alhosn university journal of engineering & applied sciences

ISSN 2076-8516

www.alhosnu.ae

Digital divide: A problem of access or use of ICT: The case of academic institutions in Tunisia Husam-Aldin N. Al Malkawi, Abir Ben Haj Hamida, Rekha Pillai A comparison of general design and load requirements in building codes in Canada and Syria Samer Al-Martini Analysis of soil media containing cavities or tunnels by the boundary element method Omar Al-Farouk S. Al-Damluji, Mohammed Y. Fattah, Rana A.J. Al-Adthami Guidelines for implementing pipeline integrity towards minimization of hazardous accidents with practical and industrial case studies M. El-Gammal (Sr.) H. El Naggar, M.M. El-Gammal (Jr.) Durability of Concrete Structures in Arabian Gulf: State of the Art and Improved Scheme Reem Sabouni Cad and 3D visualization software in design education: Is one package enough? Seif Khiati

ALHOSN UNIVERSITY JOURNAL OF ENGINEERING & APPLIED SCIENCES Volume 3

Number 2

February 2011

ALHOSN UNIVERSITY JOURNAL OF ENGINEERING AND APPLIED SCIENCES

ADVISORY BOARD (in alphabetical order)

Prof. Ghassan Aouad Salford University, UK Prof. Goodarz Ahmadi Clarkson University, USA Prof. Hisham Elkadi University of Ulster, UK Prof. Jamal A. Abdalla American University of Sharjah, UAE Dr. Khaled El-Sawy United Arab Emirates University, UAE Dr. Mohamed Lachemi Ryerson University, Canada Prof. Mufid Abdul Wahab Samarai Sharjah University, UAE Prof. Nizar Al-Holou University of Detroit Mercy, USA Prof. Riadh Al-Mahaidi Monash University, Austrialia Prof. Sadik Dost University of Victoria, Canada Prof. Ziad Saghir Ryerson University, Canada

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ISSN 2076-8516

ALHOSN UNIVERSITY JOURNAL OF ENGINEERING & APPLIED SCIENCES A bi annual, refereed journal published by ALHOSN University - Abu Dhabi - UAE Volume 3

Number 2

February Feb. 2011

Chairman Dr. Nasser Bin Saif Al Mansoori Editor Prof. Abdul Rahim Sabouni Associate Editor Dr. Hamdi Sheibani Members Dr. Adel Kheli Dr. Adnan Husnein Dr. Abdelaziz Soufyane Dr. Naima Benkari

Address: P.O. Box : 38772 Abu Dhabi - UAE Tel. : +971 2 4070700 Fax : +971 2 4070799 E-mail : [email protected] Website : www.alhosnu.ae

Managing Editor Dr. Al Haj Salim Mustafa

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AHU J. of Engineering & Applied Sciences 3 (2) 2011 © 2010 ALHOSN University

CONTENTS Digital divide: A problem of access or use of ICT: The case of academic institutions in Tunisia Husam-Aldin N. Al Malkawi, Abir Ben Haj Hamida, Rekha Pillai

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A comparison of general design and load requirements in building codes in Canada and Syria Samer Al-Martini

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Analysis of soil media containing cavities or tunnels by the boundary element method Omar Al-Farouk S. Al-Damluji, Mohammed Y. Fattah, Rana A.J. Al-Adthami

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Guidelines for implementing pipeline integrity towards minimization of hazardous accidents with practical and industrial case studies M. El-Gammal (Sr.) H. El Naggar, M.M. El-Gammal (Jr.)

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Durability of Concrete Structures in Arabian Gulf: State of the Art and Improved Scheme Reem Sabouni

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Cad and 3D visualization software in design education: Is one package enough? Seif Khiati

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AHU J. of Engineering & Applied Sciences 3 (2) : 7-18 (2011) © 2010 ALHOSN University

DIGITAL DIVIDE: A PROBLEM OF ACCESS OR USE OF ICT: THE CASE OF ACADEMIC INSTITUTIONS IN TUNISIA Husam-Aldin N. Al Malkawi1*, Abir Ben Haj Hamida1, Rekha Pillai1 1

Faculty of Business, ALHOSN University, P. O. Box: 38772, Abu Dhabi, U.A.E.

ABSTRACT: This paper examines the causes of digital divide in a developing country using Tunisia as a case study. The development of information and communication technologies (ICTs) took place exponentially resulting in the emergence of digital divide. A new form of illiteracy is emerging with respect to difficulty of access to information, difficulty of being informed and incapability for initiating innovative approaches. This study focuses on access and use of ICT by instructors in academic institutions in Tunisia. A questionnaire was developed and distributed to 100 instructors in Sfax University (Tunisia), to infer the computer skills of teachers and their use of ICT. It aims to determine the difference in the extent of ICT usage for personal and educational purposes by instructors and the attitude of various stakeholders towards the integration of ICT in education. A discriminant analysis was further employed to interpret the results of the findings. The main finding of this paper is that the problem is more related to the use rather than the access to ICT. Also, the result shows that the majority of instructors acquired only basic skills for the usage of ICT in their teaching. A significant disparity was noticed in the optimum use of ICT in the sense that only a limited percentage of ICT was being devoted for knowledge enhancement, the majority, however, being utilized for social networking. KEYWORDS: ICT, digital divide, Access to ICT, Use of ICT, Tunisia.

1. INTRODUCTION Information Communication Technology (ICT) acts as a corner stone to generate, acquire, preserve, manage, process, display and disseminate information. With the magnitude of their impact on society and particularly in the educational environment, ICTs have the potential to be a radical innovation, revolution or a paradigm shift. The use of ICT by individuals, groups or organizations has particular importance since it is subject to factors relevant to behavior and assessment of individuals. Its application to the higher educational sector and research enables students to update and improve the quality of their knowledge and attain their vision of career enhancement. In Tunisia, development of ICT has evolved as a strategy which aims primarily to make the country technologically competent in order to withstand foreign competition. Thus, we cannot overlook the fact that education plays a major role in the evolution of a country that is committed to achieve global excellence. In this way, the Ministry of Higher Education, Scientific Research and Technology seeks to make ICT more accessible through increased investment, research and training in this area. The integration of ICT in education is dependent on the behavior, qualification and attitudes of teachers. They play the role of intermediary between academic institutions (resources) and students (potential users). For this reason, the sample of our study will be teachers in higher education. This paper is based on an analysis of issues related to ICT access and use within academic institutions in Tunisia. The main aim of the study is to arrive at an answer to the question ____________________________________________ * Corresponding Author. Tel.: +971 4070568, E-mail : [email protected]

* Corresponding Author. Tel.: +971 4070568 E‐mail: [email protected]

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HUSAM-ALDIN N. AL MALKAWI, ABIR BEN HAJ HAMIDA, REKHA PILLAI

pertaining to whether the digital divide is an issue related to access or application. The choice of this issue has been inspired by the importance of the subject since the holding of the 2nd phase of World Summit of Information System in Tunisia and the emergence of ICT subject at lower levels in the Tunisian education system. Moreover, lack of sufficient research in the field of digital divide in developing countries, especially Tunisia, has prompted our current study. The main finding of this paper is that the problem is more related to the use rather than the access to ICT. Also, the result reveals that the majority of instructors acquired only basic skills for the usage of ICT in their teaching. The remainder of this paper is structured as follows. Section 2 reviews some of the previous studies relating to digital divide. Section 3 states the methodology adopted in this study. Section 4 presents the analysis and findings, Section 5 concludes the paper and Section 6 includes the references.

2. LITERATURE REVIEW The digital divide is a new term emerged with the emergence of ICT. It is generally defined as the difference in access between rich and poor countries in term of ICT. It encompasses both the differences in access to technology among individuals and the gap between nations that have and those who do not have the technology [4]. The measurement of digital divide was originally based on traditional quantitative indicators such as internet penetration, number of personal computers and volume of e-commerce. The reason for this gap can be explained in several countries not only by deficiencies in communications infrastructure or low incomes, but also due to the emergence of qualitative factors like illiteracy, culture, and language. A study by Looker and Thiessen [8] addressed a different aspect of digital divide and arrived at the existence of two dimensions in digital divide. The first dimension was related to access to computers and ICT, and the second related to the extent of computer usage at school and at home. Thus it can be concluded that the issue of digital divide is not limited to access to ICT but also to its extent of application. However Renaud and Torres [11] define access to content as a stage separate from access to physical infrastructure. The technology imparts information and what differs from one to the other is access to this information regardless of computer equipment, so the only access to knowledge in this way allows distinguishing those who did not. In addition, developed countries exert great pressure on developing countries to deliver their data reflecting their own characteristics and they overpower these countries by concepts and models of development that may not be applicable to their environment. A further study by Baile and Lefievre [1] noted that the success of ICT is dependent on the understanding of the necessity of its importance and the simplicity of its attributes. So, beyond the digital divide already known and defined in terms of access to ICTs, there is a divide more important that is the quality of ICT use. A gap may exist between users and non users. It can be also among the users as some are intensive users while the others are users of low dose [10].

