doc-给排水专业毕业设计外文文献翻译-给排水

doc-给排水专业毕业设计外文文献翻译-给排水内容摘要：

ng. For example, if the sprinkler system fails the occupants will be protected with passive protection and smoke control systems. The following sections discuss the three building height limits with respect to the fire safety measures that have been remended. The staged evacuation strategy has not been discussed separately as it is a bination of the other two strategies and the same fundamental principles apply. Buildings greater than 25m in height. Once buildings exceed 25m in height, the ability of the fire brigade to rescue occupants externally bees limited. Therefore, a higher level of fire safety needs to be provided to the stairs and escape paths. Emergency lifts are also considered an option to provide rapid access for the fire brigade and egress for disabled occupants. As buildings bee taller the level of fire protection needs to increase. This is due to: ??Further travel distances, resulting in a higher chance of exposure to fire and fire products, and longer exposure time. ??The reduced ability of the fire brigade to rescue people externally ??The increased time for the fire brigade to reach upper levels ??More occupants, resulting in a higher risk of injury and deaths ??There is a greater variability in occupant abilities and human behaviour, due to the greater number of occupants ??There are more sources of ignition and fireEvacuation in buildings greater than 25m An evacuation strategy relies on the protection of egress paths, as well as the protection of occupants in their apartments before evacuation. The protection of egress paths is critical to ensure occupants are not evacuating through untenable conditions. In buildings greater than 25m high, egress distances can be consider able and therefore, the time occupants spend in escape paths can be significant. In a sprinkler protected building, protection is provided by: 1. The sprinkler system. The sprinklers will activate and extinguish or control the fire, reducing the threat to occupants. 2. Compartmentation and mechanical systems. Rooms, corridors and stair shafts are remended to have a FRR of at least 30 minutes. This will contain the fire in the room of origin and protect occupants before and during egress. Selfclosers provided on doors are to ensure the fire does not spread to the corridor. The stairs are to be pressurised to limit smoke spread, provide a partial safe egress paths and provide a smoke free area for the fire brigade. 3. The final level of protection is the fire brigade. The fire brigade’s role would be to assist any remaining occupants and extinguish the fire. A connection n to the fire brigade will be provided to achieve a faster response. In a nonsprinkler protected building the systems 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. An increased FRR to 60 minutes minimum. This is to provide additional time for occupant evacuation and fire brigade intervention. If occupants choose to stay in their apartments the i。