Guidelines for Designing Fire Safety in Very Tall Buildings - Quiz

Quiz Question

1.	The World Trade Center attack in 2001 caused enhanced interest in the challenges of tall buildings. Which one of the below would be considered a challenge:
		Egress and evacuation
		Emergency access
		Communications / situation awareness
		Fire resistance / resiliency
		Reliability of water supply and active fire protection systems
		All of the above
2.	A number of methods are available for reducing the amount of time required to evacuate a building during a fire event. Some of these methods involve physical systems, whereas some may require management strategies or a combination of both. The selection of such methods requires consideration that each works to appropriately complement one another such as Exit Discounting Horizontal Stair Transfers Effective Wayfinding/Exit Signage
		True
		False
3.	Egress plans should be documented in the fire protection design report. The building’s stakeholders should participate in its development. In the case of a __________, there may be many stakeholders, such as the owner, property manager, fire safety director, occupant and tenant representatives and building engineers. The emergency responders such as the police and fire department should be involved.
		Tall building
		Average building
4.	In general, as buildings go beyond approximately 30 stories, lateral resistance to address drift and accelerations becomes an increasing concern due to wind. Traditional lateral resisting systems, such as moment frames, for low- to medium-rise buildings become less efficient and less economical as the building height increases. Additional structural systems, such as outriggers, tuned mass dampers and/or visco-elastic dampers, are typically required to help address the increased lateral resistance demand. Oftentimes, these systems can influence the demands on the load-resisting systems (both gravity and lateral) of the building, and therefore become an integral part of the overall global stability system of the building. In addition, these systems may consist of combustible materials that may degrade in a fire or contribute to fire severity. Consideration needs to be given on how fire will affect the material response of these systems locally and globally, and what level of fire resistance or protection is appropriate to maintain global stability and other performance objectives.
		True
		False
5.	The occurrence of fire following an earthquake is a potential concern for all structures, not just very tall buildings. Water supplies, automatic sprinkler systems, emergency power and fire department intervention may be limited or disrupted after a major earthquake. However, for very tall buildings, because of the potential remoteness of the fire floor from grade level, it may take more time for emergency fire fighting activities to occur. This may mean that a fire on the upper floors could go unchecked for several hours and potentially travel to multiple floors. Consideration should be given to the impact of a fire on the performance of the structure post-earthquake. This may consist of a post-earthquake fire risk assessment, structural fire analysis of various fire scenarios (e.g. fully-developed post flashover fire over a single floor, multiple floor fires, travelling fires, etc.), providing additional fire safety provisions to mitigate fire ignition or spread, etc.
		True
		False
6.	In tall buildings, a higher level of resiliency and robustness may need to be considered in determining the type of fire resistance materials used to protect the structure. More robust fire protection materials may be warranted due to the increase in consequences of partial or global collapse of the structure, the increase in egress times for building occupants, and the increase in time for fire personnel to conduct fire fighting activities. For example, concrete is a _________ fire protection material with respect to durability, damage, maintenance etc, in comparison to, spray applied fire protection material, which can be more susceptible to physical damage, water damage, maintenance etc. The advantages of a more robust fire protection material will need to be weighed against other drivers in the design (e.g. weight, cost, aesthetics, sustainability, etc.), in order to identify an appropriate solution.
		More robust
		Less robust
7.	The three principal mechanisms at work in Figure 12.3 are as follows: Inside – Flames and fire gases in the building attack the interior surfaces and details of the curtain wall and associated perimeter fire barrier materials. Outside – Flames and hot gases projecting from fire-broken glazing or other openings directly impinge on the curtain wall exterior face (convection). Flame impingement on the architectural cladding system may ignite combustible components of the cladding system if not appropriately isolated/protected. Outside – Flames projecting from fire-broken glazing or other openings radiate heat to and through glazed surfaces or through other openings to building contents and furnishings.