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DIGITAL DIVIDE : A PROBLEM OF ACCESS OR USE OF ICT: THE CASE OF ACADEMIC INSTITUTIONS IN TUNISIA

Komis [5] and Makrakis [9] based their studies on an analysis of school practices of various developed countries and proposals made by committees of experts and arrived at three models which were related to the introduction and integration of ICT into education systems. The first model considers ICT as a teaching subject. It suggests imparting computer knowledge by considering IT as a separate discipline and promoting a process computer. The second model is the antithesis of the first and considers IT as a tool for teaching and learning in all disciplines and a means to an interdisciplinary approach and integral learning processes. The third model which encompasses the others is a result of the inability of a short-term application of the integrated approach, and the need to have a certain level of literacy, at least currently, concerning the use of the computer. More recently, Lebrun [7] specified three different applications of ICT in education, which were the reactive, proactive and interactive mode respectively. The reactive mode regards ICT as resources for learning and therefore the emphasis is on information extracted from the environment (culture, knowledge etc) that has teachers or sources of knowledge such as media, database, encyclopedias, etc. to impart this information. The related teaching methods here are courses, presentations, lectures and exercise sessions.. The proactive mode specifies the objective from the use of ICT as manipulating the world and its representations. The emphasis is on the cognitive skills (analysis, synthesis, evaluation, critical thinking) that the learner will have to deploy into the environment. It is for the learner to reconstruct, to rediscover through the use of simulations (analysis) and modeling (synthesis) to solve problems and create projects. The main tools employed are programming software, simulation and modeling software, compact disks and websites. The teaching methods which are related to this mode adopt problem solving approaches, project development, the real and virtual laboratories, etc. The Interactive mode aims to use ICT for mutual knowledge sharing. In this mode, the focus is more on interpersonal skills. This can be seen as the conjunction of the two previous modes with different versions of relational interactivity: 1) Immersion in an environment (role playing, interaction with virtual partners) 2) Interaction between distant partners (mail, news, listings and educational uses) 3) Interaction with local partners. The digital pedagogy could be defined as the set of techniques, media and digital means currently being used to optimize the teaching-learning process. This pedagogy as articulated by Bloom [2] predicted that with sufficient time and resources, all students should be able to achieve all the objectives of a course. However, the percentage of failures might be relatively high. All the difficulties mentioned above largely explain why a large proportion of faculty is still very reluctant to integrate ICT in their daily teaching activities, and confined in far more traditional approaches. This is mainly due to lack of supervisors support, professional and technical support for the creation of teaching materials adapted to this new paradigm. The gap also widens due to the lack of studies based on Tunisia.

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3. METHODOLOGY The paper employed qualitative research design and descriptive statistics for the purpose of completing the study. A questionnaire was developed after having been inspired by the research done within the research group on the interdisciplinary in teaching education at the University of Shebrooke, Canada [6]. A pilot study was conducted by testing the questionnaire on a small number of instructors before conducting the main survey for testing errors in structure design and omissions, existence of ambiguity etc. It also helps to understand the extent of understandability of questions framed. Adequate Response categories were developed for questions in order to facilitate the process of coding and analysis. This questionnaire was divided into four main parts. The first part was related to the description of the equipment in the institution and to the respondents' perception of these facilities. The second part addressed the ICT access in education. The third part dealt with the practical use of these tools, both personal and on the teaching practices. The fourth part included 7 items with a response forming an agreement scale in relation to ICT1. The questionnaire was administered personally or by mail to the target sample of 100 instructors from a population of 530 instructors in the year 2007. The instructors belonged to SFAX University, Tunisia. The University encompasses 4 colleges, each specializing in different disciplines namely Natural Science, Social Science, Computer Science and Business. The sample was chosen by quota sampling following Charfi [3] in her study about the attitudes of teachers and researchers towards internet. The data were processed according to the nature of the variables that determine them. Initially, we calculated the structures of frequencies and percentages for all items available for an overview of the study sample and to find out more of its characteristics. Discriminant analysis was later used to determine which continuous variables discriminate between two or more naturally occurring groups. There are several tests of significance, but we only present Wilks' lambda here. Wilks' lambda is used as a test of mean differences in Discriminant Analysis, such that the smaller the lambda for an independent variable, the more that variable contributes to the discriminant function. Lambda varies from 0 to 1. The F-test of Wilks' lambda shows which variables contributions are significant. The aim was to study the relationship between a qualitative variable and a set of quantitative variables and to find out the most discriminating variables in order to investigate if they are related to the access or the use of ICT.

1

The questionnaire is available upon request.

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4. ANALYSIS AND FINDINGS This section will be devoted to the presentation and analysis of data collected by questionnaire at the survey which focuses on best practices for access and use of ICT in academic institutions. Firstly, we try to present frequencies calculated for different items in the questionnaire by using descriptive analysis. Secondly, we consider sex, age, rank and experience of instructors as independent variables and the below factors as dependant variable: 1) Use of audiovisual support 2) Possession of a computer at home 3) Possession of a computer in the office 4) Number of Internet connections per week 5) Number of use of emails per week 6) Mode of learning to use ICT 7) ICT Training 8) Use of communications software 9) Use of common software. These variables represent the practices of access and use of ICT by instructors in academic institutions. A positive response was received from 81 teachers out of the 100 questionnaires distributed. The whole survey was grouped under several headings such as the qualitative attributes of the respondents, description of ICT equipments in the institutions, access to ICT in education, use of ICT by teachers and the personal attitude towards ICT in education. 4.1 Findings on the qualitative attributes of the respondents The questionnaire began with general questions focusing on the gender, age, qualifications, and the title held in the Institution. This was to generalize the qualitative features of the respondents to arrive at conclusions whether these qualitative traits had any impact on the concept of ICT (Table 1).

Table 1. Demographic Specifications Gender Male Female Total Age group 26 -30 31-40 41-50 51 plus Total

Frequency 60 21 81

Percentage (%) 74.1 25.9 100

6 26 38 11 81

7.4 32.1 46.9 13.6 100

Table 1 reports that males constituted 74.1% and females constituted 25.9% of the respondents. The most active participation of 46.9% was from instructors belonging to the age group between 41 and 50 years of age.

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This was solely due to the fact that the majority of the teachers had more than 10 years experience in the educational field. Thus they automatically fell under the title of Assistant, Associate or Full Professors. Table 2 revealed that 38.3 % of the respondents had a teaching experience between 11-20 years. These qualitative attributes signals that majority of respondents were experienced in the field of education and were resorting to the olden methods of teaching as the ICT revolution is a term more familiar to the new generation. Table 2: Rank and Experience of Teachers Rank Professor Associate Professor Assistant Professor Instructor Total Number of years Less than 5 6-10 years 11-20 years 21 years and above Total

Frequency 8 10 32 31 81

Percentage (%) 9.9 12.3 39.5 38.3 100

8 19 31 23 81

9.9 23.5 38.3 28.4 100

4.2 Findings on ICT equipments in the Institutions This section mainly dealt with questions related to the availability of hardware and software in the institutions as they were the prerequisites for the successful adoption of ICT. The findings on these aspects are reported in Table 3. Table 3: Availability of ICT

Is the library computerized

Access to computers

Existence of website

Frequency

Percentage (%)

Positive

58

71.6

Negative

23

28.4

Total

81

100

Positive

51

63

Negative

30

37

Total

81

100

Positive

62

76.5

Negative

19

23.5

Total

81

100

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The first question put forth in examining the issues in ICT was if the institutions had a computerized library. 71.6% of the teachers reassured the above statement whereas 28.4% denied this fact. This meant that students had an option to widen their knowledge base in computers from the libraries. We can see that 63% of the teachers had accepted that they had access to computers while 37% did not. This was because only teachers with titles of associate and above were provided with a computer in their office. With regard to the question related to the existence of a website for their institution a positive response was received from 76.5% of the teachers. The remaining 23.5% teachers belonged to the Faculty of Humanities, which did not have a website of their own. This clearly reveals that the computerization was in progress and being adapted for enhancing information content. An opportunity to evaluate certain options such as the adequacy of computers, its power, and availability of software, networking of computers, speed and stability of internet connections provided a mixed response, the findings of which are shown in Table 4. Table 4: Results Summary of Responses from Teachers (Availability of ICT) Strongly disagree

Adequate number of Computers Computers are powerful Software is updated Computers are networked Fast Internet connection Internet connection is stable

Disagree

Agree

Strongly agree

Freq 9

% 11.1

Freq 38

% 46.9

Freq 28

% 34.6

Freq 6

% 7.4

6

7.4

41

50.6

26

32.1

8

9.9

13

16

33

40.7

28

34.6

7

8.6

1

1.2

26

32.1

33

40.7

21

25.9

5

6.2

19

23.5

42

51.9

15

18.5

8

9.9

20

24.7

38

46.9

15

18.5

Table 4 shows that more than 50% of the instructors expressed their dissatisfaction with the availability of computers, its power, and the non adoption of latest software. Nearly 50% of the teachers expressed satisfaction over the speed and stability of internet connections available to them. This proves that if the teachers are provided with adequate computers with sophisticated technology, there will be a positive and remarkable enhancement in the usage of ICT. 4.3 Findings on ICT in Teaching In order to explore the perceptions related to wider access to ICT in education, questions pertaining to the usage of computers in disciplines other than computer science were

