Smoke Characteristics And Passenger Evacuation Strategy On Fire In Metro Tunnel

With the rapid development of economy in our country,the congestion of urban traffic is becoming more and more serious.Due to large capacity,subway has been being built in more cities as main transport systems.Metro construction and operations have entered a new stage of comprehensive development in our country.Concentrated passenger flow and high crowd density in trains and stations make it difficult to evacuate passengers in case of emergency.When passengers start to evacuate in a tunnel fire,the narrow space can easily lead to stampede and other collateral accidents.How to ensure the safety of passengers in the tunnel and accomplish evacuation tasks quickly is a key issue worth studying deeply in a full scale.When there is a fire in a tunnel,the smoke generated from the fire source can directly affect the physical and psychological characteristics of passengers.Many factors can influence gas diffusion,such as tunnel geometry,fire characteristics,ventilation conditions and so on.The evacuation plan is largely related to the configuration of facilities in subway tunnel.In addition,ventilation control and personnel organization will also affect the efficiency of evacuation.Based on the research results at home and abroad,this dissertation simulates the smoke characteristics in metro tunnels,builds a simulation platform for the evacuation of passengers through smoke,and compares the ventilation and evacuation plans in different conditions.The main contents of this dissertation are as follows:(1)Using fluid dynamics simulation to analyze the characteristics of fire smoke in metro tunnels,research on the tunnel geometry influence,fire source characteristics and ventilation conditions on smoke diffusion is carried out to identify the tunnel safety range in different conditions.(2)The evacuation simulation platforam in metro tunnel is built based on the social force model,and then fire smoke data is loaded into the platform.The passenger evacuation process in the tunnel is simulated with the influence of smoke on passenger movement characteristics taken into consideration.(3)The dissertation analyzes the factors which may influence the evacuation efficiency,and then compare passenger distribution and evacuation efficiency in different scenarios for the optimal allocation of tunnel facilities and evacuation organization plan.(4)The simulation platform is used to reflect the evacuation process in different fire locations.Comparing the evacuation efficiency and safety indexes of different schemes,the safe and efficient ventilation and evacuation plan can be generated.