 2011, s.778-784.

[10]

Pavi I., Babi Z., “The Use Of The Promethee Method in The Location Choice Of A Production System”, International Journal of Production Economics, 1991, s.165-174.

[11]

Mareschal B., Brans J. P., (1988) “Geometrical Representations for MCDA”, European Journal of Operational Research, 34, ss.69-77

[12]

Yıldırım B. F. , Önder E., Çok Kriterli Karar Verme Yöntemleri, s.175-186, Dora Yayınları, 2015

[13]

Brans, Jean-Pierre ve Mareschal, Bertrand, (2005) “PROMETHEE Methods”, Figueira vd. (ed.) Multiple Criteria Decision Analysis, State of the Art Survey, New York, Springer Science.

[14]

De Smet, Yves, Lidouh, Karim, “An introduction to Multicriteria Decision Aid: The PROMETHEE and GAIA Methods”, http://code.ulb.ac.be/~yvdesmet/ (05 Mayıs 2012)

Latif Onur U UR1 Rıfat AKBIYIKLI1 Ali ATE 1

1

University of Düzce, Faculty of Technology, Civil Engineering Dept., Turkey

INVESTIGATION OF SKELETON CONSTRUCTION COSTS OF VILLA BUILDINGS WITH DIFFERENT CARRIER SYSTEMS

Keywords: Wood carcass, Steel carcass, Reinforced concrete carcass, Construction cost

Abstract In this study, engineering designs were made using wooden, steel and reinforced concrete conveyance systems of a two-story villa with the same architecture. The cost of the rough construction was compared by subtracting the quantities and discoveries of the calculated projects. When the skeleton costs are analyzed, it is understood that the wooden carrier system is the most expensive solution. It is also clear that the reinforced concrete carrier system is the cheapest method. When the cost analysis results are evaluated at the origin of the skeleton construction; it is determined that reinforced concrete structures are cheaper than steel structures. According to the analysis results; it is clearly understood that the cost of building skeleton is much lower than that of reinforced concrete structures and wooden carcass structures. However, when considering the economic life span of the structures, maintenance costs, recycling characteristics and behavior against depression; it should not be forgotten that steel structure system structures will be more advantageous than reinforced concrete structures.

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Latif Onur U ur, Rıfat Akbıyıklı, Ali Ate

1. Introduction As in every sector, building construction is carried out by using various conveying systems in the construction sector as well. In addition to the factors such as the purpose of use, the place to be built, the number of storeys and the factors such as safety, aesthetics, usage period, function of construction, recycling and cost are important factors in selecting building materials. [1-3] Reinforced concrete is the most important building structure accepted in the world today. Reinforced concrete is a building material formed by using concrete and steel together. The construction period of the reinforced concrete structure is made according to the construction made with steel and wood carrier materials. As the floor weight increases, the weight of the building increases, so a serious foundation thickness is required. Because the steel is not as homogeneous and isotropic as the steel, the error in static calculations is greater. The first investment cost of reinforced concrete construction is the use of crops, which is less than steel and lumber. The reinforced concrete structure affects the environment and quality of life negatively during the production. The negative effect on the production of steel and wood structures is less visible, quick and easy to produce. [4] Steel structures are a more durable construction systems due to their flexibility. The steel, which is light compared to the reinforced concrete structure, is constructed in a much shorter time, it can work in all kinds of weather conditions, these materials are not damaged from water. This reduces labor and time costs. [5] After disasters, repairs and maintenance are made faster and less costly than concrete. Reinforced concrete structures after catastrophe are very costly and time consuming. [6] The structure is called "wooden structure" when the structural system of the structure is constructed from wooden building material. Wood is a light construction material compared to the load it carries and it can behave ductile against earthquake loads. Wood is long-lasting. If you think that reinforced concrete and steel have a life of 100 years, wooden material shows resistance for centuries with routine maintenance of 10-15 years. In addition, the wood has a limited load-bearing power and prevents the construction of multi-storey and wide-span structures. Heat insulation of wood is much higher than concrete. While the coefficient of thermal conductivity of the wood is 0.13-0.20 W / mK, the thermal conductivity of the concrete is 2.5 W / mK. This allows heating in winter with less energy and cooler in summer. [7] The lightness of the wood and its use in thinner sections causes a "buckling" problem. The reason why the wood has lost its mechanical properties over time is to increase the "deflection". Another characteristic of wood is that there is

Investıgatıon of skeleton constructıon costs of vılla buıldıngs wıth dıfferent ...

