Performance-based Fire Protection Design Of Urban Traffic Link Tunnel

In recent years,with the rapid development of urbanization,the urban ground becomes more and more shortage,so the city road network was transferred to the ground.This thesis try to build urban traffic link tunnel to ease the city ground traffic congestion and beautify the urban environment.The urban traffic link tunnel has many characteristic,such as high safety grade,complicated structure,and high danger of fire disaster.The important issues that we are faced with are reasonable and effective fire protection and smoke control design.Based on the typical fire scenario numerical simulation,this thesis gets the detailed state of the smoke,and provide a theoretical basis for personnel safety evacuation.First,this thesis carries out an entity ventilation test and numerical simulation on a Zhengzhou tunnel which was in use.Through the analysis of tunnel structure fire protection design,tunnel electric fire protection design,tunnel fire automatic alarm system design,this paper provide theoretical basis for the urban traffic link tunnel.Second,use the FDS numerical simulation of the typical fire scenario,through the analysis of the spread of gas and smoke extraction of different fire state.The thesis can conclude that: half the horizontal linkage mechanical smoke extraction mode can effectively control the fire gas,the vertical mechanical smoke extraction modes can effectively control long ramp fire smoke.Lastly,according to the temperature distribution and the visibility state of different fire scenario,can get the risk time of each evacuation exit.According to the calculation formula of the evacuation time,this thesis can get the time of the farthest point in the scene reach the safety evacuation.By the concept of evacuation,comparing the above two kinds of time,this thesis can provide theoretical basis to the evacuation plan and the establishment of safety evacuation path.