Study On Fire Evacuation And Rescue For Single-Tunnel Subtended Traffic In Ba Langshan High Altitude Road Tunnel

With the rapid rise in the west, especially in Sichuan-Tibet highway and Sichuan-Tibet railway construction, there are more and more high-altitude extra-long tunnel. Among them, Que Ershan highway tunnel altitude is4300meters, and Feng Huoshan railway tunnel has reached4905meters high. However, if a disaster under high altitude, people’s ability to escape is decreased obviously. At present, Domestic and international highway tunnel design specification only meet disaster relief needs of tunnel below3000meters altitude. Study on disaster prevention and rescue technology of tunnel above3000meters altitude is little, and there are no available mature fruits.In this paper, it research on the operation safety technology in the tunnel fire, regarding Ba Langshan high altitude highway tunnel as the research object, based on the attenuation law between human movement endurance and altitude, relying on fire smoke diffusion characteristics of high altitude tunnel. The main contents and conclusion can be listed as follows:(1) Combining with domestic and international research results on fire characteristics research in high-altitude low pressure and low oxygen environment, using CFD software to establish a suitable high altitude fire model, it study on fire characteristics about heat release rate, smoke concentration, smoke diffusion velocity, temperature development, smoke flow patterns and so on.(2) Through theoretical analysis, data sorting and field experiment, the law between human movement endurance and altitude has been studied. Studies have shown that VO2max which has a certain relationship with altitude can be used as an indicator to measure the endurance of human movement. Finally, the escape velocity formula was derived.(3) Considering the smoke layer height, radiant heat, convective heat, toxicity and visibility, we determine the judging criteria for ASET. Combining with research results on fire alarm time, response time and evacuation speed, we get different categories staff evacuation speed in smoke state and smoke-free state.(4) The results of fire evacuation simulation for background project, have shown that medium scale fire high temperature smoke will be controlled within a certain range by0.5m/s opposite direction wind in the evacuation stage. It is suggested that the pedestrian cross channel spacing decrease to150m under30MW fire scale.(5) The relationship between critical wind speed and altitude in the fighting stage has been studied. Studies have shown that there is no obvious relationship between elevation influence coefficient and Different fire scale. We establish the formula of critical wind speed considering altitude factors.Above all the research, high altitude environment have significantly effect on the combustion characteristic and body function, and it is a challenge to design, safety operation and norm-setting of high altitude tunnel. The study on establishment of the rescue system need go on.