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administered to the subjects under study. An impressive response of 87.2% was received from respondents agreeing to the possibility of usage of IT in all disciplines. This reveals that ICT can be innovatively applied in all disciplines to ensure effective learning. The above response rate opens venues for further research regarding the extent of readiness to adopt ICT in education. The teachers were also asked to air their opinion on the favourability of inculcating digital technologies in education, the result of which is shown in Table 5. Table 5: Usage of ICT Opinion Indifferent Favourable Unfavourable Total

Frequency 3 44 34 81

Percentage (%) 3.7 54.3 42 100

Table 5 reveals that nearly 54.3% were highly favouring the application of ICT in education and only a negligible rate of 3.7% of the respondents showed a neutral attitude towards the ICT. This can be attributed to age, subjective approach or the normal tendency to resist change. Another barrier in the implementation of ICT was the non availability of internet connections in classrooms which hampered the posting of the course material online. It also outlines the ignorance related to the application of ICT for enhancing the educational sector. Questions were also asked regarding the audio visual method used in class and 38.3% of the respondents admitted using the old fashioned overhead projector while 35.8% of the instructors refrained from using any audio visual aids. The teachers were asked to voice their opinion on what they considered the main obstacle to the use of ICT in education. Majority of the respondents attributed this hindrance to the lack of training imparted to instructors regarding the use of ICT. The second prominent factor accelerating the pace of hindrance was the inferior quality of existing equipments which were basically non user friendly. Teachers also expressed their concern over the lack of necessity to integrate the ICT in the curriculum. Of the few solutions offered to the teachers to overcome the obstacles, all of them substantiated the necessity of the provision of adequate computers as the primary step to mitigate this digital gap and emphasised the importance of making the educational content suitable and available for classroom use through ICT. These results underline the fact of non availability of adequate equipments, lack of proper training and support and the non integration of ICT methods in teaching as the major facts widening the digital gap in Tunisia. 4.4 Findings on Personal Use of ICT The survey on the extent of usage of ICT by teachers revealed 42% of respondents agreeing to the fact that they used computers more in their place of work rather than at home. 58% of them operated the computers both at home and at work. Questions were also administered

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about the number of internet connections in a week and the frequency of email usage. A consistent response was reported on the frequency of email usage and internet browsing a week. This validates the fact that the internet was connected for the sole purpose of sending mails. This proves that the teachers have not taken their initiative for self advancement and there is a non existence of ICT based homework. In terms of the mode of training received in relation to the use of ICT a diverse profile emerged from the sample. Several modes of training such as routine training, specific training, self study and help from colleagues and friends were put forth for choosing. The results obtained for this question is shown in Table 6. Table 6: Mode of Training Mode Undergone Routine Training

Frequency 18

Percentage (%) 22.2

Undergone a specific training

13

16.0

Self study Colleagues and friends Total

24 26 81

29.6 32.1 100

Table 6 shows that 22.2% of the teachers gradually got acquainted with the ICT in their routine training period, 32.1% of the teachers confessed that they were trained by their colleagues while 29.6% underwent a self study. A startling percentage of 96.3% invalidated the act of participating in a training course that focussed specifically on the educational use of ICT. This clearly evidences the fact that there is absolutely no impetus from the part of the institution to enhance ICT skills. The respondents were also given an option to rate their awareness in ICT and 14.8% of the respondents assessed themselves as beginners and 37% of them marked themselves as average with respect to the use of communications environment (that is the usage of internet, emails etc). 9.9% of the teachers rated themselves as excellent and 2.2% expressed total unfamiliarity with the ICT. With regards to the usage of standard software like word, excel etc 11.1% the respondents rated themselves as experts. This shows that the majority teachers met the minimum criteria in order to satisfy the requirements of achieving a threshold in computer literacy. Empowering them and initiating changes would bring phenomenal changes in the usage of ICT. 4.5 Findings on the personal attitude towards ICT The questionnaire finally concluded with questions relating the personal opinion of teachers regarding their approach to the current use of ICT in their institutions. Various questions were put forth relating to the different fields in which ICT was being implemented from an individual purview. The results of the answers received from these questions are summarised in Table 7.

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Table 7: Results Summary of Responses from Teachers (Usage of ICT) I like to use the computer to prepare course materials. I found that using the Internet facilitates the realization of my lesson plans. When I am in class, the computer is part of my routine teaching tool. The computer is essentially a means of communication (electronic mail). The computer is essentially a means of distraction The computer is essentially an instrument of work outside the classroom context (information retrieval, preparation of course). The use of ICT in education is justified in institutions in science or technology and not in other institutions.

Strongly disagree (%)

Disagree

Agree

(%)

(%)

Strongly Agree (%)

6.2

25.9

43.2

24.7

9.9

34.6

30.9

24.7

22.2

51.9

19.8

6.2

3.7

23.5

59.3

13.6

12.3

66.7

19.8

1.2

3.7

24.7

51.9

19.8

61.7

35.8

0

2.5

The survey on the attitude to ICT in education attained positive responses. According to survey results, we note that 67.9% of teachers surveyed agreed on the preparation of materials for teaching using the computer. However, only 55.6% said that surfing the Internet facilitated the preparation of the course. In addition 74.1% of teachers surveyed said that IT did not occupy a part of their everyday teaching tool. The computer was essentially a communication medium for 72.9% of subjects and did not pose as a means of distraction for 79% of teachers. It also served as an instrument of work outside the class for 71.7% of respondents. Finally, almost all respondents admitted that the use of ICT cannot be justified only in sciencebased institutions. These results arrived at the fact that ICT was only utilised for sending emails which in turn reaffirmed its stand as a communication tool. The Wilks’ lambda test proved that the effect of gender, age, rank and experience of the teachers, were not related to the usage of ICT. The discriminating variables were "number of Internet connections per week", "number of email use by week," "learning mode", "the use of communications software" and "the use of common software". Thus we can conclude that the differences among instructors arise due to the differences in the method of using ICT. 5. CONCLUSIONS AND RECOMMENDATIONS The purpose of this research was to explain the causes of digital divide in the academic institutions in developing countries using Tunisia as a case study. Our main objective was to clarify if it is due to a problem of access or use of ICT. A survey was conducted among a sample of 100 instructors from the Sfax University with a response rate of 81 percent. 10

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It follows from this survey that the majority of instructors have developed a minimum level of skills to use computers. Regardless of academic rank, they meet the criteria defining the functional computer literacy, so they are able to use common office software (Word, Excel and PowerPoint) and to use the Internet (surfing and communicating). Moreover, the majority of these instructors were self trained or trained by colleagues and few received professional training. Therefore, we can conclude that providing adequate training programs can upgrade the level of integration of ICT in education. The study showed that most respondents had a computer, both at home and at work and were mainly users of office software. They generally used multimedia technology (e-mail or Internet) for private purpose and for widening access to sources of information for their respective course. Regardless of the gender, age, rank and experience of the teachers, we found significant differences in relation with the use of ICT in teaching. The discriminating variables were "number of Internet connections per week", "number of email use by week," "learning mode", "the use of communications software" and "the use of common software". Thus, we can conclude that the differences among instructors arise due to the differences in ICT usage. The Tunisian government provided sufficient infrastructure and an environment conducive for the integration of ICT in education. However there is a strong trend towards the establishment of E-education. Consequently, it is a question of willingness from the instructors to successfully integrate these new technologies in the education process. The effectiveness of these technologies depended primarily on ability and willingness of stakeholders in the academic field. In this sense, the emphasis here is on human capital. So we can conclude that these problems are with the use of ICT rather than access. Finally, we argue that emphasis should be provided on training the faculty for updating them with the latest technology used in institutions. A strategic alliance with technological experts can prove beneficial for the institutions as they can benefit from the expertise provided by the companies who are adept in latest technological developments. A new curriculum encompassing the imperativeness of the application of ICT in routine teaching can be framed. Policies can be implemented which necessitates the adoption of ICT by institutions in order to attain ministry recognition. Limitations arise in this study due to the limited time period and sample used in this research. Therefore suggestions for future research centres around the adoption of a longer time period and larger sample. This paper which used Tunisia as a case study can be replicated in the educational environment of other developing countries in order to examine the existence of digital gap and the major factors contributing to this gap in these countries and to see whether they face similar issues concerning ICT.

