SAFETY MANAGEMENT
8.2 BUILDING INFORMATION MODELING (BIM) 1
8.2.1 Capture Pre-existing Site Conditions
Typically, a preliminary pre-construction property third-party survey is highly recommended to docu- ment existing conditions of adjacent structures and surrounding areas prior to commencement of con- struction . The survey is performed mostly to protect against third party liability exposures . Three-di- mensional laser scanning can be used to capture the baseline existing model . BIM with information obtained using 3D laser scanning can capture pre-existing conditions accurately that can be built into the model .
8.2.2 Constructability Reviews
BIM can be used to conduct constructability reviews due to its ability to visualize what is being con- structed in a simulated environment . It helps identify potential errors and omissions and reduces change orders, which improves the quality and can prevent rework . Less rework means better safety performance and higher efficiency .
8.2.3 BIM Enabled Prefabrication
A fully coordinated BIM model can isolate, analyze, and construct any area of the building with a higher reliability . Hence, BIM enables more items to be prefabricated off-site (e .g ., pipe assembly), transported to the site, and installed rapidly . Prefabrication minimizes field work and on-site labor and construction, which reduces worker exposure to unsafe conditions (e .g ., working at heights, working in inclement weather, etc .) . Less exposure means better safety performance . For example, in one project several heating/cooling pipes were assembled off-site in a controlled environment, trucked to the site, and installed quickly and safely . It helped alleviate issues with access, fall protection, and ergonomic concerns .
8.2.4 Designing for Construction Worker Safety (DfCS)
DfCS requires one to consider construction site safety during project design . BIM provides an excel- lent visualization of the project design; hence construction safety professionals can use BIM to iden- tify where DfCS suggestions can be incorporated . For example, in one project, fall protection anchor points were determined using BIM . BIM review revealed many areas where workers would be exposed to fall hazards, but no anchor points were present . The project team identified several hundred loca- tions where concrete embedded straps could be installed for anchors . BIM helped identify potential conflicts with overhead or under-slab utilities . Chapter 7 of this handbook has a checklist that identi- fies, by discipline, some safety specifics that can be considered using a BIM .
8.2.5 Construction Site Logistics and Emergency Planning
BIM enables contractors to study existing and future site conditions and hazards before breaking ground, such as traffic considerations, site access, utility concerns, crane radius, and lay down areas . For example, BIM can be used to simulate crane operations in relation to the overhead power lines . It can enable communication with neighbors and subcontractors (see Figure 8-1) . For example, in one project BIM was used to map on-site equipment flow . The project required extensive use of dump trucks to transport materials from the excavation pits . A gravel ramp was the best solution for the trucks to enter and exit the excavation area . Locating the ramp correctly, in relation to other construc- tion activities, is critical to proper truck access and avoids congestion and trade stacking . BIM helped
Figure 8-1: BIM-enabled Site Logistics and Emergency Planning (Photo courtesy of BNBuilders) 8.2.6 Safety Training and New Employee Orientation
Craftspeople new to the jobsite are at a higher risk of injuries until they understand the site’s work- ing environment . BIM can help them more fully and quickly understand the environment . Figure 8-2 shows the site layout derived from BIM identifying emergency access, safety bulletin board, site office, fire extinguishers location, etc .
Figure 8-2: Site Safety Plan Integrated with BIM (Photo courtesy of BNBuilders)
8.2.7 Site Specific Safety Plan (SSSP)
The SSSP can be integrated into the BIM model to identify and control a project’s potential hazards . For example, risks posed by site utilities and their proximity to the overhead power line can be ana- lyzed and controlled adequately prior to commencement of work . BIM would be perfect to develop emergency access and evacuation route plans .
8.2.8 Job Hazard Analysis (JHA) & Pre-task Planning (PTP)
Pre-task planning offers the most opportunities to use BIM for construction safety . By virtually look- ing at the elements to be built, employees can better identify the hazards and control measures so the task could be completed faster and more safely (see Figure 8-3) . BIM can be used to evaluate construc- tion sequencing of high-hazard tasks such as steel erection, construction hoists installation, and tower crane erection . The evaluation can eliminate a variety of conflicts with other work in that area before activities commence .
Figure 8-3: Pre-task Planning & BIM: Model vs. Actual As-Built (Photo courtesy of BNBuilders) 8.2.9 Utility Access
BIM allows better understanding of service access to above ceiling devices such as terminal units, fan coils, and electrical junction boxes . If these areas have limited access, they can pose a safety issue to start up, service and maintain .
8.2.10 Accident Investigation
BIM can be used during an accident or incident investigation to recreate event sequence and the inci- dent scene . In one case, a worker was injured when he fell off a leading edge . The project had not used BIM, but during the incident investigation, laser scanning was used to identify existing conditions at the scene, such as location of pipes and HVAC ducts; location of stored equipment; materials storage;
and worker position . With these data, an existing condition BIM was created, which captured the in- cident scene . This model eliminated hundreds of pictures and answered numerous questions related to the scene . It seems logical that BIM can be used during legal proceedings to save resources .
BIM has the potential to improve construction project safety performance . Safety professionals in the construction industry should view building information modeling (BIM) as a tool to improve worker safety and health . BIM can be used in worker safety training and education, design for safe- ty, safety planning (job hazard analysis and pre-task planning), accident investigation, and facility
to review safety issues while performing design or constructability reviews . BIM is a tool that can facilitate this process .