【文章內(nèi)容簡介】 emergency strategy relies on occupants escaping quickly. Without fire rated stair shafts the occupants have to travel a relatively short unprotected distance to make final also need to be protected in their apartments before they attempt to escape. In a sprinkler protected building the levels of protection are: 1. The sprinkler system. 2. Compartmentation and mechanical systems. The apartments are remended to have a FRR of at least 30 minutes to protect the occupants before and during their egress. There should also be a FRR of 30 minutes in the corridors and stairs, if egress distance is in excess of the building code’s prescriptive requirements. 3. The final level of protection is the fire brigade. In a nonsprinkler protected building the levels of protection are 2 and 3, as listed above, however the following other fire safety measures will be introduced to increase the level of protection: 1. The FRR will be increased to at least 60 minutes. This will ensure the fire does not spread further than the apartment of origin. 2. Selfclosers and smoke seals will be provided on all doors. This is to contain the fire in the apartment of origin and reduce smoke spread into other apartments. 3. A connection to the fire brigade will be provided to achieve a faster response. . Nonevacuation in buildings less than three storeys A nonevacuation strategy relies on the protection of occupants in their apartments. For buildings less than 3 storeys the fire brigade can rescue occupants externally via ladders and fight the fire externally. In a sprinkler protected building the levels of protection are: 1. The sprinkler system. 2. Compartmentation and mechanical systems. The rooms are remended to have a FRR of at least 60 minutes and to protect the occupants. The fire resistance rating will be designed so that the plete burn out of the apartment will not result in further fire spread. Selfclosers and smoke seals will be provided on all doors. This is to contain the fire in the apartment of origin and reduce smoke spread into other apartments. 3. The final level of protection is the fire brigade. The building will be connected to the fire brigade to reduce the time for fire brigade arrival. In a nonsprinkler protected building the levels of protection are 2 and 3, however the following other fire safety measures will be introduced to increase the level of protection: 1. The fire resistance rating will be increased to a minimum of 90 minutes to ensure the fire does not spread further than the apartment of origin. 4 Risk and Reliability The assessment of the absolute risk to life safety to apartment building occupants is an extremely difficult task. The numerous scenarios, variables, limited data and changes in the risk to life safety during a fire incident, makes an assessment of occupant risk very of the eight elements in Figure 1 will have an impact on the risk to life safety and this level of risk will change during a fire incident. For example occupants on level of fire origin will have a relatively high risk, but if they move below the level of fire origin their risk to life safety will decrease. An assessment of the relative risk to life safety is a more feasible option, but again the numerous variables and limited data makes this difficult. Previous research by Beck and Yung (1990) used a risk assessment model to assess the expected risk to life and fire cost expectations of apartment buildings relative to the building code. An assessment of the relative life safety is simpler, and in some cases intuitive. In many instances, a qualitative relative risk assessment can be made. For example, given the same building, sprinkler protection would be safer than no sprinkler protection. However, a relative assessment of life safety bees more plex if different fire safety systems are assessed against each other. For example, is a building with a FRR 60 safer than a building with a FRR 30 and pressurisation? The absolute risk to life safety in the matrix cells is expected to different and they have not been designed to provide an equivalent level of safety for all occupants. Intuitively, it can been seen that occupants in a three storey sprinkler protected building would have a relatively higher level of life safety than occupants in a thirty storey sprinkler protected building irrespective of the other fire safety measures. Both buildings can be designed to be safe, but they may not have an equivalent level of risk to life safety. The reliability of fire safety measures is another important aspect that needs to be considered in a quantitative risk assessment. Previous sections in this report, contain reliability values for some of the fire safety measures. This data has been included to provide an indication of the reliability of the fire safety measures and their failure modes. Reliability data for some systems is available, but this is pretty limited and there is no correlations between the risk to life safety and the reliability of a system. For example a stair pressurisation system may work as designed, but fatalities could still occur. Some other difficult problems are questions such as, does a 60 minute FRR provide a higher level of safety than a 30 minute FRR and is a 30 minute fire rated wall more reliable than a 60 minute wall? Information on the reliability of a fire safety measure is not enough to determine the risk to life safety of the occupants. The reliability data needs to be assessed in conjunction with the ability of the fire safety measures to protect occupants to provide some sort of measure of effectiveness. The effectiveness of sprinklers and smoke detectors has been estimated