261

very little "unit strain" between "yield stress" and "break point". Wood is not ductile as steel. The steel can reach up to 20% of its unit elongation after reaching the break point. With this feature, steel structures can consume much more earthquake energy. [8-21]

2. Aim and Method In this study, dimensions, floors, floor class, earthquake zone are the same; it is aimed to compare the skeleton building costs when a two-story villa with different carrier systems is constructed with different carrier systems. Designed as an individually designed villa; reinforced concrete, steel and wooden conveyor systems. The grounds for the construction of two storeyed villas with the same architecture in the project were calculated as ground grade "tight sand" (Ground safety tension = 30 t/m3). A two-storey villa was designed on this ground. Sta4Cad program, steel system and wooden carcass account Sap 2000 and Etabs programs were used for this project. The concrete, steel and wooden "skeleton" quantities of the villa project prepared with the help of the data obtained from the calculations are made. These items are prepared for building elements with different construction systems. These building elements are columns, beams and floors. Reinforced concrete foundation is included also.

3. Structurel Design According to Carrier Systems 3.1. Architectural Information The total floor area consists of rooms with a villa, kitchen, bathroom-wc, entree, balcony and usage area designed as a floor 110 m2. The ground floor plan and a section of the drawn architectural project are given in Fig. 1. and Fig. 2.

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Fig. 1. Architectural Ground Floor Plan

Fig. 2. Architectural Cross Section

3.2. Floor and Basic Properties The basic and ground properties used in the study are designed to be the same. The basic design was checked by determining that the soil safety stress was 30 t/m3 in the ground survey report generated on the ground where the


263

structure was to be constructed. Other information required for basic design is given in Table 1.

Table 1. Ground Information for Reinforced Concrete Foundation

Ground safety tension:

30 t/m3

Local ground class:

Z2

Ground bearing coefficient:

7000 t/m3

The two-storey reinforced concrete, steel construction and wooden carcass structure that are created are designed to be 30 cm radial base. The basic structure created was analyzed in the Sta4-Cad program and the design was continued. The resulting stress distribution in the analysis is given in Fig. 3. Each of the colors resulting from the analysis constitutes one of the safety stress ranges. Table 2. shows the values of the soil safety stresses corresponding to these colors.

Table 2. Colors - Stress Scale

Colors Red

Corresponding Safety Stress Scale (t/m2) 5,47

Orange

4,93-5,47

Yellow

4,39-4,93

Light yellow

3,85-4,39

Green

3,31-3,85

Turquoise

2,77-3,31

Blue

2,77-3,31

Dark blue

2,23-2,77

Navy blue

1,15-2,23

Dark navy blue

1,15

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Fig. 3. Soil Stress Distribution

3.3. Reinforced Concrete Construction Properties The supporting columns were chosen as 25x60 cm - 25x75 cm, pavement thickness 12 cm, beams 25x50 cm. S420 steel is used in construction elements. In the calculations, according to C20 class analysis for concrete, concrete type ductility level of concrete type was chosen as normal. Other information required for the reinforced concrete building model is given in Table 3. Reinforced concrete model created Fig. 4. shows the column application and form plans of reinforced concrete analysis results are shown in Fig. 8. and 9. Table 3. Necessary Information for Reinforced Concrete Structure Model

Floor heights:

2,80 m

Number of floors:

2

Flooring system:

Plaque laying

Building importance coefficient (I):

1

Earthquake Zone:

Class 2

Effective ground acceleration coefficient (A0):

0,3

Conveyor system behavior coefficient (R):

4

fcd (Concrete pressure resistance to be used in calculation):

13000 kN/m2 (C25)

fyd (steel yield strength to be used in the calculation):

365000 kN/m2 (S420)

concrete (Concrete unit volume weight):

25 kN/m3


a

265

b

Fig. 4. Reinforced Concrete Structure Model (a) Reinforced Concrete Floor Plan, b) Reinforced Concrete Structure 3 Dimensional Appearance

Fig. 5. Reinforced Concrete Column Application Plan

266


Fig. 6. Ground Floor Reinforced Concrete Pattern Plan

3.4. Steel Structure Properties The supporting columns HE 240A steel, pavement thickness 10 cm concrete, main and secondary beams HE240A steel were selected. The calculations have selected St 44 steel for steel and because of the wide openings, the weir beams are sized with the main beam size. Other information required for the steel model to be constructed is given in Table 4. The perspective view of the created steel model is given in Fig. 7.

