【正文】 THE FIRE SAFETY DESIGN OF APARTMENT BUILDINGS 13 FIRE SAFETY MATRIX The objective of this fire safety matrix is to provide a guide for the fire engineering design of apartment buildings. The matrix is only intended for guidance and an appropriately qualified fire safety engineer should verify the final design. The three main fire scenarios that should be considered in the design of apartment buildings are: a smouldering fire in an apartment, a flaming fire in an apartment and a fire in mon spaces (ie stairs and corridors). Irrespective of the building and occupant characteristics, some minimal fire safety measures should be implemented in all apartments. The following is a list of essential fire safety measures that should be provided in all apartment buildings: ??Smoke detectors ??Heating, ventilation and air conditioning (HVAC) system to shut down on fire alarm ??A 30minute minimum fire resistance between apartments, vertical shafts and floors. Emergency strategy Brief descriptions of the emergency strategy, or emergency plans used in the matrix are provided below. ??Evacuation – on alarm all occupants evacuate the building. ??Non evacuation – occupants in the room of fire origin evacuate the building. Other occupants remain in their rooms, waiting for fire brigade assistance and advice, and carry out protectinplace activities. ??Staged evacuation – occupants in the room of fire origin and on the fire floor evacuate first. The remaining occupants are directed to evacuate automatically in the following sequence until the fire brigade intervenes. Occupants immediately above the fire floor evacuate after those on the fire floor, followed by the floors above. Occupants on levels below the fire floor are evacuated last. Fire brigade intervention can alter the sequence of evacuation, or halt the evacuation in response to current conditions or any changes. Occupants at risk For the three fire scenarios and the three emergency strategies, the following matrix outlines the occupants that are most at risk. Matrix variables The fire safety design of apartment buildings consists of numerous variables and interdependencies. These variables have to be considered concurrently to provide the most effective design. The selection of fire safety measures in many cases results in a tradeoff between various alternatives. For example, sprinkler protection can permit a reduction in fire resistance rating required for buildings and may allow extended travel distances. These tradeoffs and interrelationships between fire safety measures need to be considered to obtain the most efficient and effective fire safety design. Table 14 lists some of the fire safety measures that should be considered for apartment buildings. The variables presented are not a prehensive list, and other fire safety measures may be more appropriate for more plex designs. Table 14 – Matrix variables Buildings greater than 25m The fire safety matrix for buildings greater than 25m high is presented in Table 15. The matrix provides the remended fire safety measures for apartment buildings with respect to sprinkler protection and the emergency strategy. The matrix provides a simple method of determining some of the minimum fire safety requirements of an apartment building. It can also be used to evaluate which type of emergency strategy would be most effective, or when sprinklers would be beneficial given certain building conditions. The justification of the remended fire safety measures is pvided in Section . Table 15 – Fire safety matrix: buildings greater than 25m the above matrix are designed to provide at least two levels of protection for the occupants. As the building height increases, the number of fire protection measures also increases to provide additional levels of protection and maintain the level of safety for the occupants. Table 16 summarises the occupants who are most at risk and the levels of fire safety provided by the above fire safety matrix. Table 17 provides the cell key for identifying the designated cells in Table 16. This key remains the same for all cases presented. Table 16 – Levels of fire safety (buildings greater than 25m) Table 17 – Cell key Buildings greater than three storeys and less than 25m The fire safety matrix for buildings greater than three stories and less than 25m high is presented in Table 18. The justification of the remended fire safety measures is provided in Section . Table 18 – Fire safety matrix: buildings greater than three storeys and less than 25m Table 19 – Levels of fire safety (buildings greater than three storeys and less than 25m) Buildings less than three storeys The fire safety matrix for buildings less than three stories is presented in Table 20. The justification of the remended fire safety measures is provided in Section . Table 20 – Fire safety matrix: buildings less than three storeys Table 21 – Levels of fire safety (buildings less than three storeys) 14 DISCUSSION OF FIRE SAFETY MATRIX The fire safety matrix considers the building height, sprinkler protection and the emergency strategy as the primary variables. This is due to the high influence that the interactions of these variables have on other fire safety measures. In addition to this, the fire engineer can specify the emergency strategy and sprinkler protection for the building that will provide flexibility to the matrix. Therefore once the extent of these three variables has been determined the remaining fire safety systems can be selected to suit the building. The objective of the fire safety remendations is to address key issues that result from a given set of building characteristics, while providing multiple levels of protection for occupants in the event of a fire. This provides a backup or redun