Simulation Analysis Of Subway Tunnel Fire And Evacuation

With the continuous expansion of China’s urban scale and the urban population increasing year by year,the subway has become the best way to solve the urban traffic problem effectively and it is known as the flow of the city.But the subway tunnel is located in the underground space,closed,narrow track safety evacuation platform,hidden dangers of ballast bed.once a fire,the rapid spread of smoke,fire,and complex layout of the tunnel pipeline pose a threat to the evacuation of the passengers in the train.How to ensure that people’s lives are not threatened,the property does not suffer losses,has become a matter of concern.Therefore,it is of great significance to study and analyze the characteristics of subway tunnel fire and the characteristics of subway fire emergency evacuation and put forward a reasonable and effective safety measures and evacuation plan.Taking a subway tunnel as the research object,the paper analyzes the Influence of potential safety hazards of ballast bed and evacuation platform,fire characteristics and personnel characteristics of tunnel on emergency evacuation.According to the domestic and foreign research methods of subway tunnel fire and evacuation,determine the fire simulation software Pyrosim and evacuation simulation software Pathfinder as the tool of computer simulation,and according to the essential information of subway tunnel and train,tunnel fire model and evacuation model are established.First of all,in the tunnel fire model,installing separately temperature,oxygen content,CO concentration and visibility detectors in ballast and evacuation platform to analyze the changes of two environmental temperature,oxygen volume fraction,CO mass concentration and visibility.With the increase of time,we can find out the dangerous range of the fire parameters in two and the time to reach the dangerous state and comparative analysis of two fire parameters.Some results are obtained.Under the condition of no ventilation: fire parameters at different times will pose a threat to the staff and Centered on fire;Low oxygen content and CO threat to personnel mainly concentrate in the train head and rear compartment;the temperature can rise to a threat to the entire train crew;visibility can rise to a threat to the entire tunnel;the temperature and visibility at the two ends of the train are all earlier than the others;the visibility of ballast reaches the dangerous state time less than the time of evacuation platform;1200s,the visibility of ballast is more than evacuation platform visibility.It is recommended to increase security measures at both ends of the train,such as increasing lighting,enhancing the intensity of the evacuation signs,and doing a good job of evacuation guidance,and so on.Secondly,in evacuation model,the personnel are divided into six categories and simulation analysis of the nine evacuation plans.The analysis found that the plan of Evacuation platform+ ballast+ End doors is optimal.When a fire broke out in the middle of the train,Personnel should be evacuated from both ends of the train that is end doors and 1~2 side doors.Avoid a large number of evacuation from the evacuation platform and the personnel near the fire should do Priority evacuation.It is suggested that the coordination evacuees should be set up and have the function of traffic lights during evacuation.Finally,according to the conditions of safe evacuation,the paper puts out the selection of the best evacuation plan should be based on the tunnel ventilation conditions.To increase the tunnel fire ventilation measures,improve the optimal evacuation plan.When no wind in tunnel,should enable evacuate to safe area as soon as possible.When the tunnel ventilation,it is necessary to ensure passengers are windward evacuation before the tunnel fire smoke threat evacuation.