Fire Safety for Very Tall Buildings

Very tall buildings have distinctive hearth safety design points that aren’t experienced in different forms of buildings. For example, as a end result of the peak of the structure is beyond the reach of ladders, tall buildings are geared up with extra fire safety features as it’s not possible for the hearth division to provoke exterior rescues from ladders and suppress fires with exterior hose streams.
In regards to fire security, the efficiency historical past of very tall buildings while very profitable, has not been with out catastrophic incidents. Many of those incidents have resulted in 1) quite a few deaths and accidents, 2) excessive property loss and 3) disruptions in enterprise continuity. For instance, the One Meridian Plaza high-rise hearth in Philadelphia that occurred in 1991 resulted within the lack of three firefighters and constructing never being re-opened. In 1988, the hearth within the Interstate Bank Building in Los Angeles experienced one fatality and resulted within the building being out of use for six months.
Based on analysis and lessons learned, the model building codes have made vital progress in addressing fire issues of safety in very tall buildings. At the same time, the complexity and distinctive challenges of today’s very tall buildings have created an setting where complete performance-based solutions have become a necessity.
To help the design neighborhood with creating performance-based hearth safety options 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 to be used in conjunction with native codes and requirements and serves as an added device to those concerned within the fireplace protection design of unique tall buildings. The information focuses on design issues that have an effect on the fireplace safety efficiency of tall buildings and how engineers can incorporate performance-based fire safety by way of hazard and threat analysis methodologies into the design of tall buildings. This article will focus on a few of the distinctive fire security design strategies/methodologies employed within the design of tall buildings which may be referenced within the ICC/SFPE Guide.
Emergency Egress
Developing an effective evacuation strategy for a tall building is challenging as the time to finish a full constructing evacuation will increase with constructing peak. At the identical time, above sure heights, the standard technique of requiring all occupants to simultaneous evacuate is most likely not practical as occupants turn into more susceptible to further risks when evacuating by way of stairways. That is why tall buildings typically make use of non-traditional or alternative evacuation strategies.
When designing an egress plan for a tall constructing, the primary goal must be to provide an acceptable means to permit occupants to maneuver to a spot of security. To accomplish this objective, there are several evacuation methodologies that are out there to the design team. These evacuation strategies can embody but are not restricted to 1) defend-in-place, 2) transferring folks to areas of refuge and 3) phased/progressive evacuation. It can additionally be potential that a mixture of these strategies may be this finest solution. When deciding on an applicable strategy, the design group should contemplate the required degree of safety for the constructing occupants and the constructing performance goals that are identified by the building’s stakeholders.
Using protected elevators has turn out to be one other evacuation technique that is turning into extra prevalent in the design of tall buildings. In addition to helping the hearth division with operations and rescues, protected elevators are now getting used for constructing evacuation, significantly for occupants with disabilities. When contemplating elevators in an evacuation technique, there are a selection of design considerations to suppose about: 1) safety and reliability of the elevators, 2) coordination of elevator controls and constructing safety systems, 3) training of constructing occupants and first responders and 4) communication to constructing occupants through the emergency.
Tall buildings typically employ non-traditional or various evacuation strategies.
Fire Resistance
The penalties of partial or global collapse of tall buildings as a end result of a extreme hearth pose a big danger to a lot of individuals, the fire service and surrounding buildings. At the same time, tall buildings usually have unique design options whose position in the construction and hearth response are not simply understood utilizing conventional hearth safety methods. These unique factors may warrant a must undertake a complicated structural hearth engineering evaluation to reveal that the building’s performance aims are met.
Performance-based design of structural fireplace resistance entails three steps: (1) willpower of the thermal boundary conditions to a construction ensuing from a fire; (2) calculation of the thermal response of the construction to the fireplace exposure, and (3) willpower of the structural response of the construction. Guidance on performing this sort of evaluation could be found within 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 can be greater than the capability of the basic public water provide. As such, hearth safety system water provides for sprinkler methods and standpipes require the usage of pumps and/or gravity water tanks to boost the water pressure. Reliability of this water supply is a key consideration. As such, redundant fire pumps, gravity-based storage supplies, or each may be wanted to boost system reliability.
Another problem to consider when designing water-based hearth suppression methods is stress control as it is potential for system components to be exposed to pressures that exceed its most working stress. Consequently, it could be essential to design vertical strain zones to manage pressures in the zone. Additionally, strain regulating valves are sometimes wanted. When put in, care must be taken to make sure that these stress regulating valves are installed properly and adequately maintained.
Fire Alarm and Communication Systems
Providing building occupants with accurate info during emergencies will increase their ability to make appropriate choices about their own safety. เครื่องมือที่ใช้วัดความดันเลือด and communication methods are an essential supply of this info. Very tall buildings employ voice communication techniques which would possibly be integrated into the fire alarm system. When designing voice communication systems you will want to ensure that the system provides reliable and credible data.
Fire alarm system survivability is another import factor to consider in fireplace alarm system design. For tall buildings, consideration ought to be given in order that an attack by a hearth in an evacuation zone doesn’t impair the voice messaging outside the zone. Some of the design considerations to realize survivability could embody: 1) safety of control tools from hearth, 2) protection of circuits. 3) configuration of circuits and 4) shielding of panels.
Tall buildings typically employ smoke control systems that either vent, exhaust or restrict the spread of smoke.
Smoke Control
Controlling the spread of smoke is more difficult in tall buildings. For instance, tall buildings experience a phenomenon referred to as stack effect. เกจวัดแรงดันออกซิเจนราคา occurs when a tall constructing experiences a pressure distinction throughout its top as a outcome of temperature differentials between the skin air temperature and the inside building temperature. This causes air to move vertically, depending on the surface air temperature – both upward or downward in a constructing. It can even cause smoke from a constructing fireplace to unfold all through the building if not managed. That is why tall buildings typically make use of smoke administration techniques that both vent, exhaust or limit the unfold of smoke.
Other concerns in tall buildings included the air movement created by the piston effect of elevators and the consequences of wind. Air movement brought on by elevator cars ascending and descending in a shaft and the results of wind can result in smoke motion in tall buildings. These impacts become more pronounced as the peak of the building improve.
Because very tall buildings complicate smoke unfold, efficient smoke management is tougher to achieve. The attainable solutions are quite a few and embrace a mixture of lively and passive options similar to however not limited to: 1) smoke barrier partitions and flooring, 2) stairway pressurization methods, 3) pressurized zoned smoke management supplied by the air-handling equipment, and 4) smoke dampers. The resolution carried out into the design needs to handle the constructing itself, its makes use of, relevant occupant traits and reliability.
First Service Issues
It goes with out saying that tall buildings current distinctive challenges to the hearth service. During the planning and design phases, it is important for the design group to work with the fireplace service to discuss the kind of sources which might be needed for an incident and the actions that will be wanted to mitigate an incident. This includes developing development and post-construction preplans. These preplans should embody and never be restricted to creating provisions for 1) fireplace service entry together with transport to the best degree of the constructing, 2) establishing a water provide, 3) standpipe methods (temporary and permanent), 4) communication techniques, and 5) understanding the operations of the fireplace protection techniques within the constructing.
One of the challenges the fireplace service faces throughout incidents in tall buildings is the ability of firefighters to move equipment to the incident location. Designers should keep in mind how the hearth service can transport its tools from the response degree to the best stage in a protected method.
Additionally, care must be taken when designing the hearth command middle as it’s going to provide the fire service command workers with important information about the incident. The fireplace command center must be accessible and may embrace 1) controls for constructing methods, 2) contact data 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.
3 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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