logistics

GIRNE AMERICAN UNIVERSITY / FACULTY OF ARCHITECTURE DESIGN AND FINE ARTS / DEPARTMENT OF ARCHITECTURE FALL 2015

CMGT 501 CONSTRUCTION PROJECT MANAGEMENT

LOGISTICS Lecturer: Asst. Prof. Dr. Duško Kuzović dipl.eng.arch. Based on: Richard Lambeck, Eschemuller John (2009) Urban Construction Project Management, New York: McGraw-Hill, Yellamraju Vijaya (2011) Leed–New Construction Project Management, New York: McGrow-Hill, Group of Authors (2014) Code of Practice for Project Management for Construction and Development, New Jersey: John Wiley & Sons, Inc.

CRANES Type of crane depending upon the height of the building constructed. For heights of up to 60 meters, a mobile crane can be utilized. Once this height is exceeded, then a climber tower crane will have to be considered. Large projects might have multiple cranes operating simultaneously. For a crane sitting on a city street, the load bearing capacity below its base will have to be analyzed by a structural engineer. The effects of the crane on underground utility vaults, transportation systems, and foundations in the area will have to be considered. Factors might include: 1. Project schedule and attendant requirements for crane picks 2. Available area for picks from the street and movement within the site 3. Cost of crane and operator versus productivity gain 4. Potential interference between cranes in operation or with other equipment operating on the site 5. Need for the hook to reach where needed with requisite lift capacity 6. Needs of trades to work independently of other trades with respect to lift scheduling 7. Potential interference between space requirements for cranes taken out of service and poised for storm winds 8. Potential benefit of having one crane erect or dismantle another crane 9. Load bearing of the ground to support the crane and its lifting load

CRANE SAFETY Accidents in cities receive prominent news coverage that has prompted state legislatures to consider strengthening their regulations. New York City and California have the most stringent crane requirements: 1. Only approved crane models are permitted to be used. Each crane must be registered and inspected annually. 2. Crane operators and riggers are licensed. Tower crane erection dismantling and climbing requires a licensed rigger. 3. Crane installation on new buildings must be engineered and the engineering is then reviewed by the building department. 4. Crane installations must be inspected by either a professional engineer or a building department inspector. 5. All “jumping” of cranes must be observed by a building department inspector and/or a licensed master rigger and independent crane consultant.

A contractor has many incentives to keep safety of the cranes a primary objective and to heed these standards: 1. Problems with the crane can seriously affect the schedule. 2. The governing authorities can mandate heavy fines. 3. Insurance companies will increase premiums. 4. Bond sureties will increase bonding premiums or may decide not to bond the contractor. 5. Reputation can be tarnished. 6. The authorities may impose additional oversight. 7. The CM/GC could have a problem in obtaining “good” bids by subcontractors on future work. 8. With any injury or death, productivity of the workers on the job site decreases.

HOISTS A construction hoist is a temporary elevator that transports workers and material to the various floors in a building. A hoist car that transports people is classified as an elevator and must conform to a more stringent set of standards then a mere material hoist. The hoist cars typically ride on rails that are tied to the structure every two to three floors. One or two cars ride on one mast. On a dual hoist, one car can be for workers and the other car can be for workers or material.

Other safety considerations that must be observed include the following: 1. A 30-foot safety area should be maintained around the cars. This will include the installation of safety nets and a sidewalk bridge. 2. A loading dock shed should be constructed that will protect workers and trucks that will be unloading material at the loading dock. The hoist location within the plan of the structure is determined by several factors: 1. Good access off the street for the unloading of material from trucks. 2. Close to the center of where material will be used on a floor with clear passage that will not interfere with critical finishes. 3. Close to the fire standpipe so that firefighters have ready access when they step off the hoist. 4. Minimal interference with the progress of construction by delaying closing or finishing critical parts of the building. 5. Avoiding potential conflicts with other activities such as crane picks. 6. Access to remove the hoist from the site after the work is completed.

The number of hoists on a project is determined by a cost benefit analysis considering the following: 1. Number of workers that need to go up and down the building at peak times. 2. The amount of material that will have to be transported during the progress of the job. 3. The cost of renting the hoist and the cost of the operators. 4. Availability of temporary power. 5. The cost benefit of schedule acceleration brought about by more carrying capacity versus the possible delaying effect of leave outs at the hoist locations. 6. A rule of thumb is one hoist car for every 250,000 square feet.