		True
		False
8.	Fire resistance is the ability of a structural element or system to withstand exposure to fire such that load-bearing capacity, integrity and insulation are maintained for a specified duration. Traditionally, the fire resistance of a structure is demonstrated via standardized fire testing where single elements of structure are exposed to an infinitely increasing standard fire curve (e.g. ASTM E119,69 BS 476:20,70 ISO 83471) and assessed against prescribed temperature and integrity limits. While this approach has historically satisfied life-safety objectives, it is _____whether these objectives, let alone other performance objectives, will be satisfied as buildings become larger, taller, and more complex.
		Unclear
		clear
9.	At high temperatures, concrete structures can undergo varying degrees of spalling – the deterioration and breakdown of the concrete causing layers of material to separate from the structure. In fire conditions, spalling can be progressive (due to a gradual rise in temperatures) or explosive in nature where there is a sudden loss of large portions of the concrete surface.
		True
		False
10.	Fire detection and alarm systems are intended to provide notification of fire events within the buildings in which the systems are installed. They provide early warning notification to building occupants and notification of fire events for both on- and off-site emergency response personnel. They also provide control of fire safety functions for fans and dampers to reduce smoke spread , recall and shutdown elevators and control fire doors.
		Not True
		True
11.	Fire detection is provided through initiating devices such as heat detectors, smoke detectors, flame detectors and other fire-related detection devices. Fire alarm systems also monitor extinguishing systems such as automatic sprinklers, gaseous agents and other extinguishing agents. Recognition of a fire event can also be provided by building occupants via manual fire alarm stations. All of these input devices provide an indication that a fire event may be present within a facility. These input functions also serve to initiate specific output functions.
		True
		False
12.	For very tall buildings a large portion of the fire alarm and emergency evacuation system will likely be in non-fire areas. Therefore, it is important to consider system operability during fire and emergency events. For very tall buildings, it is important to have a system operate in nonfire areas even though a fire may impact a portion of the system. Designs can include measures to improve the survivability of the fire alarm system panels and circuits within the building. Which one of the followings would be considered design considerations:
		Protection of panels from fire.
		Protection of fire alarm circuits from fire.
		Configuration of fire alarm circuits.
		Shielding of panels.
		All of the above
13.	Smoke control is incorporated in the overall fire strategy in many different building types, independent of size. However, the matter of smoke spread and smoke control is a little more complicated in tall buildings. Their inherent geometry, occupant distribution, the physics of smoke flow and the characteristic design features such as extensive networks of shafts, complex ventilation systems and spatial interconnections makes for a structure potentially more vulnerable to smoke spread and its negative consequences. Refer to the SFPE Handbook of Fire Protection Engineering,103 the Principles of Smoke Management,104 the Fire Protection Handbook105 or the ASHRAE Handbook for specific details.
		True
		False
14.	Another concern, found in high rise buildings is the air movement created by the piston effect of elevators. The air movement caused by the elevator cars ascending or descending within the shafts can force air through the elevator shaft doors into the floor space. Alternatively, the same effect can create a ______ effect and draw smoke into the shaft. This can create a path and pumping system for smoke to move between floors. This effect is pronounced taller buildings when higher speed elevators are employed.
		Suction
		discharge
15.	HVAC systems can play a role in smoke spread. Normal use of the tall buildings can cause conditions that transport smoke due to mechanical forces generated by building services. Heating, ventilation and air conditioning systems (HVAC) can spread smoke by extracting smoke from the fire compartment and re-circulating in adjacent compartments, and by over pressurizing the fire compartment pushing the smoke through gaps and openings.
