“T”型地铁换乘站多点火灾工况下综合火灾危险性研究

为探究大型地铁站多线路火灾场景中的综合危险性，采用火灾动力学软件FDS构建“T”型换乘站全尺寸模型，对不同火源位置、不同火源功率以及是否开启地铁排烟风机等12组工况进行数值模拟；采用性能化方法确定可用疏散时间，并通过综合火灾风险评估方法计算各工况总安全指数。结果表明:1号线站厅层和2号线站台层双点火灾为最不利火灾场景；1号线站台层和2号线站厅层双点火灾为相对安全火灾场景；火源功率的增大会增加地铁火灾危险性，但不同火源位置工况中的安全指数变化趋势相似；排烟模式开启前，1号线站厅层火灾会导致较大的火灾危险性；排烟模式开启后，地铁总安全指数显著上升且安全指数变化趋势改变，此时2号线站台层火灾会导致较大的火灾危险性。

Study on comprehensive fire risk under multi source fire conditions in T type interchange subway station

In order to study the comprehensive risk of multi line fire in the large scale subway stations,a full scale model of T type interchange station was established by FDS,and the numerical simulation under 12 groups of conditions with different fire source locations,heat release rates (HRRs) and ventilation modes was carried out.The available safe egress time (ASET) was monitored by performance based method,and the total safety index of each condition was calculated through the comprehensive fire risk assessment method.The results showed that the double source fire at station hall layer of Line 1 and platform layer of Line 2 was the worst fire scenario,while the double source fire at platform layer of Line 1 and station hall layer of Line 2 was the relatively safe fire scenario.The increase of HRR would increase the risk of subway fire,but the variation trends of safety index under different fire source locations were similar.Before activating the smoke exhaust mode,the fire at the station hall layer of Line 1 would cause larger fire risk.After activating the smoke exhaust mode,the total safety index increased significantly,and the variation trends of safety index changed.At this time,the fire at the platform layer of Line 2 would cause larger fire risk.