CHECK FOR HOISTS 1. Construction personnel hoists 2. Construction material hoists 3. Combination personnel/material hoists 4. Location of hoist—internal or external to building 5. Loading dock for hoists 6. Barricades for hoists and loading dock 7. Signage 8. Flashing yellow caution lights 9. Concrete foundation pad for hoist 10. Tie backs of hoist to the structure 11. Runaways from hoist tower to building 12. Power for hoists 13. Power for lighting and outlets at hoist landings and loading dock 14. Permits 15. Engineering

16. Sidewalk closing 17. Lane closing 18. Direction of the flow of traffic 19. Bus lanes and stops 20. Subway entrances and exits 21. Access to fire hydrants 22. Visibility of traffic signage or relocation of same 23. Zone of influence of the hoist for sidewalk bridge 24. Sidewalk Bridge for pedestrian protection 25. Lighting under sidewalk bridge 26. Anchorage of sidewalk bridge 27. Weather-resistant enclosure at hoist entrance to building 28. Ramps from hoist entrance into building 29. Coordination of hoist location with permanent building facilities 30. Schedule for the availability of permanent service and passenger elevators 31. Use of hoists for construction of tenant fit up program 32. Structural support for the hoist pad, hoist tiebacks, sidewalk bridge, and sheds 33. Structural reinforcing for the hoist area loading dock

TEMPORARY SERVICES AND FACILITIES In order for a construction site to function properly, it must have access to water, electricity, and a sewer connection. An application to the appropriate utility along with an electric load letter is often required by the CM/GCs and owner to arrange for the temporary and/or permanent services required for the project. It often takes quite some time to arrange for services from the utilities depending on whether the service is readily available in the area, the work backlog of the utility, the moratorium period during the holidays, and emergencies that the utilities may be facing. The orders must be placed as soon as the requirements are known. The following is a list of the utilities that should be contacted: 1. Electric utility company 2. Local gas company 3. Local steam provider (if available) 4. Department of water supply 5. Department of sewers 6. Local cable company 7. Local telephone company

TEMPORARY SERVICES CHECKLIST 1. Power for demolition and abatement 2. Power for excavation and foundation 3. Power for hoists 4. Power for loading dock 5. Power for hoist tower lights and outlets 6. Power for sidewalk bridge and sheds 7. Power for field office and shanties 8. Temporary light and power for construction 9. Power for specialty equipment 10. Power for elevators 11. Availability of permanent power a) Saws b) Welding equipment c) Rigging equipment d) Derricks e) Project signage f) Mixing equipment g) Temporary water and pump

12. Temporary toilets/ portosans 13. Temporary water for construction 14. Water barrels for water use and drainage 15. Standpipe for fire protection 16. Siamese connection to feed standpipe 17. Temporary roof 18. Maintenance of temporary systems 19. Utilizing permanent systems for use during construction 20. Temporary heat 21. Interim cooling and dehumidification 22. Interim use of service elevators 23. Interim use of passenger elevators 24. Interim use of building loading dock 25. Protection of facilities 26. OSHA protection, signage, and logs 27. Work that may affect the Transit Authority and zone of influence 28. Maintenance of temporary facilities and standby operating personnel 29. Maintenance of permanent facilities and systems used during the construction process, and the refurbishment of the equipment and extension of all guarantees and warranties

TEMPORARY ELECTRICAL POWER Temporary electrical power needs to be provided and distributed throughout the construction site. Temporary construction power is required for: 1. Temporary light and power stringers that are usually run on a grid of one light and outlet every 120 m1 2. Personnel and material hoists STANDPIPE A temporary fire standpipe needs to be installed in the building during the construction process to allow the fire department to fight a fire if required. One of the permanent standpipes is often used on an interim basis to provide this protection. The standpipe is dry, and fed from a Siamese connection that must be accessible from the street, outside of the sidewalk fence enclosing and securing the site. The height of the standpipe should be not less than two floors below the top floor. A sign must also be provided indicating the location of the Siamese connection at street level

FIELD OFFICES As part of the site logistics planning, it is important to identify the location for the CM/GC field office, and those of the subcontractors. Initially during the demolition and then the excavation and foundation phase of the project, construction field offices are often housed in self-contained trailers that can be rented. The trailers can be located on the site, if open space is available. Often they are located adjacent to the site or on top of the sidewalk bridge surrounding the construction site. 1. CM’s field office 2. Subcontractor’s field office and shanties 3. Subcontractor storage of materials 4. Fire resistant construction 5. Sprinkler protection of shanty areas 6. Emergency evacuation of construction personnel 7. Power for field offices and shanties 8. Location of temporary bathrooms 9. Heaters and A/C for construction shanties 10. Required shanties for Local 14, Teamster, and Master Mechanic