		Spread
		suppress
16.	For very tall buildings with manually operable windows, where windows are expected to be open on the windward side of the fire floor, wind effects can pressurize a “fire floor” resulting in increased smoke production and increased smoke spread concern. Conversely, if a zoned smoke control system is designed and implemented to offset such conditions (i.e., offset the positive force of the wind by exhausting the fire floor zone in alarm), the floors with operable windows above and below the fire floor can cause additional challenges. If the floors above and below have operable windows open on the leeward sides of the building, the floors may become “negative” relative to the fire floor between them, and may draw smoke into their spaces. However it is unlikely that a fire will occur during a windy day on the floor with operable windows open only on the windward side, and operable window on adjacent floors only open on the leeward side.
		True
		False
17.	The benefit of using helicopters for first response is the ability to deliver personnel and equipment to the upper portions of a building, avoiding delays caused by climbing stairwells or impairments with elevators or lifts. For very tall buildings, this approach could reduce response time. However, landing of a helicopter on the roof of a burning building is, in itself, a dangerous operation. Lack of visibility due to smoke and high winds could cause the helicopter to crash which would exacerbate an already dangerous situation.
		True
		False
18.	Many life safety systems require power to operate. The integrity of the power supply needs to be evaluated for very tall buildings. Many building and electrical codes govern which systems require secondary power and what type of power they need. Loads are subdivided, so that those most directly impact preservation of life and safety are given the highest priority. Typically these include: Emergency power. Standby power. Optional standby power.
		True
		False
19.	The time required to initiate emergency power after loss of loss normal power affects the performance of the life safety systems and therefore needs to be determined. During loss of normal power, batteries can be used on some equipment to maintain operation during switchover. Other systems will have a temporary loss of power until emergency or standby power can be provided.
		True
		False
20.	Some systems will tolerate a very short switchover to emergency power, while other systems can have a longer duration of power loss. Generally, emergency power is provided within 10 to 15 seconds, whereas standby power is provided within 60 seconds, based on many of the standards and codes used around the world. Emergency systems for high-rise and very tall buildings include the following: Exit signs and means of egress illumination. Elevator car lighting. Fire detection and alarm systems. Emergency voice alarm and communication systems. Electrical fire pumps.
		True
		False
21.	Standby power is typically required to be available after power is provided to emergency equipment. For very tall buildings, which one of the items below might need standby power:
		Elevators.
		Smoke control systems.
		Power and lighting for Fire Command Rooms.
		All of the above
22.	Optional standby power systems can also be connected to on-site emergency generators. It might be prudent to ______ optional equipment from code required standby systems.
		Separate
		Include
23.	The location of the generators should be determined. Generators located within the building should be located in rooms provided with ________ to the level of protection afforded by the surrounding building elements, such as floor assemblies. They should be located where access is reasonably provided and away from other potential hazards. If located outside the building, protection of the generators as well as the fuel supply from vehicular or other damage needs to be provided. Survivability and separation of power sources should be a fundamental design philosophy.
		Fire-resistance
		elevator
24.	One of the systems requiring emergency power is emergency lighting. This includes power to operate exit signs and means of egress illumination. If normal power is interrupted, minimum lighting levels are needed for safe egress as well as for emergency response personnel. Power for emergency lighting, as well as exit signage, can come from on-site generators or from batteries. The time to establish egress illumination should be included in the fire strategy. For a very tall building, this power normally comes from on-site generators, as they are already provided. For buildings without generators, backup power comes from battery packs integral to the sign or light. As noted above, the integrity of the emergency power system is a factor in the operation of emergency lighting and signage under loss of normal power conditions.
		True
		False
25.	Fires can occur in a very tall building during construction. Buildings under construction present fire protection risks that are often overlooked. These risks are magnified in very tall buildings, suggesting that a risk analysis is recommended for each project. The risk analysis may drive the need to plan for activating fire protection systems as the building is constructed. Awareness of emergency conditions is critical to the successful evacuation of persons from a very tall building. However, some parts of the designed building’s egress systems, as well as other passive and most of the active systems, are likely not operational at points during construction of a building. Construction phasing plans need to be coordinated with the life safety systems because of the number of workers that can be present within the building as it nears completion.
		True
		False