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6. REFERENCES [1]

Baile, S. and Lefievre, V. (2003). "The successful use of email - a study of its determinants within a production unit of aircraft maker", 8th conference of AIM, Grenoble. [2] Bloom, B S. (1968). Learning for mastery, Evaluation Comment. (UCLA-CSIEP), 1(2), 112. [3] Charfi, A. (2004). "Attitudes of teachers’ vis-à-vis ICT", Working Paper, FSEG SfaxTUNISIA. [4] Gurova, E. (2001). "The Digital Divide - A Research perspective.” Seville, IPTS. [5] Komis, V. (2001). "The information technology and communications in the Greek educational system: the difficult path of integration," Journal of Education and Public Information, No. 101. [6] Larose, F. (1999). "The information technology and communication in university teaching and training teachers: Myths and Realities," Journal of Science Education: Perspectives of Future Education, Volume 27, No. 1 [7] Lebrun, M. (2002). "Theories and methods for teaching and learning: Which place for ICT in Education", De Boeck, Bruxelles-Paris. [8] Looker, D. & Thiessen, V. (2003). "The digital divide in Canadian schools: factors that affect access to information technologies and their use by students", Working Paper, No. 81-597 -XIE. [9] Makrakis, V. (1988). Computers in Education, Studies in International and Comparative Education, Stockholm International Education. [10] Reddick, A., Boucher and C., Groseilliers, M. (2000). "The Dual Digital Divide: The Information Highway in Canada", Public Interest Advocacy Center, Ottawa. [11] Renaud, P and Torres, A. (1996). "lnternet, a chance for the South", Diplomatic World, p 6.

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A COMPARISON OF GENERAL DESIGN AND LOAD REQUIREMENTS IN BUILDING CODES IN CANADA AND SYRIA Samer Al-Martini*

College of Engineering and Computer Science, Department of Civil Engineering, Abu Dhabi University, Abu Dhabi, UAE

ABSTRACT: This paper aims at comparing the Syrian and Canadian codes used for design and execution of reinforced concrete building structures. Primarily, the Arabic Syrian Code for Design and Execution of Reinforced Building Structures, 2004 (ASC, 04) has been studied and compared with both the National Building Code of Canada (NBCC) for loads specification and the Canadian Standard Association Code (CSA A23.3) for reinforced concrete specification. The study revealed that the Syrian code has increased the “factor of safety” by recommending higher values of load factors where, the factored dead load and the live load are almost 20% less in Canadian code than that in Syrian code due the difference in the dead and the live loads magnification factors. KEYWORDS: building codes, load factors, factored resistance, live load demand, nominal resistance

1. INTRODUCTION The Arabic Syrian Code for Design and Execution of Reinforced Building Structures (ASC) [1] is adopted in Syria for designing a building. In Canada, the National Building Code of Canada (NBCC A23.3-04) [2] for loads specification and the Canadian Standard Association Code (CSA A23.3) [3] for reinforced concrete specification are used for designing buildings. The Syrian and Canadian codes share the basic rationale, and have many common features. They contain general requirements for safety, serviceability, and structural integrity. It may be worth presenting a brief historical review of both codes and how they were developed and modified over years. The constitution in Canada gives each province the responsibility for setting its own building construction regulation. In a few cases the provinces have given the municipalities the historic right of writing their own building codes. As such, in the early years, regulating building construction in Canada was done by patch working of building codes across Canada. The National Building Code in Canada was first published in 1941 by the federal government. This code was later adopted by the various provinces and municipalities in Canada during the next 20 years. Since 1960, The National Building Code of Canada has been revised about every five years up to 1995. However, the 2000 edition of the building code was taken considerably longer time than what was expected and the next edition of the National Building Code of Canada was published in 2005. The available 2005 edition of the National Building Code of Canada (NBC) has over 800 technical changes. The 2010 National Building of Canada Codes was published on November 29, 2010. _____________________________ * Corresponding Author. E-mail : [email protected]

1

19

SAMER AL-MARTINI

The Syrian code has been modified over time as well. The second edition of the Syrian code was issued in 1995 and then was followed up with three appendices in 1996, 1997, and 2000; these appendices provided specifications for building design against earthquake. The second edition along with its appendices has provided the Syrian civil engineers with the necessary aids required for designing anti-seismic structures. However, during implementing the second edition of the code, it was realized that the code needs to be modified in order to account for the rapid advancement in computer technology and the continuous development of structural software. Moreover, it has become necessary that the code covers steel structures as well. Therefore, the third edition of the code was published in 2004 along with 14 appendices to account for the abovementioned aspects.

2. COMPARISON BETWEEN THE SYRIAN AND CANADIAN CODES 2.1 Structural Load Specifications Dead Loads This term includes the weight of the member itself, and the weight of all members permanently supported on this member such as partitions and appliances. Partition loads used in the design shall be shown on the drawings. The calculation of the dead load in both codes follow similar concepts taking into consideration the type of material used in each case with its unit weight. The basic difference between the two codes is in the magnification factor used for the dead loads. In the ACS the dead load is multiplied by a factor of 1.5 while it is multiplied by 1.25 in the NBCC. Live Loads The live loads on an area of floor or roof depend on the intended use of the particular structure. Table 1 shows a comparison between the uniformly distributed load patterns taken from Table 5.2 and Table 4.1.5.3 in Syrian and Canadian Codes [1,2], respectively. Table 1- Live loads specification in ASC and NBCC codes Codes

bedrooms (KPa)

Stairs (KPa)

Roofs (KPa)

LL Reduction Factors

ASC NBCC

2 1.9

3 1.9

1 1

1.8 1.5

2

20

A COMPARISON OF GENERAL DESIGN AND LOAD REQUIREMENTS IN BUILDING CODES IN CANADA AND SYRIA

Snow Loads In the ASC the snow load is taken considering the elevation from the sea level [1]. The ASC would require that snow load on a roof of an ordinary building in Damascus region to be taken as 1 KPa [1]. In NBCC the snow load on a roof is determined considering the product of a ground snow load (determined from a map) over 30 years and a ground to-roof conversion factor [2]. The NBBC would require that the roof of an ordinary building to be designed for a snow load of 2 KPa. The difference between the two values is a logical reflection of the difference in weather conditions between the two regions. Wind Loads In the ASC the pressure exerted by the wind on an ordinary building with low height ⎛ height ⎞ < 4 ⎟ is taken only as a static horizontal uniformly distributed load according to the ⎜ ⎝ width ⎠ following equation: (1) P = C p C e k s q (KPa)

Where, Cp is the sum of the pressure coefficients related to the surface roughness and number and its values is taken from Table 5.5 from the ASC [1]. Ce is a coefficient related to building height from the ground surface. This factor accounts for the increase in the wind velocity with height. It is calculated according to the following 42 equation: (2) Ce = 1 − h + 60

ks is a coefficient related to the location of the building in terms of its exposure to wind and it is taken from Table 5.6 in the code. q is the reference velocity pressure in KPa, and it is defined as the pressure due to wind excreted on a flat plate suspended at 10 m above the ground surface. It is calculated according to the following equation: q = V 2 / 1630 (3) Where, V is average wind velocity (m/s) In the NBCC the wind load is calculated according to the following equation: p = qC e C g C p

(4)

Where, q is calculated according to the following equation: q = 0.5ρV 2

(5)

Where, ρ is the air density during the windy period of the year and its values are tabulated in Appendix C2-12 of NBBC [2], V is hourly average wind velocity.

3

21

SAMER AL-MARTINI

Ce is the exposure facto and it is. It is calculated according to the following equation: 0.2 ⎛ hi ⎞ Ce = ⎜ ⎟ (6) ⎝ 10 ⎠ Cg is the gust factor; it accounts that when gusts blow they may have velocity greater than that of wind. In the simplified method, this term is taken as 2 for the design of building as whole. It should be noted that this term is not considered in the ASC for the calculation of loads due to wind. Cp is the external pressure coefficient. This factor is given in Commentary B2-17 of the NBCC for various shaped building [2]. Load and General Design Requirements for Canadian and Syrian Codes The load requirements in both codes are similar in their rationale but different in their specifics. The load combination in the ASC is calculated according to the following equation: U = 1.5DL+ 1.8LL (7) In the NBCC the ultimate load is calculated according to the following equation: U = 1.25DL + 1.5LL (8) Where, DL refers dead loads and LL refers to live loads. 2.2 Structural design specifications

Flexural Design of a beam Both codes i.e, ASC and CSA A23.3, follow the ultimate limit state philosophy for designing flexural members. In the ASC code the maximum strain of concrete (έcu) in stress block (Fig. 1) is 0.003 , while it is taken equal to 0.0035 in the CSA A23.3. Moreover, the stress in stress block is taken as 0.85f’c in the ASC and it is taken as α1f’c in the CSA A23.3. In the ASC the stress block depth (a) is: a=0.85C (9) In the CSA A23.3 the depth of stress block is calculated using the following equation: a=ß1C (10) Where, C is the depth of neutral axis ß1 = 0.97-0.0025f’c ≥ 0.67 (11) έcu

