Research On Fire Evacuation Route Of Two-story Island Structure Subway Station Based On CA And SFM Model

With the continuous development of urban rail transit,the role of subways in today’s society is becoming more and more obvious.With the continuous expansion of the construction scale and number of subway stations,the probability and danger of fires also increase.Although the facilities and materials in subway stations are mostly non-combustible and flame-retardant materials,according to historical statistics,fire is still one of the most serious threats to subway stations,and smoke is the main reason for threatening the evacuation of people.In order to study the evacuation of people in the case of fire in a typical underground double-deck island subway station,a domestic double-deck island subway station is taken as an example.First,the fire field experiment was carried out,and the fire simulation simulation was used for proofreading.Then,the cellular automata model and the social force model are coupled,and the relationship between people’s self-driving force,people and people,and people and the surrounding environment is considered,the accumulation phenomenon in the process of personnel evacuation is analyzed,and the personnel evacuation route is obtained and the remaining population graph.Finally,the law of smoke diffusion is coupled with the evacuation of people.According to the coupling results,planning and suggestions for the subway station plane and optimization of the evacuation route are proposed.The main research contents and results are as follows:1.Theoretical analysis of the subway station fire is carried out,the heat and mass transfer phenomenon of the flue gas in the process of diffusion is analyzed,the smoke and gas diffusion model of the subway fire is summarized and analyzed,and the evacuation model of the subway fire personnel is classified and summarized,which can be used for the follow-up subway.The analysis of the station smoke diffusion law and the selection of the personnel evacuation model provide theoretical guidance.2.Through the fire field experiment,the smoke settling time and temperature change laws were analyzed,and the smoke diffusion laws were obtained,which laid the foundation for the construction of the subsequent subway fire proportional model.The results show that the spread of fire smoke in the subway station is greatly affected by the main structure and the supply and exhaust air.The asymmetry of the number of entrances and exits in the station hall causes the smoke to spread asymmetrically.The smoke settlement area of the station is mainly concentrated at the right end of the platform.3.The fire model of the subway station is constructed,and the experimental results are used for proofreading.The smoke diffusion law of the subway fire model is basically consistent with the experiment,and a more intuitive smoke cloud map with a height of 2m is extracted according to the minimum clear height.It is found that at this height,the flue gas in the station hall is mainly distributed in the central area of the station hall,and the temperature and concentration of the flue gas are high;the flue gas on the platform is clearly divided,and it is mainly concentrated at the right end of the platform.The temperature gradually increases.The results can lay a foundation for the coupling of subsequent subway fire smoke distribution and personnel evacuation.4.The self-driving force of people,the factors between people and people,and people and the surrounding environment in the social force model are added to the cellular automata model,and the personnel evacuation route and the curve of the remaining number of people are obtained through the coupled personnel evacuation model.The subway station gates and stair entrances have varying degrees of congestion and some unused situations,and people need to be diverted and guided in this area.5.By coupling the simulation situation of personnel evacuation with the diffusion law of subway fire smoke,the influence of subway fire on personnel evacuation was studied,the group characteristics of the evacuation process were analyzed,and the optimal evacuation route was proposed.Suggestions for planning such as load-bearing columns.