长大公路隧道火灾安全疏散性能化设计与分析

基于性能化防火设计方法,分析火灾条件下长大公路隧道内人员疏散行为的特点,给出隧道内人员疏散的安全判据,并结合某隧道的结构及车流特征对人员疏散过程进行了数值模拟研究,分析隧道在正常通车和局部行车堵塞时,不同火源位置、横通道间距与横通道宽度对人员疏散时间及安全状态的影响。结果表明,与建筑内人员疏散不同,长大公路隧道内火灾的可用安全疏散时间(ASET)与需要的安全疏散时间(RSET)均为沿隧道长度方向位置的函数。隧道内人员安全疏散的时间曲线在各横通道疏散口出现峰值,这主要是受到横通道通行能力的限制,各疏散口人员集聚等待所致。当隧道发生局部堵塞时,横通道口需要的安全疏散时间显著增加,危险性也急剧增大。隧道内人员疏散的性能化防火设计应综合考虑火源位置对人员载荷及疏散口位置可用安全疏散时间的影响。该研究为公路隧道火灾安全疏散设施的优化设计提供依据。

Performance based Fire Protection Designs and Analyses for Occupant Evacuations in Super long Road Tunnels

In this paper, the evacuation characteristics of occupants in super long road tunnels in the case of fires were analyzed and the corresponding safety criteria for evacuations were given. Numerical simulation studies were conducted on the evacuation of occupants under conditions of normal traffics and local jams respectively in a tunnel by taking its structure and the vehicles flows into consideration. Influences of various fire locations, spacing between and widths of transverse passageways were considered. Results show that the available and the required safe evacuation time(ASET and RSET, respectively) are both functions of positions in the longitudinal direction of the tunnel, which is different from the case in building evacuations. Peaks occur on the time curves of occupant evacuations at the gate of each transverse passageway, which is mainly caused by the aggregating and waiting behaviors at each gate. When a local traffic jam occurs, the RSET for the region near the gate of transverse passageways is dramatically enhanced, the same are the hazards. And the performance based fire protection designs for occupant evacuations in super long tunnels should consider the influences of fire source locations on occupant loads and the ASET at evacuation gates comprehensively. The investigation for the performance based fire protection designs for the occupant evacuations in super long road tunnels could provide the valuable references for the optimization designing of the safety evacuation establishments for the road tunnels.