0.85f’c a

C d

H

Axis of zero strain

As fy

b

εs ≥ εy

Figure 1- Stress block for a beam

4

22


In the ASC the strength reduction factor Ω is used to account for the possible variations in dimensions of concrete section and placement of reinforcement and other miscellaneous workmanship items and it is equal to 0.9, 0.7, and 0.85 for bending, axial compression, and shear and torsion, respectively. Thus, the reduced nominal flexural strength (Mr) is calculated according to the following equation: a⎞ ⎛ (12) M r = ΩAs f y ⎜ d − ⎟ , (Ω = 0.9) 2⎠ ⎝ In the CSA A23.3, the factored concrete compressive strength used in checking ultimate state shall be taken as φ c f ' c (øc = 0.65) and the factored strength of steel reinforcement is øs = 0.85. a⎞ ⎛ (13) M r = φs As f y ⎜ d − ⎟ , ( Φs = 0.85) 2⎠ ⎝ a⎞ ⎛ Where, M n = As f y ⎜ d − ⎟ (14) 2⎠ ⎝ Shear design of a beam The shear due to the applied loads on a beam is usually calculated at a distance d from the inner face of the support in both codes CSA A23.3 and ASC. A simplified approach, in which the angle of shear cracks is considered to have a 45o with the horizontal line, is used in the ASC. In CSA A23.3 there are two methods namely the Simplified Method and the General Method. The Simplified Method is used for flexural members without significant axial tension. The basic design equation for shear capacity of slender concrete beams in both codes is: Vr ≥ V f (15)

Where, Vf is the shear force due to the factored loads and Vr is the factored shear resistance given by: Vr=Vc+Vs (16) Where, Vc is the shear carried by concrete and Vs is the shear carried by the stirrups. The shear carried by concrete (Vc) is calculated according to the following equations: In the ASC: ⎛ Vf d ⎞ ⎟bw d ≤ 0.3 f ' c (MPa) Vc = ⎜ 0.16 f ' c + 18ρ w ⎜ ⎟ M f ⎠ ⎝ Av f y d S= (V f − Vc ) In the CSA A23.3: ⎛ V d⎞ Vc = ⎜ 0.158 f 'c + 17.2 ρ w f ⎟bw d ⎜ M f ⎟⎠ ⎝

5

(MPa)

(17)

(18)

(19)

23

SAMER AL-MARTINI

Where, ρw is longitudinal steel reinforcement ratio, bw is width of web of member and Mf is applied moment at a section due to factored loads. A f d (20) S = φs v y (V f − Vc ) Where, S is stirrup spacing (mm), Av is area (mm2) of stirrup reinforcement within a distance s, and øs =0.85 is the resistance factor for reinforcing steel.

Design of Columns

The figure below shows a given strain distribution for a loaded column adopting the ASC .

0.85 f’c

0.003

A’s

ε'si

A’sf’s 0.85A’cf’c

εsj

As

Asfs Figure 2- Stress block for a column in ASC In ASC, the strength of a column under truly axially loading is calculated as: Pr o = Ω 0.85 f ' c (Ag − Ast ) + f y Ast

[

]

(21)

Ω = 0.7 (axial load) Ag = gross area of the section (concrete + steel) = yield strength of reinforcement fy = total area of reinforcement in the cross section Ast To account for the un-expected moment, the code specify that the maximum load in column must not exceed: Pr ,max = 0.8Pro for tied column.

Pr ,max = 0.85Pro for spiral column. The figure below shows a given strain distribution for a loaded column according to CSA A23.3: 0.0035 α1f’c A’sf’s A’s α1 A’cf’c ε' si

As

εsj

Figure 3- Stress block for a column in CSA A23.3

6

24

Asfs


The strength of a column under truly axially loading is [4]: Pr o = φcα1 f 'c (Ag − Ast ) + φs f y Ast (22) α1 f’c= maximum concrete stresses φc , φs = material strength reduction factors To account for the un-expected moment, the code specifies that the maximum load in column must not exceed: Pr ,max = 0.8Pro for tied column.

[

]

Pr ,max = 0.85Pro for spiral column.

Thus, it can be observed that the differences between the two codes are in taking the maximum concrete stresses (stresses block) and in the material reduction strength.

Design of slabs

The thickness in ASC of a slab can be calculated from a table based on the type of a slab (one way or two ways) and its dimensions. For a regular building having LL ≤ 5KN/m2, the moment distribution on each slab can be calculated using one of the following methods: The Moment Distribution Factors Method, where the distribution factors on each slab spans are obtained from tables considering the location of each slab. (23) M a = α A wa 2 Where, Ma is the moment on short span of slab, aA is moment distribution factor, w is factored load, and a is the short side dimension. The same equation is applied for the other span of the slab (long span) with different moment distribution factors and span dimension. The Strip Method considering interior or exterior support for negative and positive moment. The factored static moment of a rectangular slab can be calculated: 2 M o 2 = μ 2 wL2 (short span (L2)) (24) M o1 = μ1 M o 2 (long span (L1)) (25) L2 . L1 Negative moment and exterior support: ML1= 0.3Mo1, and ML2=0.3Mo2. Negative moment and interior support: ML1= 0.6Mo1, and ML2=0.6Mo2. Positive moment: ML1= 0.75Mo1, and ML2=0.75Mo2. Reinforcement is designed for the moment considering the section is rectangular. The thickness of a slab in CSA A23.3 is calculated using equations specified in the code for different cases. The Direct Design Method can be applied if the following conditions are satisfied [4]: long span Max ≤ 2 (measured centre to centre of supports) . short span The column offsets are less than 20% of the span.

Where, µ1, µ2 are factors obtained from a table considering μ =

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SAMER AL-MARTINI

There is a minimum of spans in each direction is three. The factored live load must not exceed two times the factored dead load. The total static moment for each slab is calculated using the following equation: w f l2a l 2 n Mo = 8

(26)

Where, wf is factored load per unit area; ln is clear span between columns; and l2a is transverse width of strip. This moment is distributed on the beams and slab spans using factors given in a table provided by the code (CSA A23.3). It should be noted that reinforcement in both codes is designed for the moment considering the section as a rectangular beam. 3. SUMMARY AND CONCLUSIONS

The paper attempted to investigate the differences in general design and load requirements in Building Codes in Canada and Syria used for the Design and Execution of Reinforced Concrete Building Structures. The Arabic Syrian Code for Design and Execution of Reinforced Building Structures (ASC) is used in Syria to design a building while, in Canada, the National Building Code of Canada (NBCC) for loads specification and the Canadian Standard Association Code (CSA A23.3) for reinforced concrete specification are used for designing a building. The paper showed that the Syrian code has increased the factor of safety by adopting higher values of load factors. Also, the live loads for rooms and stairs in the ASC are higher than that specified in NBCC. It can be argued that the ASC is more conservative than the NBCC which is likely due to the fact that Syria lies on an active seismic zone. 4. REFERENCES

[1] [2] [3] [4]

8

ASC, Arabic Syrian Code for Design and Execution of Reinforced Building Structures. (2004) NBCC, National Building Code of Canada. (2007) CSA A23.3, Canadian Standard Association Code. (2003) MacGregor, G. J., and Bartlett, F. M., Reinforced Concrete Mechanics and Design, 1st ed, Prentice Hall Canada Inc. (2000)

26


ANALYSIS OF SOIL MEDIA CONTAINING CAVITIES OR TUNNELS BY THE BOUNDARY ELEMENT METHOD 1. 2. 3.

Omar al-Farouk S. al – Damluji1, Mohammed Y. Fattah*2 Rana A. J. al-Adthami3

Former Professor, Civil Eng. Dept., College of Eng., University of Baghdad, Iraq. Assistant Professor, Building and Construction Engineering Department, University of Technology, Baghdad, Iraq. Former graduate student, Civil Eng. Dept., College of Eng., University of Baghdad, Iraq

ABSTRACT: In the design of tunnels to be constructed in urban areas, it is necessary to estimate the magnitude and distribution of the stresses and settlements that are likely to occur due to a particular design and construction technique. The main factors that greatly affect the stresses and deformations around tunnels and underground excavations are the shape, dimensions, depth of opening below the ground surface, distance between the openings and the kind of supports. In this paper, a study of the effect of different parameters was conducted by considering a cavity of 4 meters diameter under a constant surcharge load of 50 kN/m2. These parameters are: 1. depth below the ground surface Zo, 2. eccentricity of a cavity locations from the centerline of surface loading, and, 3. distance between cavities K. A computer program for analysis by the boundary element method is used for the determination of the stress and deformation fields around two cavities with the above mentioned parameters. The soil is assumed to be homogeneous, isotropic and a linearly elastic medium containing two openings. It was found that a marked increase of stresses takes place as the cavity approaches the ground surface and the stress distribution is very sensitive to the depth variation compared with the case of no-cavity condition. The maximum stresses occur at the haunches of the tunnel rather than at the crown. The vertical displacement of the soil medium increases by decreasing the distance between the adjacent openings. In general, small values of K/D ratios (where K is the distance between two cavities and D is the diameter of one cavity) should be avoided to hinder rapid increases in the stress concentration. KEYWORDS: Boundary element, Soil, Cavity, Tunnel. C

