Fire Safety for Very Tall Buildings

Very tall buildings have unique hearth safety design issues that aren’t skilled in different kinds of structures. For example, as a end result of the peak of the construction is past the reach of ladders, tall buildings are geared up with more fireplace security options as it is not attainable for the hearth department to initiate exterior rescues from ladders and suppress fires with exterior hose streams.
In regards to fire security, the performance history of very tall buildings while very profitable, has not been with out catastrophic incidents. Many of those incidents have resulted in 1) numerous deaths and injuries, 2) excessive property loss and 3) disruptions in business continuity. For example, the One Meridian Plaza high-rise fireplace in Philadelphia that occurred in 1991 resulted within the lack of three firefighters and building by no means being re-opened. In 1988, the hearth within the Interstate Bank Building in Los Angeles experienced one fatality and resulted in the building being out of use for six months.
Based on research and lessons discovered, the mannequin building codes have made significant progress in addressing hearth safety issues in very tall buildings. At the identical time, the complexity and distinctive challenges of today’s very tall buildings have created an setting where complete performance-based options have become a necessity.
To help the design neighborhood with developing performance-based fire safety solutions for very tall buildings, in 2013, the Society of Fire Protection Engineers (SFPE) partnered with the International Code Council (ICC) to develop the Engineering Guide: Fire Safety in Very Tall Buildings.1 This publication is written as a guide for use at the side of native codes and requirements and serves as an added tool to these concerned within the fireplace protection design of distinctive tall buildings. The information focuses on design issues that have an effect on the fire safety performance of tall buildings and the way engineers can incorporate performance-based fire safety through hazard and risk evaluation methodologies into the design of tall buildings. This article will talk about a few of the distinctive fire safety design strategies/methodologies employed in the design of tall buildings which might be referenced in the ICC/SFPE Guide.
Emergency Egress
Developing an efficient evacuation strategy for a tall constructing is difficult as the time to complete a full building evacuation will increase with building peak. At the identical time, above sure heights, the normal technique of requiring all occupants to simultaneous evacuate may not be practical as occupants turn into extra susceptible to further risks when evacuating by way of stairways. That is why tall buildings usually employ non-traditional or various evacuation strategies.
When designing an egress plan for a tall constructing, the first objective should be to provide an applicable means to allow occupants to maneuver to a place of safety. To accomplish this goal, there are several evacuation methodologies which would possibly be out there to the design staff. These evacuation methods can embody however aren’t restricted to 1) defend-in-place, 2) transferring folks to areas of refuge and 3) phased/progressive evacuation. It is also possible that a combination of these methods could be this best resolution. When deciding on an appropriate technique, the design team ought to think about the required stage of safety for the constructing occupants and the constructing performance aims that are recognized by the building’s stakeholders.
Using protected elevators has become another evacuation strategy that is turning into more prevalent in the design of tall buildings. In addition to assisting the fire department with operations and rescues, protected elevators at the moment are getting used for constructing evacuation, particularly for occupants with disabilities. When contemplating elevators in an evacuation technique, there are a variety of design considerations to think about: 1) security and reliability of the elevators, 2) coordination of elevator controls and building safety systems, 3) training of constructing occupants and first responders and 4) communication to building occupants through the emergency.
Tall buildings often employ non-traditional or different evacuation methods.
Fire Resistance
The penalties of partial or international collapse of tall buildings as a outcome of a severe hearth pose a significant danger to a large quantity of folks, the fireplace service and surrounding buildings. At the identical time, tall buildings usually have unique design features whose role in the structure and fire response usually are not simply understood using conventional fireplace protection methods. These unique elements could warrant a need to adopt a complicated structural fire engineering analysis to demonstrate that the building’s efficiency goals are met.
Performance-based design of structural hearth resistance entails three steps: (1) willpower of the thermal boundary conditions to a structure ensuing from a hearth; (2) calculation of the thermal response of the construction to the fireplace exposure, and (3) willpower of the structural response of the structure. Guidance on performing this kind of analysis could be found in the SFPE Engineering Standard on Calculating Fire Exposures to Structures2, and SFPE Engineering Standard on Calculation Methods to Predict the Thermal Performance of Structural and Fire Resistive Assemblies.three
Water-Based Fire Suppression Systems
In tall buildings, the water supply required for fire safety systems could be higher than the aptitude of the public water provide. As such, fire protection system water provides for sprinkler systems and standpipes require using pumps and/or gravity water tanks to boost the water strain. Reliability of this water provide is a key consideration. As such, redundant fire pumps, gravity-based storage supplies, or each may be wanted to reinforce system reliability.
