Study On The Influence Of Fire Source Location On Safe Evacuation In Underground Commercial Street

Along with economic development and the urban population growth, the buildings have to be forced to go to the ground in urban. At the same time to solve this problem, due to attribute of the building- "underground", fire risk of the buildings are also increased. In all kinds of underground buildings, the underground commercial street has a higher fire risk. Its characteristic has the large fire load, the difficult evacuation and the large power consumption, etc. In case of fire, it will cause severe casualties and losses. Therefore, to protect the person safety in fire, based on the structural feature of the underground commercial street, combined with the actual situation, it is very necessary to study the fire and evacuation.The research object is the underground commercial street in the paper. Based on comparison and analysis of internal and external research status and of fire evacuation research method, the fire dynamics simulation software PyroSim and evacuation simulation software Pathfinder are as the tool of computer simulation. First, calculation method of available safety egress time(ASET) and required safety egress time(RSET) are decided. Then according to the actual situation and the fire danger factors of the underground commercial street, fire and evacuation physical model is established. Secondly, the influence of flue gas and the critical time of CO concentration, temperature and visibility of every fire escape are get by fire simulation of "big model ", "small model ", the difference fire position. They are used to sum up the representative fire position and their ASET. Thirdly, evacuation is simulated and analyzed in every case of representative fire position, to getting RSET of fire escape. Finally, dangerous level of the fire position can be acquired by analyzing and comparing ASET and RSET. And suggestions are proposed.Through such of contrast analysis can have: on large underground commercial street fire evacuation research, you can used "small model" which is determined by the greatest effect scope of flue gas instead of "big model" constituted by the whole underground commercial street. The fire position is symmetric along the passageway in the underground commercial street where shop is symmetric along the passageway. Researching fire in other areas of the underground commercial street, ASET will be determined by CO concentration. Typical area of the underground commercial street has five representative fire position. And its fire dangerous level is decreasing gradually from the ends to the middle. By increasing the safety exit width and "evacuation waiting area" can satisfy evacuation requirements.