1. INTRODUCTION The boundary element method (BEM) has become one of the most powerful tools for the numerical study of different engineering problems. The comparison of the main features of this method with those of the finite element method (FEM) has occupied many pages in the specialist literature sine the initial development of BEM. An important feature of the BEM is that the functions that represent essential and natural boundary conditions (potential and flux in potential theory and displacements and stresses in elasticity theory) which are the basis of the method, consequently being approximated in an independent form, their coordinates remaining as independent variables of the formulation. In spite of non-symmetric and fully populated character of the matrices associated to BEM, it must be pointed out that the size of the system of equations, defined by the stiffness matrix K, is always smaller than in the finite element method (FEM) approach, for a similar __________________________ * Corresponding Author. E-mail : [email protected]

27

OMAR AL-FAROUK S. AL-DAMLUJI, DR. MOHAMMED Y. FATTAH, RANA A.J. AL-ADTHAMI

degree of dicretization. The ratio between the sizes of the matrices in the two methods will depend on the geometry under consideration, and in particular on the proportion of the boundary (area in 3D and length in 2D problems) to the domain (volume in 3D and area in 2D problems). The smaller this proportion (the greater the domain covered by a certain boundary), the greater the ratio between the size of the matrices of FEM and BEM (the more favourable the use of BEM), [4]. 2. ANALYSIS USING THE BOUNDARY ELEMENT METHOD Although the finite element techniques have been used in so many practical problems, the boundary formulations appear as an alternative technique that, in many cases, can provide more reliable or economical analysis. Even with automatic mesh generation techniques, the finite element method has not found widespread application to tunneling problems because of the data preparation problems and considerable computer time requirements. The input data requirements of the boundary element method are considerably less than these of the finite element method since only the boundary need to be discretized. Unlike the FEM, the BEM can model the boundaries at infinity without truncating the outer boundary at some arbitrary distance from the region of interest. After the numerical treatment of the integral equations, we end up with a system of equations. In contrast to the FEM, the coefficient matrix is fully populated and unsymmetrical. Standard Gauss elimination can be used but, for large systems, the storage requirement and the computation times may be reduced considerably by iterative solvers, such as conjugate gradient methods. Here we also find that the method is “embarrassingly parallelisable” i.e. that excellent speed up rates can be achieved with special hardware. The primary results obtained from the analysis are values of displacement or traction at the boundary depending on the boundary condition specified. In contrast to the FEM, primary results do not include values in the interior of the domain but these are computed by post-processing, [2]. 2.1 Boundary Element Equations Isotropic field problems have a governing equation. From the mathematical analysis, the corresponding boundary integral equation with respect to a source point (xi, yi), can be written as follows (Brebbia, 1978):

C i u i + ∫ q * u dΓ = ∫ u * q dΓ + b i Γ

where:

(1)

Γ

Ci is a constant depending on the location of the point within the domain Ω, ui = u(xi, yi) and

b i = b( x i , y i ) = ∫∫ φ( x, y )u * ( x − x i , y − y i )dxdy Ω

(2)

If the piecewise-discretization concept, which is usually used in finite element analysis, is applied here, then the boundary Γ may be divided into a number ne of sub-boundaries, connected by boundary points, as shown in Figure (1).

28

ANALYSIS OF SOIL MEDIA CONTAINING CAVITIES OR TUNNELS BY THE BOUNDARY ELEMENT METHOD

Γe Y

Γ

. .

.

.

.

. . .

Ω

.

.

.

Nodes

Element

Figure (1) – Boundary discretization.

X

If f (x, y) is a continuous function defined over Γ, then it can be deduced that: ne ⎡ ⎤ f d Γ = f d Γ ⎥ ∑⎢ ∫ ∫ e =1 ⎣ Γ ⎢Γe ⎦⎥

(3)

Applying the boundary-discretization concept, then equation (1) can be rewritten in the following form: ne ⎡ ⎤ ne ⎡ ⎤ Ci u i + ∑ ⎢ ∫ q* (x − x i , y − y i )u(Γe )dΓ⎥ = ∑ ⎢ ∫ u* (x − x i , y − y i )q(Γe )dΓ⎥ + b i e=1⎢ ⎥⎦ e=1⎢⎣Γe ⎥⎦ ⎣Γe

(4)

where u (Γe) and q (Γe) may be approximated by means of interpolation expressions in terms of their values at source boundary nodes. Using such a discretization technique, it is possible to represent a boundary integral equation by means of a simple algebraic equation in terms of the boundary nodal values of field function parameters. Full description of the boundary element formulation is found in El-Zafarany [4], Paris and Canas [5] and Al-Adthami, [1]. All explicit expressions for the fundamental solution parameters given here are found in Al-Adthami, [1]. 2.2 Computer Program A computer program based upon the theory of the two-dimensional solid continuum mechanics problems of the boundary element method with constant elements is coded in FORTRAN 77 and introduced herein. The program can deal with plane stress and plane strain problems with surface and domain loadings. 3. CASE OF TWO CAVITIES Figure (2) shows a schematic representation of the problem to be studied for four values of depth/diameter ratios (Zo/D = 1, 1.5, 2 and ∞). The origin of coordinates (X and Y) is considered at the center of the ground surface.

29


Figures (3) and (4) show the distribution of vertical and horizontal stresses along the centerline of the surface loading (line I-I in Figure 2). The stresses in these figures are normalized by dividing each stress by the initial overburden stress (P). It is obvious from these figures that the vertical stress distribution decreases with the increase of Zo/D ratio and the maximum value of horizontal stress decreases as Zo/D increases. It is also noticed that the values of (σy/P) and (σx/P) become constant at a depth of (Y/D = 5). Therefore, the depth in the figures is restricted to five diameters only. Figures (5) and (6) show the horizontal and vertical stress distributions along a horizontal line 1.0 m below the ground surface (line II-II in Figure 2). These figures indicate that there is a big disturbance in the stress distribution when Zo/D≤ 2 as the cavities approach the ground surface. It is also evident from these curves that the heave effect starts to appear at a distance equals to the tunnel diameter D away from the centerline of the surface loading. Figures (7) and (8) show the distribution of horizontal and vertical stresses along a line 7.0-meter away from the centerline of the load width, (line III-III in Figure 2). It is noticed that disturbance in the stress distribution extends to a depth of about (Y/D = 3). Below this depth, the stress distribution tends to be uniform. Figures (9) and (10) show the contour lines for four values of Depth/Diameter ratios (namely, Zo/D = 1.0, 1.5, 2.0 and ∞). The contours are drawn for vertical displacement and vertical stress distributions, respectively. These figures reveal that the highest values of displacements and stresses concentrate in the space between the cavities. 4. INFLUENCE OF ECCENTRIC LOCATIONS OF CAVITIES Figure (11) shows a schematic representation of the problem to be studied for five values of eccentricity/diameter ratios (e/D = 0, 1, 2, 3 and ∞). Figure (12) shows the vertical displacement (Uy) distribution along the ground surface. It can be noticed from this figure that the effect of the cavity on the surface settlement must be taken into consideration if e/D < 3 and neglected otherwise. This figure also provides designers with some guidance regarding the influence of the cavity location on the settlement of the ground surface. Figure (13) shows the vertical stress distribution over a line 3 meters below the ground surface (line IV - IV in Figure 11). From this figure, it is noticed that when the cavity is about 4.0 m away horizontally from the centerline of the surface loading (e/D = 1), σy on this line increases by about 5% from the case of no-cavity under the center of the surface loading. While for other values of e/D ratio, σy decreases. Also, heave stresses appear on the area above the cavity on this line. Figures (14) and (15) illustrate the variation of σy and σx on the centerline of the surface loading. The effect of the cavity can be neglected in computing the stress values on this line when e/D 3), the surface settlements do not exceed 6 % from those obtained for the case of no-cavity condition. 4. The vertical displacement of the soil medium increases by decreasing the distance between the adjacent openings. 5. In general, small values of K/D ratios (where K is the distance between two cavities and D is the diameter of one cavity) should be avoided to hinder rapid increases in the stress concentration. 6. The region between the two adjacent cavities is more influenced by the distance “K” variation than the outer regions. 0

X (m)

5

10

15

20

0.0000 0.0002 0.0004 0.0008 0.0010 0.0012 0.0014

K/D=0.5 K/D=1.0 K/D=2.0 K/D=3.0 K/D= ∞

0.0016 0.0018 0.0020

Figure (21)-Vertical displacements on the ground surface. X (m) 0

5

10

15

20

0.00000 0.00005 0.00010

Ux (m)

Uy (m)

0.0006

0.00015 0.00020

K/D=0.5 K/D=1.0 K/D=2.0 K/D=3.0 K/D= ∞

0.00025 0.00030 0.00035

Figure (22)- Horizontal displacements on the ground surface.