11. Telephone, fax, Internet service for CM and trades 12. Security of site and offices 13. Storage of flammable and hazardous materials 14. Location of office and shanties relative to site entrance 15. Guard booth to control site access 16. Fire extinguishers 17. Types of interim heaters, air conditioners and fire protection 18. Emergency contact information 19. Communication system on the site

STORAGE At most urban construction sites there is very limited space for storage of material, equipment, debris containers, and cylinders. Thus, creative means must be found for finding adequate storage areas for critical elements of the project. This may require the leasing of off-site storage areas, finding areas under stairs for temporary storage, or using off-hour areas such as loading docks for the temporary storage of debris containers. On-Site General Storage Construction in the urban environment presents unique challenges for storage of materials at the construction site. Given the small size of the property, there is not much space surrounding the building on the site to allow for adequate storage. During the construction process, large quantities of construction materials will be delivered to the site for installation in the project. Dumpsters Another challenge of construction in the urban environment is the storage of dumpsters at the construction site, given the limited amount of available space at the ground level. In the logistical planning of the project, the CM/GC will determine if a large dumpster can be accommodated on the site for the storage and removal of debris, or if mini trash containers, with a capacity of less than one cubic yard, will be utilized. Often mini trash containers are used given that they can be wheeled around the building to various floors to pick up debris, and then brought to the hoist or elevator loading dock area for a trash

REQUIRED PERMITS Prior to the start of the construction process, it is important that the CM/GC identify with the local building department, fire department, expeditor, and transportation department those filings and permits that are required to support the required logistics of the construction project, aside from the construction process and permits to perform the work itself: 1. Hoist 2. Sidewalk bridge and shed 3. Scaffolding 4. Fence 5. Crane 6. Derrick 7. Water supply and services 8. Gas supply and services 9. Steam supply and services 10. Electrical supply and services 11. Storm sewer connections 12. Sanitary sewer connections 13. Overtime work permits

Additional filings and permits that are sometimes required from the local transportation department may include: 1. Lane closing 2. Sidewalk closing 3. Pedestrian crossing relocation and/or closing 4. Bus stop relocation 5. Closing of the local transportation system entrances 6. Removal and/or relocation of parking meters 7. Removal and/or relocation of fire hydrants 8. Removal and/or relocation of traffic signage 9. Removal and/or relocation of traffic signals Filings and permits that are sometimes required from the local fire department are: 1. Storage of flammable materials 2. Storage of metal cylinders containing flammable gases 3. Permit to burn fuels 4. Permit to store fuels

MORATORIUMS Some of the major cities in which the CM/GC will be working have a moratorium period for things such as major parades or visits by foreign and domestic dignitaries. During the moratorium period, the local government might not issue a permit for new work or logistics that would potentially disrupt the flow of pedestrian and vehicular traffic.

SIGNAGE In order for the site to comply with traffic, safety, and notifications regulations, numerous signs must be installed in and around the site. Proposed construction site signs: 1. Contractor’s name • Address • Emergency telephone number 2. Building Department • To contact in case of an emergency with telephone number • To contact in case anyone notices a violation 3. Demolition subcontractor • Name and emergency telephone number is listed 4. Excavation subcontractor • Name and emergency telephone number is listed

5. Directional sign for pedestrians • No Entry • Sidewalk closed • Follow the sign for the temporary walkway 6. Security signs • Authorized personal with proper badges • Gate locations • Personal gate locations 7. Height signs • At loading dock for truck information 8. Hydrant sign • For fire department identification

9. Street closing • Lane closing as per DOT permits • Street closing as per DOT permits 10. No smoking signs • Hang around the site so that workers refrain from smoking 11. Hard hat work area • Everyone on the site must wear a hard hat 12. Eye protection • Workers who are cutting, sawing, or burning material should all wear eye protection 13. General safety signs • Remind all workers that safety is a primary concern 14. No parking sign • Authorized parking only • Parking required for trucks, pumpers, concrete, steel delivery. 15. Flag personal • On occasion, a flag person is required to: (1) divert traffic, (2) hold pedestrian traffic while picks are occurring, and (3) when buckets are being raised or lowered 16. Transportation signs • Bus stop location • Underground transportation location • Tram location

