High rise buildings are all around us. Not just located in large cities, they’re abundant across most urban landscapes. You might wonder what exactly constitutes a high-rise building? Well, that depends on where you are in the world. In some parts of Europe, it is defined as at least 105 feet tall. India defines it as 45 feet or greater in height. Here in the U.S., the National Fire Protection Associate defines a high-rise as a building higher than 75 feet. The five-story Vast Bank building Ross Group recently constructed across from ONEOK field exceeds that height, measuring at 124 feet.
Unless you happen to see one under construction, you probably don’t think about the numerous safety issues and planning that goes into providing a safe building design, as well as the safety requirements during construction. To learn about typical safety requirements for this type of building, we caught up with Caleb Lundry, assistant project manager on the Vast Bank facility, to discuss the safety aspects his team had to consider during construction of the building, as well as some of the features incorporated into the design of a building to keep the tenants safe once they occupied the building.
What are some of the safety protocols you had to consider during construction?
Although the construction industry strives to keep both workers and the general public safe throughout any construction project, working on a high-rise facility presents a different set of challenges. With any construction project, falls are the leading cause of injuries and deaths on the job site. Through planning and coordination, Ross Group took a proactive approach to identifying potential fall hazards to protect employees. This was accomplished by either removing the fall hazards by installing guard rails or protecting the employees through training and fall protection equipment. Ross Group also took the additional step of inviting 3M, a manufacturer of fall protection equipment, to the job site. 3M demonstrated the proper methods of using fall protection equipment to our staff and subcontractors. The entire team was very cognizant of this critical safety issue and took every precaution to avoid an accident.
A specific scope of work that required fall protection was the work on the two elevator banks/stair towers in the center of the structure, which extend the full height of the building. These elevator/stair cores were cast in place concrete structures. The formwork we used served as an elevated platform with attachable guardrail systems so that, while working on the elevated forms, employees were protected from fall hazards. Once one elevation was placed, the forms would be crawl up to the next elevation to be placed, and workers would secure the forms to the concrete that had been placed below. During construction, the team used a manlift to provide worker access to the towers and higher-level elevations of the rest of the building.
Another safety hazard was the small size of the project site, which is often the case with high-rise facilities since they are common to downtown areas or other highly populated areas. This provided numerous challenges that required us to thoroughly plan to keep workers safe due to the close quarters of materials and equipment. For instance, the scaffolding around the building was almost up against our job site fence, so the team was careful to keep tools and materials from falling off scaffolding. Another thing we took into consideration was shipping and receiving loads in and out of the site. This was more difficult than you would expect due to the project being in the downtown area. Ross Group developed and maintained a strict delivery schedule so material entering and leaving the jobsite could easily flow. When large deliveries were scheduled, occasionally streets would be closed so not to endanger pedestrians or street traffic. We also worked closely with our neighbors at ONEOK field to make sure our schedule would not impact events taking place.
During part of the project, we had three cranes on the site, which provided challenges in keeping personnel clear of swing space and ensuring the cranes had proper clearances from overhead powerlines. Ross Group also submitted for an Federal Aviation Administration (FAA) permit, where the FAA performed an Aeronautical Study to determine if cranes used for construction or the final building would impede any flight paths. Ross Group kept workers well informed about staying out of the swing radius of the cranes. We also developed and reviewed detailed crane plans so proper planning was accomplished before the crane was onsite.
The entire site was surrounded by powerlines, which required us to ensure that dump trucks and cranes arriving and leaving the site had adequate clearance so they wouldn’t hit overhead power lines. We managed this by incorporating spotters to watch and direct the trucks and cranes, while moving around the site.
Finally, heat stress was another issue on this project. The team and subcontractors were working inside a partially enclosed building with no air conditioning, so it was critical to monitor for heat related issues during the warmer months. Ross Group held numerous toolbox talks discussing signs of heat related illness and how to recognize it, such as taking breaks in cool shaded areas and staying aware of the symptoms of heat exhaustion.
What are some of the safety features incorporated into the design of the building?
We incorporated numerous safety features into the design of the building to ensure occupants’ safety once the building was operational. Some simple but essential safety features included installing tie-off points on the roof so that anyone working on top of the building can safely tie off and placing photo-luminescent (glowing) stickers in stairwells to assist with emergency evacuations. Some of the more complex features included:
Designing a fire command center on the first floor, which is an operational area that allows fire fighters to control the building systems in case of emergency. It has features such as controls for unlocking stair doors and communication plugins on every floor for fire fighters inside to talk to the fire fighters on the ground.
Since the building is over 75’, the design incorporated pressurizing the stairwells to keep smoke out of the stairwell, using positive pressure to blow smoke out.
A concern many people have is what happens if they are on an elevator when a fire breaks out. Typically, and what was designed for the Vast Bank building, if the fire alarm goes off the elevators are programmed to immediately return to the first floor. Smoke guards (sometimes called a smoke curtain) were installed at the first-floor evaluator doors to prevent smoke from wafting into the shaft, protecting people in the elevator in case of a fire. Smoke can’t enter the elevator, but people in the elevator are able to push it open to get out safely.
As you can imagine, we’ve barely covered the numerous safety features that are critical when designing and constructing high-rise buildings. To ensure that we take all facets of the project into consideration, Ross Group works closely with the design team from the beginning of the design phase all the way through project completion, so we can plan with safety in mind. Once the project moves to the construction phase, our Safety team is intricately involved to ensure everyone stays safe. The sooner these risks are mitigated and managed, the safer the building will be during construction for the workers and, once completed, for the occupants.