Study On Smoke Flow And Personnel Evacuation Simulation In Subway Tunnel Fire

The subway tunnel fire is a disastrous phenomenon which contains the process of burning, turbulent motion and thermal transmission. The smoke in the fire is the greatest factor which threatens people's lives.The statistics of departed fire cases indicate that more than 85% people died in subway tunnel fire due to inhaling the toxic gases. Therefore, it is very important and meaningful for the fire fighting system design and safety operation management of the subway system to research on the smoke control and personnel evacuation in subway tunnel fire.On the basis of comprehensive analyzing the research of subway tunnel fire and personnel evacuation at home and abroad, the flow feature of smoke in different slope tunnels under the condition of natural ventilation and the effect of slope on the critical velocity were studied by FDS. The characteristics of smoke spread and the distribution discipline of temperature in subway tunnel fire adopting semi-transverse ventilation system were also researched through numerical simulation, and different ways of ventilation system were compared. The results indicate that the slope of tunnel has certain effect on the flow of smoke and the critical velocity, and the influence is diverse from each other in the tunnels of upgrade and downgrade. Semi-transverse ventilation system is better than natural ventilation system and longitudinal ventilation system.Through questionnaire surveys to the passengers of rail transit in Chongqing, the passengers'personal parameters and the response characteristics to fire were obtained. The relationship between passengers'characteristics and behaviors was analyzed by contingency table, and the results show that sex and the experience of fire escape training or fire safety education have prominent effect on whether to notice the extinguishers and know the safety devices well in the train. Age has certain effect on the reactions when it is very crowded during the evacuation. Educational level and the experience of fire escape training or fire safety education have great effect on the first reactions in the fire.The ZGESS(Zone Grid Evacuation Simulation Software) was improved by adding two buttons which are "cancel" and "revert" on the using interface and modifying the evacuation velocity model to highlight the bottleneck during the process of evacuation. The evacuation simulation in subway tunnel fire was done by the improved program, and three ways of personnel evacuation were compared. The results show that in the subway tunnel adopting semi-transverse ventilation, doing two-way evacuation along the evacuation platform can reduce evacuation time and improve the efficiency of evacuation when adopting the way which combining the lateral evacuation platform and the contact passage.