Study On Fire Evacuation Of Urban Underground Traffic Tunnel

With the rapid development of transportation in our country,large tunnels are increasingly being built,and a huge number of tunnel fire accidents also have emerged,which has brought great challenges to the safety of the tunnel.The dangerous parameters in the fire and the evacuation of personnel have also become scholars at home and abroad.research focus.This article uses the combination of FDS and Pathfinder software to establish urban highway tunnel fire model and evacuation model respectively,starting from two aspects of the tunnel internal structure and evacuation characteristics,to conduct a numerical simulation study on the fire and evacuation of urban underground traffic tunnels.The simulation results were combined and analyzed to determine the available safe evacuation time in different fire scenarios,and the effects of evacuation channel spacing,casualty ratio,team evacuation ratio,and elderly ratio on evacuation were obtained.The main research contents and results are as follows:(1)Summarize the causes and characteristics of road tunnel fires,the behavior and psychological characteristics of personnel evacuation in fires,from the three stages of fire development and the two times of personnel evacuation to illustrate the safety guidelines for personnel evacuation in fires.(2)A tunnel evacuation model was established,and different evacuation scenarios were set from two angles of personnel characteristics and tunnel tunnel geometry,and the necessary evacuation time for different evacuation scenarios was obtained.And specifically analyzed the evacuation channel spacing of different tunnels(60m,80 m,100m,120 m,140m,160 m,180m),the proportion of different casualties(0%-40%),the evacuation ratio of different teams(0%-80%),The changing rules of the necessary safety evacuation time under different proportions of elderly people(10%-70%),it is concluded that under the two circumstances of considering the phenomenon of casualties,the tunnels of different lengths(200m,600 m,1000m,1400 m,1800m,2200 m,2600m)the best evacuation channel spacing.Combined with the results of the fire simulation study,the evacuation optimization suggestions are put forward.(3)The flue gas temperature,CO concentration,visibility and O2 concentration under different fire source powers(5MW,20 MW,50MW)and different ventilation conditions(natural ventilation,critical wind speed)are analyzed,and the available safety of each scene is obtained Evacuation time.(4)Analyze the necessary safety evacuation time under different guidance methods in the 200 m tunnel,and import the smoke results of the fire simulation into the tunnel evacuation model,get the death situation and specific causes in each scene,give the evacuation optimization plan and verify the feasibility.