SECURITY: SIDEWALK BRIDGES, SHEDS, AND FENCING Security of the total site is of extreme importance to the owner and workers. The owner does not want unauthorized personnel walking around the site. This could create a liability problem if someone is injured on the site and is not authorized to be there in the first place. In addition, expensive tools, equipment, and components have to be protected from theft. Sidewalk bridge/ sheds checklist: 1. Construction personnel hoists 2. Construction material hoists 3. Combination personnel/material hoists 4. Loading dock for hoists 5. Barricades for hoists and loading dock 6. Signage 7. Flashing yellow caution lights 8. Concrete foundation pad for hoist

9. Tie backs of hoist to the structure 10. Runaways from hoist tower to building 11. Power for hoists 12. Power for lighting and outlets at hoist landings and loading dock 13. Permits 14. Engineering 15. Sidewalk closing 16. Lane closing 17. Direction of the flow of traffic 18. Bus lanes and stops 19. Subway entrances and exits 20. Access to fire hydrants 21. Visibility of traffic signage or relocation of it

UNDERPINNING AND SHORING CM/GC must analyze the conditions that exist and make sure that the older surrounding buildings will remain stable during the excavation of the new building. This may require the temporary support of the older buildings’ footings or the placement of a wall around the new site that will support any load emanating from the older buildings’ footings. Methods for Securing the soil (excerpts): Jet grouting Freezing of the soil Minipiles Straddling footings with needle beams Soldier beams and lagging Steel sheeting Slurry wall Soil mixing

UNDERPINNING AND SHORING CHECKLIST 1. Obtain drawings of the existing building’s foundation plan. 2. If required, dig small test pits around the foundation without disturbing the structure. 3. Prepare a plan of the new excavation and foundation in relationship to the existing building’s foundation. 4. Show a section at the elevation of the new foundations in relation to the old foundation and the distance between the two. 5. Indicate the type of existing foundation (spread footing, piles, mat, etc.). 6. Indicate the material of the existing foundation (stone, concrete, steel). 7. Indicate type of soil or rock encountered under the old foundation. 8. Determine estimated load on the existing foundation. 9. Locate any water and determine the elevation. 10. Review all information with the soils engineer and underpinning specialty contractor.

Jet grouting A series of pipes are run in the ground under the footings of the existing buildings. Grout under high velocity is then sent through the pipes. The grout breaks up the soil structure and creates a solid grout–soil mass under the footings.

Freezing of the soil A closed pipe system surrounds the footings and refrigerant then runs through the pipes. The soil then becomes frozen under the existing footings and the new excavation work could continue. In addition, this may be a temporary method until a more permanent underpinning method is employed as will be described further. This method can also be used to temporarily stop water flow that may be affecting the site construction.

Minipiles Small diameter (4 to 10 in.) piles are driven through the foundation of the existing building (and the new building’s partly excavated area). These piles can be made of steel, steel pipe (filled with concrete), or concrete. If vibration is a problem, then pre-bored concrete or pipe piles would be placed in the ground and then grouted in place. The minipiles could be used as end bearing or friction piles (if sufficient pile surface area can develop the required frictional stresses).

Straddling footings with needle beams New footings can be installed on either side of the existing footings. Then steel beams (called needle beams) would be pushed through the soil to be supported by the new footings. The needle beams would then support the old footing.

Soldier beams and lagging Steel H piles are driven into the soil to a depth below the excavation level. As the earth is removed for excavation, wooden slots (lagging) are placed between the H piles. Depending on the stability of the soil, it may also be necessary to anchor the H piles. This is accomplished by placing rods (orcables) into the soil or rock behind the H piles and lagging and then anchoring them in place by grouting the rods or cables. If the soil is not capable of taking the load of the anchors, then rackers are placed to brace the soldier beams and lagging from inside the excavation.

Steel sheeting Four feet length (or longer) of steel sheeting is “piled” into place to the depth of the excavation. The sheeting sections are attached to one another by interlocking with the next section. As the earth is excavated, the sheeting is anchored back to the soil or rock as described in the previous paragraph.

