Research On Performance-based Fire Protection Applicated In Underground Tunnel Constructions

Nowadays, traffic is the major rub that most of cities met with in spreading. And developing public traffic is the main means for solving the problem. According to developed countries' experience, underground is the essential measure to solve the problem of public traffic in cities.Because the great mass of underground is deeply belowground, enwrapped by rock and soil, there is fewer channels connecting with outside and channels is confined. The underground fire will spread and cause serious economy loss and casualty of human beings. So studying on the happening and developing rule of tunnel fire to reinforce the fire safety design is of great importance.According to Chinese code of design for underground fire safety, in the tunnel hydrant and chemistry fire extinguisher are the main fire safety facilities at present. So in most fire cases the inside hydrant is useless. Over here we advise adopt sprinkler systems, the most advantage is that sprinkler systems can automatically act to extinguish the early fire.This paper has investigated adequately on the existing technic protecting the underground fire in the world. On the basis of investigation and the code and standard of performance-based fire protection design, this paper puts forward the whole design scheme with regard to the underground tunnels. The main achievements and conclusions are as follows:1. The 85% of personel casualty in fire is caused by smoke, so design of ventilation system is of great importance. This paper validates the validity of half transverse ventilation system using FDS, and analyses the development rule of temperature field and smoke distribution in tunnels with half transverse ventilation system. The result proves that half transverse ventilation system can control the smoke refluence phenomena and depress the temperature, creating a nicer environment for evacuation.2. This paper advises adopt sprinkler systems in underground tunnels. Then I adopt the application software FDS programmed by NIST to simulate a supposed underground tunnel fire. This paper simulate two cases that setting sprinkler systems in tunnel or not. From the analytical outcomes of temperature field, soot distribution, the speed field of gases and the CO concentration, I can conclude that setting sprinkler systems in underground tunnel is feasible.3. This paper analyses the economics of setting sprinkler systems in underground tunnel with the view of economy of fire protection, for unification of safety and economics of underground tunnel fire protection system.4. This paper applies the softwear S G Evacuation Model to simulate the safeevacuation of the underground interzone tunnel.