Table 4. Required Information for Steel Structure Model

Floor heights:

2,80 m

Number of floors:

2


1

Earthquake Zone:

Class 2

Effective ground acceleration coefficient (A0):

0,3


267

Fig. 7. Perspective view of steel construction

3.5. Timber Construction Properties In the constructed building model, the dikes were chosen at 10x10cm, the floor thickness was 12cm, the beams and the girders were 10x10 cm cross section. The necessary information for the wooden structure model is given in Table 5. The constructed wooden structure model is shown in Fig. 8. and the column application plan is shown in Fig. 9. Table 5. Information Required for Wooden Construction Models

Floor heights:

2.80 m

Number of floors:

2


1

Earthquake Zone:

Class 2

Effective ground acceleration coefficient (A0)

0,3

Ec (Elasticity Module):

1.00E7 kN/m

concrete (Concrete unit volume weight):

8 kN/m3

268


Fig. 8. Perspective View of Wooden Carcass Construction

Fig. 9. Column Scheme of Wooden Carcass Construction


269

4. Quantity and Cost Analysis According to Structural Carrier Systems 4.1. Quantity and Cost Analysis according to Reinforced Concrete Carrier System The quantity information of the structure constructed with reinforced concrete conveying system, the unit prices of the related works in the structure and the total cost of construction are given in Table 6. (TL shows Turkish Lira)

Table 6. Quantity and Dispersion of Reinforced Concrete System

Unit

Quantity Unit Price (TL) Cost (TL)

Concrete

m3

72

165.15

11,890.81

Mold

m2

341.6

38.43

13,127.68

Accessory (Thin)

ton

5,9

2,440.47

14,398.77

Accessory (Thick) ton

2.3

2,420.14

5,566.32

Total

44,983.58 TL

The total cost of the reinforced concrete conveying system is calculated as TL 44,983.58 .

4.2. Quantity and Cost Analysis according to Steel Construction Carrier System The quantity information of the structure constructed with the steel construction support system, the unit prices of the related works in the structure, and the total cost of the construction are given in Table 7.

270


Table 7. Metrage and Exploration of Steel Construction Carrying System Unit

Quantity Unit Price (TL)

Cost (TL)

Concrete

m3

17.6

165.15

2,906.64

ST44 (HE 240 A)

ton

23.291

2,340

54,500.94

Steel construction

Reinforced concrete foundation m3

33

165.15

5,449.95


1.2

2,420.14

2,904.16

35.48

38.43

1,363.49

Concrete

Mold

m2

Total

67,125.19 TL

The total cost is calculated as 67,125.19 TL when the radial base thickness is 30 cm and the floor thickness is 8 cm reinforced concrete. 4.3. Quantity and Cost Analysis according to Wooden Carcass Carrier System The quantity information of the structure constructed with the wooden carcass carrier system, the unit prices of the related works in the structure and the total cost of the construction are given in Table 8. Table 8. Quantity and Exploration of Wooden Carcass Carrier System Unit Quantity Casualties (%7) Unit Price (TL) Cost (TL) Wooden

m3

54.78

3,834

1,375

84,719.25

Foundation Unit Quantity

Unit Price (TL) Cost (TL)

m3

33

165.15

5,449.95


1.2

2 420.14

2,904.16

12.6

38.43

484.21

Concrete

Mold Total

m2

93,557.59 TL

When "pine timber" is used as wood carrier material, the total cost is calculated as TL 93,557,59 .


271

5. Evaluation As a result of the cost calculations made on the rough construction of the projects prepared with different carrier systems; the production cost of wooden carcass structure is 2 times higher than that of reinforced concrete structure and the cost of steel construction is 1.4 times higher than that of reinforced concrete structure. For the structure based on this study, when the initial investment cost ranking is made in the rough structure, the cost of the wooden carcass carrier system is the highest, the cost of the steel construction carrier system is lower, and the cost of the reinforced concrete carrier system is the carrier system which shows the lowest initial investment cost among them. The cost values obtained for the initial investment as a result of the analysis and calculation of the quantities are presented in Fig. 10.

