Study on the Feasibility of Downward Evacuation in a Metro Station when the Station Hall Catch Fire

摘要

As more and more deep-buried metro stations appear, it’s becoming more and more difficult for people in the station hall and on the platform to evacuate in an emergency in these deep-buried stations. If people in the station hall choose to evacuate to the outside when fire happens in a underground station hall, the spread direction of the smoke is in coincident with the evacuation direction, which is unfavorable for the evacuation as well as the rescue from outside. Is it possible to use the platform as a shelter when the station hall catch fire? In this paper, the numerical method was used to demonstrate the feasibility of downward evacuation under the condition that fire happens in the station hall. At first, safety evacuation criteria were made to judge the feasibility of evacuation. Then, numerical models were established by FDS software, the smoke movement, the temperature, the concentration of carbon monoxide, and the visibility were taken into consideration to demonstrate the feasibility of downward evacuation. Different locations, different heat release rate of fires in the station hall were also calculated and analyzed. Results show that the downward evacuation to the platform is feasible during a fire in the station hall under the condition that the smoke exhausting system in the station hall can work properly and has enough efficiency.