Another issue to consider when designing water-based fire suppression systems is pressure control as it is possible for system components to be uncovered to pressures that exceed its most working stress. Consequently, it could be essential to design vertical pressure zones to regulate pressures within the zone. Additionally, strain regulating valves are sometimes needed. When installed, care must be taken to ensure that these stress regulating valves are installed properly and adequately maintained.
Fire Alarm and Communication Systems
Providing building occupants with correct info during emergencies will increase their ability to make appropriate selections about their very own safety. Fire alarm and communication methods are an necessary source of this info. Very tall buildings employ voice communication systems which would possibly be built-in into the hearth alarm system. When designing voice communication methods you will want to be certain that the system supplies dependable and credible data.
Fire alarm system survivability is one other import factor to contemplate in fire alarm system design. For tall buildings, consideration ought to be given so that an attack by a fire in an evacuation zone does not impair the voice messaging exterior the zone. Some of the design concerns to attain survivability could embody: 1) safety of control equipment from hearth, 2) protection of circuits. 3) configuration of circuits and 4) shielding of panels.
Tall buildings usually employ smoke control systems that either vent, exhaust or restrict the spread of smoke.
Smoke Control
Controlling the unfold of smoke is more difficult in tall buildings. For instance, tall buildings experience a phenomenon called stack effect. Stack effect occurs when a tall constructing experiences a stress difference throughout its height as a result of temperature differentials between the skin air temperature and the inside constructing temperature. This causes air to maneuver vertically, relying on the outside air temperature – either upward or downward in a building. It also can cause smoke from a constructing fire to unfold all through the constructing if not controlled. That is why tall buildings often employ smoke administration systems that both vent, exhaust or restrict the spread of smoke.
Other issues in tall buildings included the air motion created by the piston impact of elevators and the effects of wind. เครื่องวัดแรงดันเกจที่นิยมใช้ to elevator automobiles ascending and descending in a shaft and the effects of wind can lead to smoke movement in tall buildings. These impacts turn into more pronounced as the height of the building enhance.
Because very tall buildings complicate smoke spread, effective smoke management is more difficult to achieve. The potential solutions are numerous and embody a mixture of energetic and passive features corresponding to however not limited to: 1) smoke barrier walls and flooring, 2) stairway pressurization techniques, 3) pressurized zoned smoke management provided by the air-handling gear, and 4) smoke dampers. The answer carried out into the design wants to handle the building itself, its uses, relevant occupant traits and reliability.
First Service Issues
It goes without saying that tall buildings present distinctive challenges to the fireplace service. During the planning and design phases, it is important for the design staff to work with the fireplace service to debate the kind of resources which would possibly be wanted for an incident and the actions that shall be wanted to mitigate an incident. This consists of developing building and post-construction preplans. These preplans ought to include and not be limited to creating provisions for 1) hearth service access together with transport to the best stage of the building, 2) establishing a water supply, 3) standpipe methods (temporary and permanent), 4) communication methods, and 5) understanding the operations of the hearth safety systems in the constructing.
One of the challenges the fire service faces during incidents in tall buildings is the power of firefighters to move tools to the incident location. Designers ought to bear in mind how the hearth service can transport its tools from the response degree to the very best level in a safe manner.
Additionally, care must be taken when designing the hearth command center as it’s going to provide the fire service command workers with essential details about the incident. The hearth command heart needs to be accessible and should embrace 1) controls for constructing systems, 2) contact information for constructing management, 3) present buildings plans, 4) emergency response and egress plans and 5) preplans.
1 International Code Council/SFPE. (2013). Engineering Guide: Fire Safety for Very Tall Buildings. Country Club Hills, IL.
2 SFPE. (2011). SFPE Standard S.01 2011, Engineering Standards on Calculating Fire Exposures to Structures. Gaithersburg, Maryland.
three SFPE. 2015). SFPE Standard S.02 2015, SFPE Engineering Standard on Calculation Methods to Predict the Thermal Performance of Structural and Fire Resistive Assemblies. Gaithersburg, Maryland.
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