外文文献翻译 公寓建筑物的防火安全设计.docx

外文文献：THE FIRE SAFETY DESIGN OF APARTMENT BUILDINGSIn most fire engineered buildings, intervention of the fire brigade is not usually considered.The fire brigade provides the last line of attack on a fire, and usually the last opportunity tofind and rescue occupants. The intervention of the fire brigade is highly dependent on themreceiving an alarm or notification of a fire.The role of the fire brigade is important in an apartment fire as they can:I Fight, suppress and extinguish the firei ' Perform search and rescue operationsI ： Externally rescue occupantsControl evacuation via the EWIS system or liftsi ' Perform first aidReassure occupantsFor the fire brigade to perform their jobs properly they require:I . Adequate site access! Adequate water suppliesSuitably located fire system control centres and indicator panels Controls for liftsL Protection from structural failure for an appropriate length of timeThe Australian and New Zealand building codes and standards provide design criteria for theabove requirements. Successful fire brigade intervention can be achieved with pre-planning,early alarm, rapid response and the provision of sufficient labour and equipment to deal withthe hazard (Beck et al, 1992).The time for the fire brigade to arrive and extinguish the fire is influenced by the followingcomponents:U Time to detection of fire. Either by automatic systems or people (Buchanan, 1996). Time to notification of fire brigade (Buchanan, 1996). Fire brigade travel time (Buchanan, 1996).Access and search time for all floors (Buchanan, 1996).Act as a command point for the rescue personnel to assist the evacuation of the buildingI , Provide a place for disabled or partially disabled occupants to wait for assistance before being evacuatedAllow occupants to move to an alternative staircaseAllow smoke separation at the refuge level in the stair caseLo and Will (1997) also state that refuge floors can psychologically assist occupants under escape conditions. Refuge floors can psychologically relieve occupants by: Reassuring them that the height of escape is not too onerousI Providing an area for cognitive and decision control Seeing the presence of fire brigade personnelRefuge floors can also be used as a safe area where lifts are controlled and co-ordinated for egress. Passenger lifts not used on the fire floor can be used at the refuge floor to evacuate occupants (Lo and Will, 1997). High-rise buildings are usually broken up into low-rise, midrise and high-rise sections, with lifts that serve each section separately. To assist in rescue operations, lifts that do not serve the fire floor can be used for rescue and mobilisation of fire brigade personnel and equipment. The arguments against refuge floors (Lo and Will, 1997) are that:I They provide an additional cost to the building owner in terms of building cost and non-utilised space It can be difficult to maintain and enforce the use of refuge floors i ' There are already protected escape routesI Unless people have difficulty in escaping they are unlikely to remain on the refuge floorFor residential buildings, Lo and Will (1997) believe that refuge floors may be necessary to provide an area of safety if conditions become untenable due to long pre-movement times.Another approach to using refuge floors is to reduce the effective height of high-rise buildings (Teh, 1994). Since the height is directly proportional to egress time, the provision of adequately protected refuge areas can reduce the effective building height. Therefore once occupants have reached a refuge floor they can be considered to be safe. To achieve this The (1994) proposes the following requirements:i , Additional provisions to prevent smoke infiltration (smoke stopping of all vertical shafts)All lifts connecting to the refuge floor to be accessible through smoke lobbies r The refuge floor must be accessible at all times and capable of accommodating the projected number of peopleI A substantial part of the refuge floor is to be natural vented or capable of being naturally vented (ideally the refuge area should be a part of an external area) i ' The design and layout of exit stairs should discharge occupants into the refuge floor before they proceed further downi Pressurisation of exit stairs can be separated into vertical zones to avoid failures of the system affecting the whole stairRefuge floors in apartment buildings may assist the evacuation of occupants, but requirements of refuge floors need to be assessed against: other fire safety measures, the cost of a refuge floor and the emergency strategy. With the provision of sprinklers, compartmentation and smoke control, the need for a refuge floor in apartment buildings is questionable. Apartment buildings are generally fire separated between individual units, at each floor level and between escape paths. The areas that are fire separated from each other could