Slurry wall A clam bucket excavates a trench around the site. As soon as the trench reaches a depth where the earthen walls are no longer stable (and will collapse) a slurry mixture (bentonite) is placed in the trench to stabilize the walls. Once the trench and slurry reaches a depth below the excavation elevation, then a reinforcing steel cage is placed in the trench. Once this process is completed, concrete is poured into the trench, replacing the slurry mixture (which is reused). Once the concrete hardens, the concrete wall is then anchored to the soil or rock as stated previously. In some cases, precast prestressed concrete panels are used in lieu of pouring the concrete (with the reinforcing steel cage).

Soil mixing This procedure mixes grout with the soil (by rotating paddles) to create small long cylinders (that reach the bottom of the excavation). The continuous linking of these cylinders would provide a wall around the site.

EXCAVATION Excavation is a method for removing earth and rock from a site in order to get to a certain elevation, usually below street level. The reasons for getting to a lower elevation could be for: 1. Basement storage area 2. Mechanical equipment room 3. Electrical rooms, especially for entering electric service that would emanate from a transformer that is installed below the street level 4. Utilities coming into the site from those that are buried in the street 5. Spread footings for the foundation 6. Parking garage 7. Special functions for the building (meeting rooms, gym, etc.)

INITIAL EXCAVATION LAYOUT The site engineer indicates on the site plan the boundary of the area to be excavated. The subcontractor responsible for the excavation checks the layout that was initially created by the CM/GC’s surveyor. Once the layout is confirmed, a fence is established around the site (with access gates for equipment), so the public is protected from the excavation. In addition, the CM/GC is protecting the site for security reasons and for possible intrusion from unauthorized personnel. The CM/GC has to be concerned about injury to unauthorized people who may enter the excavation for whatever reason (vandalism, burglary, or just for fun).

THE EXCAVATION EQUIPMENT Heavy equipment is brought in to start the removal work. This can consist of bulldozers, rock crushers, trucks, backhoes, compressors, tunnel drills (for any required tiebacks), or even a crane with a scope bucket attached. Trucks will need access to the site for removal of the dirt. In order to protect the public, when equipment enters or leaves the site a flag person is stationed at the access gates stopping pedestrians from crossing in front of the equipment that may be arriving or leaving the site. When the excavation is completed, the equipment is removed from the bottom of the excavation by the use of a crane.

EXCAVATION STABILITY When the excavation reaches a certain elevation below the initial grade level and the point at which the sides of the excavation may become unstable, then some retaining system is required. The side of the excavation may become unstable because the soil cannot maintain a 90° cut or the pressure being exerted by the soil from street traffic loads or other conditions becomes too great. When this condition exists then the methods outlined in the section on sheeting will have to be implemented. If an existing building is close to the excavation, then shoring and underpinning may be required.

ROCK EXCAVATION At one time, rock was removed by blasting with dynamite. In order to protect the public, metal mats were placed so that the rock pieces would not fly into the air and injure someone. Now, in most urban situations, blasting is not allowed due to the potential dangers, dust, vibration, and noise. Rock crushing and drilling machines are now used to break up the rock.

Rock crusher

DEWATERING

Dewatering is the process of removing water from the construction site so: to keep surface water away, and pumps to drain the subsurface of the site and lower the water table That the work can be performed in a dry site DEWATERING Dewatering is the process of removing water from the construction site so: to keep surface water away, and pumps to drain the subsurface of the site and lower the water table That the work can be performed in a dry site

Well Point Dewatering

SUMMARY A good logistics plan is one of the key ingredients for a successful urban project. Protection of the public by fences, bridges, and other barriers is a paramount consideration for an urban construction project. In order to be efficient and to meet critical schedules, the movement of trades people and material must be analyzed. Thus, the location and number of hoists and cranes must be determined by the CM/GC and related subcontractors. Signs must be placed around the site for directing the public around the site, notification in case of emergency, traffic flow, and safety considerations on the site. In urban settings, storage of material, cylinders, and dumpsters is extremely difficult due to the limited amount of space at the site. Therefore, off-site storage must be considered and space must be set aside on site for dumpster and cylinder storage. Urban sites require the evaluation of structures adjacent to the proposed site. Underpinning of the adjacent structures may be required for stability. Several methods could be used, such as minipiles, shoring, and needling. When excavation takes place, the side walls have to be stabilized. This could entail soldier beams, sheeting, or slurry walls. Since urban centers are located near major waterways, the groundwater table may be close to where the site will be excavated. Thus, several methods are used to remove the water from the site, such as sump pumps and well points.

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