Study On Fire And Safety Evacuation Simulation Of A Beijing Subway Station

The overall subway system is lower than the ground,with poor ventilation,slow cooling,low visibility and so on features,and it belongs to the public gathering places with a larger population density,which has a certain degree of difficulty for the evacuation and rescue.Because of its large volume,high speed,small pollution and little noise advantages,subway is favored by people,and it has played a crucial role to ease the congestion of ground traffic.With more and more people take the subway,accompanied by the incident is that the consequences become more serious once the subway accident occur.And if there is an accident,it easily leads to greater casualties.The fire is the most in the subway accidents.The reasons are that subway fire is difficult to prevent,because of its relatively strong sudden,and subway station belongs to underground construction,with the complex building structure,relatively closed space,relatively limited imports and exports,and a dense,greater fluidity,chaotic structure staff,which easily leads to a large number of casualties.Seats,corridors and billboards,etc.of the subway station,are flammable or combustible materials,which help the fire burm,and fire burning gas and other toxic gases not only hinder people's attention,but also the high temperature and smoke of combustion will cause a greater psychological panic,which easily lead to malignant events of the death of the group,and secondary accident.Do a good evacuation can greatly reduce casualties and the severity of the consequences of the accident.Therefore,the study of the subway fire and evacuation is indispensable and helpful to provide a theoretical basis for the evacuation of personnel after the accident occurring.Because from the fire began to spread to it can not let people escape,in the middle there are some time,if it can be completed during this period of personnel evacuation,then it can ensure the safety of life,reduce the severity of the consequences of the accident.This paper is based on the above reasons,taking a double-layer island subway station in Beijing as the research object,through observation and measurement,using Pyrosim software to build subway station model,and set fire type,fire source location,observation points and so on.The FDS software was used to establish the fire simulation model to simulate the fire occurrence process.The available evacuation time was determined by observing the flue gas spreading rate,smoke layer height,flue gas temperature and visibility of each observation point.Then the safe evacuation time required to complete the evacuation was simulated by EVACNET.Compared the available evacuation time to the safe evacuation time,to determine whether the evacuation of personnel can complete before reaching the fire hazard critical point.Analyze the reasons of the position can not complete the evacuation and make recommendations.