火灾情况下某单洞双层盾构隧道人员疏散分析

Evacuation analysis for the tunnel fire in the single underwater cavern with double-layer shield

对于火灾情况下单洞双层超大断面双层盾构隧道人员疏散问题,在现有的规范中,没有相关条文说明给出明确要求。主要针对火灾情况下某单洞双层盾构隧道人员疏散进行分析,对我国某水下盾构隧道开展了火灾情况下人员疏散的模拟研究。利用Pathfinder模拟疏散软件,通过模拟计算获得该双层盾构隧道发生一起火灾情况下人员逃生所需的时间,验证其疏散通道的疏散能力,以及疏散楼梯尺寸、疏散逃生洞口间距的有效性。在模拟中,将火源设置在隧道的下层,人员从隧道下层往上层疏散。结果表明,基于隧道内疏散楼梯最大的有效宽度,当疏散逃生洞口间距设置为36m时,方可将人员疏散至未失火层隧道的时间控制在6 min以内,从而满足"6 min原则"要求。

This paper intends to make an investigation for the evacuation of underwater single cavern with double layers shield tunnel fire. As is known,tunnel fire,as one of the typical topics in fire disaster research,attracts more and more attention for its catastrophic consequence due to its occurrence in a particularly long-narrow structure space. In this paper,we have chosen to adopt a software named Pathfinder as a simulation tool to make a numerical simulation analysis for different types of safety exits in the fire-disaster zones. Taking all the different typical fire conditions into account,we have done a numerical simulation,showing the safe evacuation time in case of an underwater shield tunnel fire. We have also obtained the required time for evacuation of the double layers shield tunnel in hoping to test the capacity of evacuation passageway, the effectiveness of evacuation stairs width and the evacuation exits distance. In such a case,the fire is supposed to occur in the lower layers of the tunnel,whereas the human escape can be made available from the lower layer to the upper layer. Based on the width of the tunnel being largest possible evacuation stairs,the evacuation time can be controlled in 6min to meet the＂6 min principle＂demands on the condition that the evacuation exit distance is supposed to be 36 m long. However,the distances of 54 m and 72 m long evacuation exits are not enough to be supposed effective. On the other hand,the evacuation stairs should be made broad enough to create a better evacuation environment. Furthermore, it is also necessary to be equipped with well-enough evacuation lighting and evacuation instructions to lead the human workforce to the exits for evacuation and prevent from likely-to-be psychological panics. What is more,this paper has also provided corresponding emergency evacuation tactics and strategy for dealing with the underwater double layers shield tunnel fire,all of which can help to provide a valuable reference to the personnel evacuation design in case of such tunnel fires.