Fig. 10. Carrier System-Initial Investment Cost Graph In this study, we compared the rough building costs of a two-storey villa with the same architecture using wooden, steel and reinforced concrete conveying systems. In addition to this, a survey has been carried out including the analysis of the service life and maintenance and repair costs of wooden carcass, steel construction and reinforced concrete conveying systems. When economic life span, maintenance costs, recycling characteristics and anti-depressive behavior are considered; If the timber carcass construction is done regularly, it will be prevented from being damaged and worn out and its life will be extended. [21] The

272


maintenance cost in the average 5 years is a value between 518 – 1,240 TL (2017 Unit Price-Wooden Material: Pine Timber) for 100 m2. [22] Although reinforced concrete structures have begun to be built in the near future, it is not possible to compare them with timber structures based on very old buildings. However, it is not thought that the life of reinforced concrete buildings built with today's technology will exceed 100 years. The maintenance-repair cost for reinforced concrete structures other than heavy maintenance is between 81,788 - 92,011 TL (2017 - Actual Price) for 100 m2. [23] Although the initial investment cost of the steel construction is high, it is more economical than a reinforced concrete structure compared to the total cost during the construction life. For a steel structure requiring maintenance and repair, the maintenance and repair cost of the structural element varies between 183,068-305,114 TL (2017 - Total Cost) for 100 m2, except for heavy maintenance, which varies according to the functionality of the structural element. [24] Construction investment costs within the scope of this study; maintenance and repair costs of wooden carcass, steel construction and reinforced concrete structures; Considering the advantages and disadvantages of different carrier systems, the following expressions can be made: In the design of two-storey residence, the service life of the use of wooden carcass structure is extended. However, the initial investment cost and maintenance and repair costs are high. The initial investment cost of steel construction and maintenance and repair costs are less than the wood carcass structure. The initial investment cost of the reinforced concrete construction and maintenance and repair costs are the cheapest among them.

REFERENCES [1]

Turkish Republic Ministry of Environment and Urban Planning 2017 unit price list, http://www.csb.gov.tr/db/donersermaye/editordosya/2017_Yili_Birim_Fiyat_Yen i_20_11_2017.pdf

[2]

Turkish Republic Prime Ministry General Directorate of Foundations 2015 unit price list, https://www.vgm.gov.tr/Documents/duyurular10251.pdf

[3]

Eker A. A., Yıldız Technical University, Design and Material Selection, 2009 http://www.yildiz.edu.tr/~akdogan/lessons/malzemesecim/Belgeler/Tasarim_ve_ Malzeme_Secimi.pdf

[4]

Yardımcı N., Sakarya University, Design of Steel https://www.tucsa.org/images/yayinlar/sunumlar/Sakarya-Sunum.pdf

Structures

273

Investıgatıon of skeleton constructıon costs of vılla buıldıngs wıth dıfferent ... [5]

ahin Y. E., Comparison of Steel System and Reinforced Concrete System in Various Parameters in Residential Architecture, Çukurova University, Master Thesis, Adana, 2011 http://library.cu.edu.tr/tezler/8326.pdf

[6]

“Steel Construction”, Es Konstruction Construction Steel Industry & Bussiness Ltd. http://www.esyapicelik.com/icerik/celik-konstruksiyon.html

[7]

Anadolu Insurance http://anadolurisk.com.tr/tr/analiz-konularimiz/yapiozellikleri/bina-yapi-sistemi/ahsap

[8]

[8] Yeomans D., “Dependability of Wooden Structures Against Depression”, Chamber of Civil Engineers zmir Branch News Bulletin Issue 94, August, 2000

[9]

Betonarme Tarihi 1756-2104; http://mmf2.ogu.edu.tr/atopcu./index_dosyalar/Tarih/BeTarihi.pdf

[10]

The advantages of reinforced concrete, Mkv Book; http://mkvkitap.com/tag/betonarmenin-avantajlari

[11]

http://www.magazininsaat.com/?pages,1371

[12]

ahin Y., ‘’ Steel System and Reinforced Concrete System in Housing Architecture Comparison in Parameters’’ Adana, 2011

[13]

