Simulation Research On Fire Safety Assessment Model And Fire Protection System Of CangShan Tunnel

In recent years,with the acceleration of highway construction,the construction of highway tunnels also have increased rapidly.As a special type of building,the main tunnel project of highway tunnels would be damaged once the fire occurred,and caused great difficult to escape.Due to the closed environment of tunnels,the large traffic volume,and the densely populated personnel,escaping and rescuing are very difficult work.If the fire cannot be promptly handled,it will cause double loss of personnel and property,at the same time,there is a bad social impact.Therefore,it is very important to study and discuss the weak link in the fire safety of the tunnels.This thesis is based on the Bayesian network fire safety assessment model,combined with AHP to determine index weight,and makes an overall assessment of the fire safety situation of highway tunnel.Taking the CangShan Tunnel as the background,we verified the rationality of the evaluation model and obtained the following research results.(1)Through constructing the Bayesian network to analyze the model of highway tunnel fires,and using AHP to evaluate and calculate,I concluded that the comprehensive score of the safety of highway tunnel is 58.25,indicating that the fires in highway tunnels are in a three-level safety state.Fire safety conditions and risks are in a general risk.(2)The evaluation found that the overall scores of fire safety facilities and evacuation facilities in the tunnel are low.This shows that,on the one hand,the supporting and good use of the fire safety facilities in the tunnel have a great influence on the safety of the tunnel fire.On the other hand,the setting of standards and using of evacuation facilities are essential for evacuation and escape after the fire in the tunnels.(3)As the background of the Cangshan Tunnel,Using the FDS fire numerical simulation software,the thesis verified the smoke extraction facilities in the fire safety facilities in the tunnel.Through the numerical analysis of the influence of temperature distribution,the smoke flow and the visibility after the fire in the Cangshan Tunnel,I concluded that the supporting and good use of the fire safety facilities in the tunnel has a great impact on the fire safety of the Cangshan Tunnel.(4)With the background of the Cangshan Tunnel,and through the establishment of evacuation model,simulate the evacuation time in ordered and disordered condition,then compared them.We can conclude that the set of standard and well run facilities are crucial for the safe evacuation of Cangshan Tunnel.