火灾工况下某特长城市地下道路疏散方案分析评估

Numerical Analysis of the Different Evacuation Strategy in Long Urban Underground Traffic Tunnel

为了评估某特长城市地下道路火灾工况下人员疏散的策略,借助计算流体动力学(computational fluid dynamics,CFD)模拟以及疏散模拟软件Building EXODUS对该城市地下道路设定的不同火灾疏散场景中可用的安全疏散时间与必需的安全疏散时间进行了模拟分析,并在此基础上对该城市地下道路的疏散方案进行了评估.研究结果表明:烟气自由扩散时,除隧道出口附近的疏散场景外,各疏散场景中可用的安全疏散时间都小于必需的安全疏散时间,导致部分人员的安全疏散受到威胁.因此,火灾发生时,必须及时启动烟气控制措施以保证内部人员的安全疏散.对于火灾发生在隧道出口的场景,在启动烟气控制系统保证火源上游人员安全疏散的同时,火源下游还应有一定的保障措施使下游车辆能快速驶出起火隧道.

Evacuation strategies under different fire scenarios in a long urban underground traffic tunnelwere evaluated by numerical methods in this paper. The available safety egress time under no ventilationcondition and the required safety egress time were obtained. The results show that the required safetyegress time in most scenarios are longer than the available safety egress time except in the scenarios wherethe fire happens near the tunnel exit portal. This might be dangerous for people who cannot evacuatesafely. The smoke control system must be run in time for assuring the safety evacuation of the people atthe upstream of the fire. For the scenarios near the exits of the tunnel, special measures should be takento make the cars at the downstream of the fire drive out instantly as the smoke ventilation system is inoperation.