44


7. REFERENCES: [1] [2] [3] [4] [5]

Al-Adthami, R. A. J., (2003). “Applications of the Boundary Element Method to Soil Media Containing Cavities”, M.Sc. thesis, University of Baghdad. Beer, G., Smith, I. and Duencer, C., (2008). "The Boundary Element Method with Programming", Springer-Verlag Wien New York. Brebbia, C. A., (1978). "The Boundary Element Method for Engineers", Pentech Press, London. El-Zafrany, A., (1992), “Techniques of the Boundary Element Method”, Ellis Horwood, New York. Paris, F. and Canas, J., (1997). (Boundary Element Method-Fundamentals and Applications), Oxford University Press.

APPENDIX I -0.1

0.0

0.1

0.2

0.3

0.4

0.0

0.5

0.0

0.0

0.5

0.5

1.0

1.0

1.5

1.5

2.0

2.0

2.5

2.5

Y/D

Y/D

-0.2

σx/Pσx/P

3.0 3.5 4.0 4.5 5.0

0.2

0.4

σy/P

0.6

0.8

1.0

3.0 3.5

K/D=0.5 K/D=1.0 K/D=2.0 K/D=3.0 K/D= ∞

4.0 4.5 5.0

Figure (23)-Horizontal stress distribution along line I-I.

K/D=0.5 K/D=1.0 K/D=2.0 K/D=3.0 K/D= ∞

Figure (24)-Vertical stress distribution along line I-I.

45


0.7

K/D=0.5 K/D=1.0 K/D=2.0 K/D=3.0 K/D= ∞

0.6 0.5

σy/P

0.4 0.3 0.2 0.1 0.0 0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

X/D

Figure (25)-Vertical stress distribution along line II-II. 0.15 0.10 0.05

σx/P

0.00 -0.05

K/D=0 .5

-0.10

K/D=2 .0

K/D=1 .0 K/D=3 .0

-0.15

K/D= ∞

-0.20 0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

X/D Figure (26)-Horizontal stress distribution along line II-II.

46

4.0

4.5


0.6

K/D=0.5 K/D=1.0 K/D=2.0 K/D=3.0 K/D= ∞

0.5

σy/P

0.4 0.3 0.2 0.1 0.0 0.0

0.5

1.0

1.5

2.0

X/D

2.5

3.0

3.5

4.0

4.5

Figure (27) – Vertical stress distribution along line III-III. 0.20

K /D = 0.5 K /D = 1.0 K /D = 2.0 K /D = 3.0 K /D = ∞

0.15

σx/P

0.10 0.05 0.00 -0.05 -0.10 0.0

1.0

2.0

3.0

4.0

X /D

Figure (28) – Horizontal stress distribution along line III-III. 24 21

Etlevation (m)

18 15 12 9 6 3 0 -24 -22 -20 -18 -16 -14 -12 -10 -8

-6

-4

-2

0

2

4

Distance (m) (a)

47

6

8

10 12 14 16 18 20 22 24


24

Elevation (m)

21 18 15 12 9 6 3 0 -24 -22 -20 -18 -16 -14 -12 -10 -8 -6 -4 -2

0

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21 18 15 12 9 6 3 0 -24 -22 -20 -18 -16 -14 -12 -10 -8 -6 -4 -2

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8 10 12 14 16 18 20 22 24

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0

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10 12 14 16 18 20 22 24

Figure (29)-Variation of vertical displacements in (mm) for: (a) K/D = 0.5, (b) K/D = 1, (c) K/D = 2 and (d) K/D = ∞.

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24 21 18

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15 12 9 6 3 0 -24 -22 -20 -18 -16 -14 -12 -10 -8

-6

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15 12 9 6 3 0 -24 -22 -20 -18 -16 -14 -12 -10 -8

-6

-4

-2

Distance (m) (d) Figure (30)-Variation of vertical stresses in (kN/m2×10) for: (a) K/D = 0.5, (b) K/D = 1, (c) K/D = 2 and (d) K/D = ∞.

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GUIDELINES FOR IMPLEMENTING PIPELINE INTEGRITY TOWARDS MINIMIZATION OF HAZARDOUS ACCIDENTS WITH PRACTICAL AND INDUSTRIAL CASE STUDIES 1

M. El-Gammal (Sr.)1, H. El Naggar2*, M. M. El- Gammal (Jr.)1

Department of Naval Architecture and Marine Engineering, Faculty of Engineering, University of Alexandria, Egypt. 2 Civil Engineering Department, ALHOSN University, P.O. Box: 38722, Abu Dhabi, UAE. ABSTRACT: In a progressive environmentally conscious world gearing towards sustainability, pipeline designers, builders, and operators are faced with an escalating number of complex limitations and restrictions; all focused on increasing safety standards and reducing the risk of any potential pollution. The main objective of the current paper is to propose a new technique for risk estimation aiming at reducing bursting, explosions, fires, and corrosion of pipelines. Also, to demonstrate the new estimated risk concept by introducing analysis of various cases of pipeline accidents. So, the paper serves clearly in pipeline safety measures and pipelines integrity management. It is important to realize the meaning of pipeline integrity by managing safety as well as carrying out risk analysis through implementing the Asset Integrity Management (AIM) concepts. The pipeline problems could be definitely reduced as well as serving without non-expected or non-predicted hazards against loss in property, loss in lives, or loss of the pipeline itself. This paper defines risk as applied to pipeline integrity by estimating the consequences which is being based on root cause analysis. The latter is found to depend on several surrounding and environmental factors. Practical examples from real industrial life problems have been investigated and demonstrated in views that the application of the root cause analysis, RCA, together with a scheme of AIM will reduce the recurrence of those accidents once the real cause has been known and properly maintained. Keywords: pipeline, sustainability, Asset Integrity Management (AIM), Root Cause Analysis (RCA)

1. INTRODUCTION Over the last few decades, the oil and gas industry has witnessed an unprecedented extensive development. Billions of dollars have been spent on construction of pipelines and infrastructure projects. Thus, quantifying the risk of potential problems associated with the operation of these infrastructures is of paramount importance for all stakeholders. Traditionally, academicians used to teach their students only strength governed designs and facts of how to avoid catastrophic pipelines accidents. Nevertheless, in real practice due to the wrong practical treatment of the pipeline or by applying the wrong alternative solution offered and assumed within a design philosophy based on similar problems that may be far different from what safety seniors say [1-3]. Anyway one of the best advises the well experienced seniors in fields of pipelines, whom, used to recommend to their juniors that: “do not play with the pipeline, especially if it were containing flammable materials, such as gas and oil.” But instead juniors must be aware in prompt of how to deal with practical implementations of solutions. This is to be formulated through real gaining of practice as well as the well flow of information granted and collected from expert seniors of some of the vast remarkable theoretical and practical experience [4]. ____________________________________________ * Corresponding Author. Tel.: +971 2 4070529, E-mail : [email protected]

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M. EL-GAMMAL (Sr.), H.EI NAGGAR, M.M. EL-GAMMAL (Jr.)

Recent pipeline accidents [5-10] show that there will be too much work needed to safeguard imminently our pipelines against fire, bursting and explosion hazards that will produce panic and thus the loss of property as well as resulting in the more expensive tragedy the loss of lives. The intent of the present paper is to highlight reasons and causes of pipeline failures due to corrosion hazards. Furthermore to define the Root Cause Analysis “RCA” that must be based in turn on risk. The probabilistic approach that implies the calculations of consequences form contingent plans of safety through implementing the types of maintenance necessary to be carried out right in time. Deploring the monitoring and implying the quality auditing to promote reduction in downtime and to improve pipeline integrity as well as will deploying the lifetime at large will aim to reduce the leak before break and thus will reduce the risk of catastrophic explosion. Definitely there will be no one unique solution to the problem of pipeline integrity and safety hazard prevention. But instead the designer ought to cover as much as he could from information from similar trouble shooting cases and then he could tailor the solution that definitely will reduce the risk. Yet this reliable solution again needs vast experience that some may be lacking. Thus the best solution and the better utilization of handling pipelines integrity problem shall be implemented and tabulated for any project while it is still in the paper stage. Alternative solutions must also be offered ready to be applied without trial and error but mathematically modeled and virtually implemented. The trial and error depends on luck more than engineering matters and technical assessments and thus, it will be waste of time as well as waste of money, waste of efforts and waste of property to apply that concept. So, it would be more reliable to rely on RCA applied in pipeline integrity, if the material, the environment, as well as the operators are all the same or nearly so. 2. DOES THE ASSET INTEGRITY OFFER THE BEST PIPELINE SOLUTION? 2.1 Definition and measures of integrity Definition of the word “Asset” means evaluation, while the word “Integrity“ means unbroken completeness or totality [11]. That means in simple terms that Asset Integrity means the unity of evaluation for the wholeness of completeness. It is considered as the tool for management integrated solution offering the best of the better of choosing from the best design, better choice of materials and the better available manufacturing processes as well as the best assembly sequences and procedures for a pipeline. That is being assumed to be serving within an extreme aggressive environment. Thus it is a toolkit for reducing trouble shooting with better care to develop successful means to better managing the surrounding environment and better control of utilization of all production aspects in pipelines projects. This includes improving in the estimated lifecycle through better inspection intervals of monitoring. Thus this toolkit can give the management an overview leading to efficient evaluation of the project and reducing sudden catastrophic failures, by reducing the accidents in pipelines. Asset Integrity is anything of a value that incorporates owns that is held in firm adherence to a code.