Ak an Construction; http://www.aksanyapi.com/tr_TR/celik-yapi/celik-yapilarinavantajlari/

[14]

Mumcular Construction and Machinery Industry Ltd. https://www.mumcular.com/celigin-avantajlari.html

[15]

https://www.taseronekibi.com/blog/taseron-ekip-hizmetleri/celik-konstuksiyonvilla-bina-ve-cati-yapimi-17.html

[16]

Bayülke N., “Wooden Structures and Earthquake”, Turkish Engineering News Journal, vol. 2001/4 http://www.imo.org.tr/resimler/ekutuphane/pdf/384.pdf

[17]

https://tr.wikipedia.org/wiki/B%C3%BCy%C3%BCkada_Rum_Yetimhanesi

[18]

http://whc.unesco.org/en/list/660

[19]

National Geographic – October 2002

[20]

Asmaz Wooden Frame Structures; http://www.raf.com.tr/urun/asmaz-ahsapkarkas-yapilar/5730

[21]

Asmaz Wooden Frame Structures; http://www.ahsapkarkas.com/

[22]

Sözenler Group of the companies; http://www.sozenler.com

[23]

Inspection of Building Products in Terms of "Service Life", 5. International Advanced Technologies Symposium (IATS’09), 13-15 May 2009, Karabük, Türkiye http://iats09.karabuk.edu.tr/press/pro/01_IATS09FRONTPAGES.pdf

[24]

Comparison of Steel and Reinforced Concrete Structures http://www.tazemuhendis.net/2017/04/celik-ve-betonarme-yapilarinarvard.htm

karsilast

Fatma ÜLKER1 Ragıp NCE2 1

DS General Directorate, Ministry of Forestry and Water Management, Ankara, Turkey 2 Fırat University, Engineering Faculty, Civil Engineering Department, Elazig, Turkey Email: [email protected], [email protected]

OPTIMUM DESIGN OF COMPOSITE STEEL IGIRDER BRIDGES Keywords: Bridge design, AASHTO LRFD, Optimum design, Steel girder

Abstract In this study, the analysis and optimum design of composite steel I-Girder straight bridges were performed by CSiBridge package program. Optimum design of the bridge is made according to the AASHTO LRFD specification. The HL-93 truck in the AASHTO specification is considered as vehicle load. Two-span composite steel I-girder bridge was optimized for the application. The results obtained here are compared with the results of conventional bridge solutions.

Introduction For analysis and design of steel composite I-Girder bridges, either LineGirder solution technique or 3D precise analysis technique is used [1,2]. The CsiBridge package program uses a three-dimensional (3D) finite element analysis technique [3,4]. In this study, the analysis and optimum design of the two-span composite steel I-Girder bridge was carried out with the CSiBridge program. The problem is taken from reference [5]. Steel girder I section dimensions for positive and negative flexure regions are given in Figure 2. These cross-sections are nonprismically defined in the CSiBridge program.

Structure of composite steel I-Girder straight bridges A two-span continuous composite I-girder bridge has two equal spans of 165 ft and a 42 ft deck width. The concrete slab is 9.5 inch thick. A typical 2.75 inch haunch was used in the section properties. Concrete barriers weighing 640 plf and an asphalt wearing surface weighing 60 psf have also been applied as a composite dead load. HL-93 loading was used per AASHTO, including dynamic load allowance. For steel I-girders, A709Gr50 steel with a yield strength of 345 N / mm2 was used.

276

Fatma Ülker, Ragıp nce

Fig. 1. Two-span composite steel plate I-Girder bridge a) Elevation b) Bridge cross-section c) Two spans non-prismatic I-girder

Optimum design of composite steel i-girder bridges

277

Fig. 2. Steel girder I section dimensions for positive and negative flexure regions

Optimization of the bridge In the CSiBridge program it is possible to use the specifications of different countries for bridge design. The American AASHTO LRFD specification was used in this study [5,6]. This specification is transferred to the CSiBridge program as well as the bridge design formulas. In this Study, it is aimed to minimize the weight of the bridge. In the figures given above, the weight obtained by the initial cross section of the bridge provides the limitations of the AASHOT LRFD specifications. In the optimum design of the bridge, stress and displacement limiters are generally dominant. However, limitations have been placed on the cross-sectional dimensions by the specification. As Fig.1. shows, there are four steel girders on the bridge, two on the edge and two on the middle. Again, the cross-sectional areas in Fig. 2. are calculated as: For section 1: A1 = 45847 mm2 For section 2: A2 = 72460 mm2 Since the bridge cross-section is non-prismatic, section 1 and section 2 lengths are; L1 = 80467 mm, L2 = 20117 mm. The W1 volume of a steel I girder beam is calculated as follows:

Since the system has four steel I-girder, the total beam volume is: W = 4 = 4* (Since the density of steel is fixed, no account has been added.)

