城市地下商业街火灾中逃生模型的分析

Analysis of Flees for Life Model during a Fire in Underground Business Street

分析了地下商业街火灾时火灾临界危险条件和人员的疏散特点,提出了地下商业街火灾中人员安全疏散模型,确定了人员安全疏散时间的计算方法。以某地下商业街为例,计算了人员安全疏散所需要的时间,找出了人员能安全疏散的临界密度。研究与计算结果表明:该商业街火灾时,人员密度达到0.5人/m2后,楼梯口及楼梯间出现堵塞现象,人员开始出现混乱;同时,人员疏散至安全地带的楼梯总宽度是整个疏散过程的瓶颈,人员通过楼梯的时间占总疏散时间的80%以上,而楼梯的疏散能力主要受人员流量和楼梯的有效宽度所制约。基于计算结果,提出了相应的解决方法和措施。

The critical conditions and characteristics of evacuation from underground business street under fire were analyzed. An evacuating model was designed and a primary method for calculating the safe evacuation time was presented. With one business street as an example, the necessary safe evacuation time was obtained and the critical density of the safe evacuation was found. The results show that there will be an jam at the stairs entrances and along the stairs when the population density reaches 0.5 people per square meter, where people become in disorder; mean- while, the width of the staircase from the evacuation corridor to the safety room would be the bottleneck in the evacuation procedure and the time passing it takes more than 80% of the total evacuation time. The evacuation ability of stairs mainly is subjected to the personnel＇s flows and the valid width of stairs. According to the calculation results, the methods and measures were presented for this case.