be designed as refuge areas reducing the need for an entire refuge floor. Occupants also have option to remain in their apartments, where they have access to fresh air from windows.The cost of a refuge floor also needs to be considered in conjunction with the cost of other fire safety systems. The opportunity cost of a refuge floor is the: loss of rental space, loss of real estate and cost of maintaining the floor. These cost could easily outweigh the cost of a sprinkler system that may provide a higher level protection. In high-rise buildings fires, where smoke control systems have failed, a refuge floor withadequate natural cross ventilation, could have assisted occupant egress. The World Trade Centre bombing (Fahy and Proulx, 1996) and the MGM Grand fire (NFPA,1982a) are two possible cases where injury and fatalities may have been avoided, if the occupants were able to get to a refuge floor with adequate ventilation. In these two fires, exits were compromised by smoke and occupants were evacuating through poor conditions.In ultra high-rise buildings, defined as greater than 40 storeys (Lo and Will, 1997), refuge floors could be of some assistance for disabled, elderly and other occupants who need assistance to evacuate. However, these occupants may be better served through refuge areas on each floor or by the occupants remaining in their apartments. Lo and Will (1997) argue that refuge areas do not have the same psychological benefits for the escaping occupants, as a refuge floor, and therefore are not as effective.8.5.2 Refuge areasThe Acceptable Solutions to the NZBC (BIA, 1991) require refuge areas in apartment buildings greater than 58m high with intermediate floors. These refuge areas are to be located at intervals of no greater than 3 floors in the vertical safe paths, be at least 800mm wide and have an area of no less than 2m2. Guidance on refuge areas is also provided in British Standard BS5588 - Part 8, 1998 (BSI, 1988).The NFPA Life Safety Code (Cote, 1997) requires people with severe mobility impairment to have at least two means of accessible egress. One method to achieve this is through the provision of a compliant refuge area. The effectiveness of refuge areas is highly dependent on the design details. Some of details that need to be considered are fire exposure, reliability of the smoke control system, outside wind and temperature condition. Without pressurisation all refuge areas can be subject to lethal failure (Nelson, 1993 and Klote, 1993). r In many cases, the people needing the refuge areas may be unable to reach the area before their pathways become untenable (Nelson, 1993 and Klote, 1993) i ' The organisation and human behaviour problems involved with refuge areas are more complex (Nelson, 1993 and Klote, 1993).I ' The operation of a sprinkler system eliminates the life threat to all occupants and can provide superior protection for people with disabilities as compared to arefuge area. (Nelson, 1993 and Klote, 1993)Klote (1993) found pressurisation of refuge areas could be significantly influenced by, opening and closing of doors, window breakage and external wind pressures.Generally, refuge areas can be effectively pressurised by a direct pressurisation system or an indirect pressurisation system using lift shafts. But an indirect pressurisation system using the stairwell may not be effective or appropriate (Klote, 1993).8.6 LiftsThe use of lifts or elevators for emergencies is not a new concept, but they are typically only used with fire brigade assistance. In general, occupants are told not to use lifts in a fire. However, the fire brigade has often used lifts to rescue people and mobilise equipment. Lifts have also been used in hospitals to move non-ambulatory patients.The use of lifts for fire fighting and assisting rescue operations provides an efficient means of moving people and equipment. This is particularly important in high-rise buildings, where moving equipment takes time and uses valuable resources. An example of this was the First Interstate Bank, where lifts were not used, and a fire on the 12th floor required 100 men to carry equipment up the stairs (Degenkolb, 1991). The BCA requires buildings with an effective height greater then 25m to have one or more lifts, fitted as an emergency lift (Performance Requirement EP3.2, BCA, 1996). This is to facilitate the activities of the fire brigade and other emergency service personnel. In addition to this, stretcher facilities must be provided in at least one of those emergency lifts, or in a non emergency lift where the effective building height is greater than 12m.The British Standard BS 5588 - Part 8 1988 (BSI, 1988), provides guidance on the use of lifts for evacuation of disabled people. BS 5588 Part 8 provides guidance on the design of lifts used for evacuations as well as the management of evacuation lifts, and examples of fire plan strategies in buildings