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GUIDELINES FOR IMPLEMENTING PIPELINE INTEGRITY TOWARDS MINIMIZATION OF HAZARDOUS ACCIDENTS

2.2 Benefits and objectives from application of asset pipeline integrity in oil and gas fields: In the oil, gas and power industries mitigating risk to Accidental Probablistic Risk Levels is not only vital to ensure compliance with legal requirements, but also reducing significant everyday losses: • • • • • •

Improving safety alerts and environmental integrity through extending pipeline life cycle, Optimizing maintenance intervals and lower maintenance costs as well as less unplanned downtimes thus improving lifecycle and thus increrase productivity Reducing ligament thickness - metal loss due to corrosion deterioration and degradation problems, Machining slits (parent metal, seam weld, heat affected zone) defects can all be monitored and eliminated, Reducing the probability of fatigue cracks thus can control the sudden hazard events, Identify and reduce hazards due to dents,dent/slit combination and mechanical damage will also be under control.

2.3 How and why do Asset integrity being manipulated within the process of safety standards? Asset Integrity is committed to prevent incidents that put people, neighbors, the environment and the facilities at risk. Therefore, asset integrity is the safety process which gives the decision maker the assurance that the facilities are well designed, safely operated and properly maintained, [12]. What is meant by Asset Integrity Approach and how it could be more useful in pipeline applications? Asset Integrity approach in pipelines integrity practical problems has been proposed from two or more decades [13-15] and denoted in Figures 1-a and 1-b. Figure 1a gives the triangle of management decision success applied within asset integrity in fields of pipeline projects. It is based on root cause analysis which method can be applied to prevent the recurrence of the bad event in pipeline once again. Figure 1-b explains how the flow of information in the building up of correct decision is based on asset integrity, while Figures 1-c gives the different uses and the main pipeline applications now in current use. From that figure one can note the importance of maintaining pipelines. The figure as seen describes at its top the different types of pipelines currently applied. At the middle it demonstrates the different uses of pipelines in our wells, within different refineries’ departments, then to transportation facilities and ships to transfer oil, gas and their products using ships. The store tanks at the end of the transportation must be fitted also with pipes of different sizes, varieties in materials. All are to be serviced as terminal tanks for the end process of transportation. Then the feeding pipes to the industrial facilities are to be monitored to prevent environmental safety hazards. The last in the important cycle of pipelines harmony are those used to feed domestic uses in houses for warming, cooking and all other very important uses in the house hold equipment. The lower portion of Figure 1-c shows the different categories of pipelines in various

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engineering fields of practice. Those figures are aimed at demonstrating the importance of risk based criteria.

Fig. 1-a: Asset integrity applied with RCA will lead to better utilization of pipeline [13-15]

Fig. 1-b: Pyramid of asset integrity the top is Asset Integrity at the base Safety of public interests and in between the inspection which means close supervision and proper maintenance of a pipeline project.

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Fig. 1-c: Practical and industrial uses of pipelines [16-19]

Figure 2 [23 & 24] shows the four steps for Risk Cost Identification and Assessment. From that figure that the first step in any model of pipeline risk assessment is being divided into several stages. The first stage is how to identify the cause and to recognize the hazard reason. The second stage is how to develop the risk assessment of that hazard if it were happened. The third stage in the model is how to devise a proper solution to control the hazard and its consequences. The fourth step is how to be able to estimate the cost of benefit associated with the involved savings of lives and properties against the determined risk. The fifth and final stage is how to demonstrate and to recommend a tailored decision for the management to take. Of course all steps are to be based on monitoring times, intervals and capabilities of the inspectors.

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Generally the basic decision making is liable to bench marking and thus the success can be assessed by the use of KPI “Key Performance Indicator”. In case if there is alternative different solutions to deal with the same hazard then the KPI must be assessed for each alternative and by then the right measured value can give guidance to the management to decide which is the best alternative to be followed and thus which is being recommended.

Figure 2: Steps followed in Risk Identification [23]

3. RISK ANALYSIS IN PIPELINE INTEGRITY Risk assessment provides a structured basis for pipeline operators to identify hazards and to ensure risks being ultimately reduced to appropriate levels in a cost-effective manner. The regulations applying to offshore operations in the pipelines’ industry require operators to undertake risk assessment in order to identify appropriate measures, as far as is reasonably practicable, to protect people against accidents. It may well be that the use of Quantitative Risk Assessment (QRA) for Temporary Refuges has given the impression that risk assessment is synonymous with QRA [22-24]. A risk assessment and management process that is focused on loss of containment of pressurized equipment in processing facilities, due to material deterioration is called by Risk Based Analysis [22]. These risks are managed primarily through equipment inspection. Root Cause Analysis ‘RCA” has two important roles in pipeline integrity management: 1. Identify Operational problem and issues 2. Identify consequences of a failure 2.1. Includes criticality –if equipment goes down, what are the effects on the system 2.2. Share consequences of past failures

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1

Likely

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Rare

Decreasing Likelihood

Figure 3-a [22], shows the 6x6 ISO Risk Matrixes. As seen in this figure the likelihood of a bad event goes down starting at one for the lowest and goes to six at the utmost for the rare event. The six categories of probabilities of the event are two for the occasional, three for seldom, four for unlikely and five for remote. The impact and the consequences of the same event are defined by one for Catastrophic event, two for the severe, three for the minor, four the minor, five for the moderate and finally six for the incidental. Each will be having different values of weight factors as seen in the matrix. The weight starts with a value of unity for the likelihood and the catastrophic consequences and goes up to the value of 10 for the rare event and the incidental consequences. The ISO matrix as such is composed of 6 events x 6 impacts. Nevertheless, the ISO matrix can be reduced to be 5x5 matrix as shown in Figure 3-b.

Consequence Indices

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1

Severe Catastrophic


4. STANDARD QUANTITAIVE RISK ASSET (SQRA) As has been explained earlier that the calculated risk should be compared with a constraint value, named here by “Standard Quantitative Risk (SQR)”, to know whether the event is an expected, tolerated, predicted or a non-predicted one. Most of the Regulatory Bodies and Classification Societies have put forward risk motivation studies. In doing so, they have suggested constraint values quoted here as standard risk values. Yet those standard values can generally be applied to any of the pipeline integrity problems. 5. SUGGESTED TECHNIQUE FOR RISK ANALYSIS APPLIED WITHIN PIPELINES The purpose of this work is to furnish a guidance of proposing a risk assessment method for pipelines through applying simpler techniques and methods leading to better end of risk assessment. The qualitative and semi-quantitative techniques have been applied to define standard risk values in accordance to the concerned Classification Society. It explains risk assessment technology as it might apply to pipeline operations, emphasizing techniques appropriate to pipeline hazards. Quality Risk Assessment “QRA” has a role in some pipeline applications, since it demonstrates how the wider range of techniques can help operators perform a suitable and sufficient risk assessment, and demonstrate that risks are As Low as Reasonably Practicable (ALARP) [22]. Figure 4 gives the flow diagram leading to the assessment of the integrated hazard in pipeline safety management.

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Figure 4: Assessment of Integrated Hazard Identification in Pipeline Safety Decisions

The prediction criteria is such that if the estimated risk exceeds the standard value then the accident shall be considered as to be expected, but if the estimated value is less, the accident is said to be non-expected but happened. Equation (1) is based on the two risk dividends. The first is known to be the frequency or the probability of the event. The second is known as the consequences and impacts from that event. Figure 5 highlights the sequence to be followed in the calculations of risk as shown by equation (1).

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Risk = PE * TC

(1)

Where, PE is the frequency probability of the event E, TC is the summation of consequences of the resulted impacts of that event as denoted by eq. (2). The total impact of the consequences of an event is thus that denoted by equation (2) and Table I. TC = LV + LP + S + E + Q + T + O + I

(2)

where, LV presents the panic due to the loss of lives, LP presents the panic due to the loss of properties, S presents the panic due to the Safety, E presents the panic resulted in the Environment, Q presents the panic in the Quality, T presents the panic due to the Throughput, O

presents the panic due to loss of Operation,

I presents is the catastrophic panic of Immobilization, The corresponding assumed weight “W” for which the probability Pw may follow equation (3). Pw=1/1010-w

(3)

where, w is a weight factor denoting the severity of the event as related to the frequency and the consequences. If the accident is categorized as predicted then measures for reducing the impacts and to prevent the occurrence of that accident must be implemented. That is as indicated by equation (4). REST

>

RCAL

(4)

where, REST is the estimated total frequencies of an event multiplied by the severity of consequences, and RCAL is the tabulated standard value at the corresponding associated Risk,

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calculated as shown in table II to be equal on average to 5. This value has been explained in the next part and Table II and summarized in Figure 5. But if the accident is unpredicted to be non-expected, i.e., remote event, thus equation (5) shall be applied in this case. REST