Research On The Fire Evacuation In Long-tunnel-intervels Of Urban Rail Transit

Security is a permanent theme in the development of urban rail transit system.When speaking of fire evacuation in subway system,although there are a lot of relevant research at home and abroad,but most researches are focused on the evacuation in subway station,and less for evacuation in tunnels.As to long-tunnel-interval where there could be three subway train at the same time during operating period,due to the lack of engineering precedent,researches are rarer.With the increase construction of new subway line and difficult area found in construction,more and more long-tunnel-intervals are likely to appear.In this case,this paper focus on solve the fire evacuation problem of subway long-tunnel-interval.According to two real-existing long-tunnel-interval of Beijing M17 line,this paper is based on the randomness of evacuation.By combining the evacuation model of extreme distribution and fire numerical simulation software-FDS,this paper sets up survival probability model for the slowest in long-tunnel-interval fire cases.This paper is divided into the following several parts:(1)The causes,characteristics and measures of rescue and evacuation in subway long-tunnel-interval fire are researched,then this paper summarizes the domestic and foreign relevant standards and literature on the existing research of tunnel fire.(2)The method of separating three subway trains in long-tunnel-interval by the interval wind well are put forward.The most disadvantageous train position in fire condition when there are three subway trains in the tunnel at the same time are studied.Then this paper makes a detailed analysis about ventilation and evacuation plan for the most disadvantageous train.(3)Numerical model of fire by FDS to figure out the necessary evacuation time in different condition are established.This paper researches on the whole evacuation based on the randomness of people,dividing evacuation into three periods.Focusing on the lowest people's whole evacuation time by using the GEV and Gumble extreme value distribution of evacuation time and evacuation speed,the whole evacuation time samples are gotten by using the monte-carlo algorithm.Last this paper compares this two kind of time according to Safety evacuation rules,setting up survival probability model for the slowest in long-tunnel-interval fire cases.(4)According to two real-existing long-tunnel-interval of Beijing M17 line,this paper uses the method in(2)to calculate the position of interval wind well.the sample of necessary evacuation time is gotten by using Matlab to realize the monte-carlo algorithm in(3).Then this paper designs a variety of different conditions of fire experiment,uses FDS to get the available safe time.Last,this paper uses statistical analysis technique to study necessary evacuation time and available safe time,researches the influence of connecting passage space on survival probability of the slowest that in the nearest car to fire,gets the most reasonable connecting passage space and width.This paper are accorded to two real-existing long-tunnel-interval of Beijing M17 line,researching long-tunnel-interval where there could be there subway trains at the same time.This kind of researches are rare,which is the 1st innovation point.Using the monte-carlo algorithm and the extreme value distribution of evacuation time and evacuation speed to set up survival probability model for the slowest,which transplants the extreme value distribution theory in finance,weather,environment and information into evacuation.That is the 2nd innovation point.The conclusion of this paper can provide the basis for the future safety design of metro tunnel.