with evacuation lifts.The some of the problems with the use of lifts for egress are: i Pressurisation of shafts is not necessarily effective for smoke control (Klote et al,1993) Lift components can be affected by heat, smoke and water (Klote et al, 1993) Power failure (Klote et al, 1993)r. Potential of lifts opening onto the fire floorr The evacuation needs to be controlled and co-ordinated and the number of occupants entering the lift needs to be regulatedi ' Lift shafts can act as chimneys exposing occupants to heat and smoke.Occupants have been told for the last 20 years not to use lifts in a fire (Klote et al, 1993)i ' Pressure differentials in lift shafts can vary with building geometry and at different floors (Klote, 1983)I Lift microprocessor controls are very sensitive to heat (Semple, 1993)I Fire brigade shutting off the power can be a problem. Batteries will only run for a limited length of time (Semple, 1993).Malfunctions in an emergency could lead to litigation (Semple, 1993).L There is limited opportunity for rescue of people trapped between floors (Pauls et al, 1991)The some of the other reasons why lifts are unsafe stated in the ASME Elevator Code and Handbook A 17.1 (Cote, 1997) are:Occupants may push a button and waste valuable time waiting for a lift that may not arrive Lifts can not start until the car and hoistway (lift shaft) doors are closed. Overcrowding may prevent these doors from closingI ' A lift occupant could press the incorrect buttonNormal functioning of lifts such as high or low call reversal may occur at the fireFloorThe NFPA Life Safety Code (Cote, 1997) does not recognise lifts as a typical means of escape, but it does allow their use under certain circumstances. If a lift complies with Section 7-4 of the Code, it is permitted as a second means of egress, provided: i The building and surrounding structure is protected throughout by an automaticsprinkler system The building is subject to an occupancy of no more than 90 peopleI , Primary egress discharges directly to the outsider There are no high hazard content areas in the building or attached structures 100% of the egress capacity shall be provided independent of the lifts An evacuation plan is implemented specifically including the liftThe most immediate application for the use of lifts, in the evacuation of apartment buildings, is for the evacuation of disabled and elderly occupants and the evacuation of low occupancy high-rise apartments.The escape times for lift egress can be calculated from the following formula (Klote et al,1993)Klote et al (1993) found that the use of lifts for egress decreases building evacuation times by between 10 and 50%. Greater evacuation efficiency occurs as the height of the building increases. The time-savings are a result of using a combination of lifts and stairs for evacuation. A similar result was found by Andersson and Wadensten (2000), in their simulations of the One Canada Square building at Canary Wharf in London, where they found that lifts improved the evacuation procedures in the building.The following are 13 criteria for safe lift egress design proposed by Chapman (1994) 1. The building be fully sprinkler protected2. Lift shafts should be pressurised3. Lift lobbies on all floors should be enclosed4. Lift lobbies should be pressurised5. Lift and lobby pressurisation intakes should be in a smoke free location6. All lift lobbies should be protected by smoke detectors7. Lift systems should be made water resistant8. When a power failure occurs all lifts should return to their designated level9. All lifts should be able to be operated from a designated emergency power generator10. All lift lobbies should have access to a pressurised stair, without the occupants having to pass through a fire area11. All lift cars should have a means of two way communication12. All lift lobbies should have a means of two way communication13. A program specifying the priority of lift response during a fire should be developed.For lifts to be effective in evacuations, some other design concepts that should be considered are:Smoke and fire separation of lift machine room and lift shaft (Klote, 1993, Klote et al, 1995, Levin and Groner, 1994)Analogue addressable detection system linked to lift control to prevent lift stopping on fire floors and to prioritise floors for evacuation (Klote et al, 1995, Levin and Groner, 1994) Automatically recall lift if a fault is detected (Klote, 1993, Klote et al, 1995, Levin and Groner, 1994)Wardens or security staff to direct evacuations, reassure occupants and prioritise who uses the lifts, and also to control occupant numbers in the lifts (Klote et al, 1995, Levin and Groner, 1994) Provide a system to prevent the lift stopping on floors where heat is detected, or providing fire rated lobbies on all floors (Klote et al, 1995, Levin and Groner, 1994) Higher levels of protection for lift system, if building