基于蒙特卡洛法的城市隧道火灾概率分布研究

The Probability Distribution of Urban Tunnel Fire Based on Monte Carlo Method

城市隧道交通呈现出常发性、周期性交通拥堵/阻塞,朝夕现象明显,交通流量大、人员基数多,交通合流、分流交织区段复杂等特点,其交通环境的封闭性又与普通道路不同,火灾场景的发生概率与非城市隧道有较大区别,火灾后果严重。采用理论计算、公式推导、交通调查、随机抽样模拟等方法,对城市隧道火灾概率分布进行研究,利用MATLAB实现了百万次不同工况火灾场景数值模拟,得到了两车道隧道25 MW燃烧规模引燃场景的发生概率在15%以上,三车道隧道25 MW燃烧规模的引燃火灾场景发生概率在20%左右。从火灾发生概率和燃烧规模两方面考虑,5 MW、20 MW、25 MW、30 MW、40 MW、60 MW的发生概率较高。研究成果可为实际工程疏散安全设计参数提供依据。

Urban tunnel traffic has many traffic characteristics,such as frequently periodically traffic congestion/blocking,obvious tidal phenomenon,a large traffic flow,a big population of people,complicated traffic confluence and cross-flowing intertwined sections.Unlike ordinary roads,the probability of fire scene is quite different and the consequences of a fire are extremely serious.The theoretical calculation,formula derivation,traffic survey,random sampling simulation and other methods are adopted to study the probability distribution of urban tunnel fire.MATLAB was used to realize the numerical simulation of a million fire scenarios under different working conditions,and the results showed that the occurrence probability of the 25 MW combustion scale ignition scenario of the two-lane tunnel was more than 15%,and the occurrence probability of the 25 MW combustion scale ignition fire scenario of the threelane tunnel was about 20%.Considering the probability of fire occurrence and combustion scale,the probability of5 MW,20 MW,25 MW,30 MW,40 MW and 60 MW are relatively high.The research results can provide a basis for the design parameters of evacuation safety in practical engineering.