278


The optimum design problem of the bridge structure can be written as follows: The objective function: " ! ! !

!#

(1)

Subject to the constraints: •

For displacement and stress: $! % $!&'()

*! % *!&'() •

(2) (3)

Cross-section proportion limits: + % ,) -. / ,. /

(4) + ,)

-.0 /

-. % ,. %

120 % 123

(5) (6) (7) (8) (9)

where 45 = area of the I-girder; 5 6 7 85 = the density and length of girder I, respectively; $5 = the displacement of joint i, $5&9:;= its upper bound; 5 = the stress in member i; 5&9:;= the allowable stress; D = girder web depth; < ;= web thickness; < = = flange thickness; >= = width of flanges; >=? = width of compression flange; @A? = moment of inertia of the compression flange of the steel section about the vertical axis in the plane of the web; @AB = moment of inertia of the tension flange of the steel section about the vertical axis in the plane of the web. The optimum design of the bridge is made with the above stress and displacement limiter equations. In design, stress limiters were effective. The calculated stresses in the positive and negative moment regions approach the yield stress upper limit of the material (Figure 3):

279


CD E2 F F GH I J2 F GH K GH I J2 F GH K LM E2 F The AASHTO LRFD specification gives the L / 800 limit for general vehicles in maximum deflection calculations (L = girder span). The calculated deflection in the CSiBridge program did not exceed the maximum allowed deflection value (Figure 4): F

I

N'O

K

Fig. 3. Maximum stresses in positive and negative moment regions

280


Fig. 4. The maximum displacement created by the HL-93 vehicle The cross-sections providing the tensile and displacement limiters are given in Fig. 5. In the AASHTO LRFD specification, the limiter equations given for the cross-section web and flanges are also provided. Here, it should be noted that the stress limiters are effective in the optimum design. It is seen that the displacement limiter is the passive limiter.

Fig. 5. Optimum sections providing stress and displacement limiters

281


The optimum cross-sectional areas in Figure 5 are calculated as follows: For section 1: A1 = 40258 mm2 For section 2: A2 = 61548.3 mm2 The minimum W1 volume of a steel I girder beam is calculated as follows: F Since the system has four steel I-girder, the total beam volume is: P Min W = 4 = 4*44.776 In this way, the weight of the bridge (2.06-1.791) / 1.791 = 0.15 saving is achieved.

Conclusions Non-economical solutions are obtained in classical bridge analysis and design. In modern bridge design, there are optimum solutions. It is possible to obtain an infinite number of solutions with limitations established on the system. Only from these weights, however, minimum weighted design meets our purpose. This way, however, a safe and economical steel bridge design that meets all the limitations can be made. In this study, the minimum weight of the composite steel I-Girder bridge was obtained under the subject specification limiters. Here, only the weight of the steel beams is minimized. Bridge deck weight is ignored for this problem.

REFERENCES [1]

Chen, W. F. Duan L. Bridge Engineering Handbook, CRC Press, 1999.

[2]

American Association of State Highway and Transportation Officials, 2010, AASHTO LRFD Bridge Construction Specifications, Third Edition with Interims, Washington.

[3]

CSiBridge V15-V20, Integrated 3-D Bridge Analysis, Design And Rating, Computers and Structures Inc.

[4]

Caltrans, (2000), Bridge Design Specifications LFD Version, California Department of Transportation, Sacramento, CA.

[5]

James, A. S., Richard, A. M., (2007), AASHTO LRFD Bridge Design Specifications, The University of Cincinnati, 4th Ed.

[6]

Internet : Steel Bridge Design Handbook http://www.webcitation.org/700PIqAGc Last Access: 07.06.2018

Vol.

4:

ISBN 978-83-87480-06-6