Research On Fire Emergency Evacuation And Obstacle Layout Of Public Buildings

Statistics show that the number of fire incident demonstrates an explosive increase in recent years,and the consequences of building fires,especially public building fires,are particularly serious.College library,with higher fire load and more combustible material compared to other buildings,is typical enough that a fire broke out in it would trigger a serious chain reaction to campus and pose threat to the campus.However,current research articles mainly focus on the evaluation of building’s fire protection performance,construction design optimization,and the optimization of evacuation route while there is relatively less research on the relationship between the obstacle’s layout of public buildings and fire emergency evacuation.There are problems in current research such as rough modeling of the building environment,the ignorance of the evacuation preference and cognitive level of the building users themselves and the lack of generalizability of the conclusions.Based on the above background,taking the typical public building college that library for example,this article aims to study the influence of obstacle layout on fire emergency evacuation for public buildings,exploring the obstacle layout that is most conducive to evacuation and proposing layout optimization and fire emergency management suggestions.The main work of this article is as follows:(1)The influence factors of fire emergency evacuation for public buildings were summarized through literature review method,based on the factors,a survey questionnaire was designed and distributed to college students and teachers nationally to understand the overall evacuation preference and cognitive level of college students to fire evacuation in library.And this paper concluded four crucial effect factors of college library fire evacuation that space change,escape signs,emotion contagion,and counter flow behavior.Through field research and the query of network data,the spatial distribution of obstacles in buildings,the main layout forms and parameters of obstacles,and the materials of obstacles were statistically analyzed to summarize the widely used and most representative spatial distribution,layout forms as well as characteristics of obstacles in college library.(2)Taking a college library that meets this characteristic as the basic model,a library BIM(Building Information Modeling)model was established for subsequent analog simulation.Then an actual field survey was adopted to determine the simulation parameters that the number of evacuation occupants and fire environment including the location of the ignition,the cause of fire,and the mode of fire growth.(3)Importing university library BIM model into Pathfinder software,and several experiments were carried out based on the Agent model to study the relationship between obstacle’s layout and fire emergency evacuation of college library from shallow to deep.The impact of obstacles on fire evacuation was explored through setting up two experiments,evacuation with and without obstacles.This article proved that the obstacle could prolong the evacuation time by 30.77% than before on the floor where the fire is located and 25.96% for total evacuation time.By analyzing the simulation processes of evacuation under different obstacle layouts,it was found that obstacle has both negative and positive aspects for personnel evacuation and reasonable arrangement of tables and chairs around the exit could delay the occurrence of the peak of evacuation density.The four-person table layout and the combination of four-person and eight-person table layout have better evacuation effect.Through carrying out the simulation experiments which were influenced by double effects of obstacles and influence factors,the optimal obstacle layout that four-person table layout was found out,and then Pyrosim platform was used to analyze the fire spread situation to calculate the ASET(Available Safe Egress Time)value.The results showed that people could evacuate successfully by comparing the value of ASET and RSET(Required Safe Egress Time)and some layout optimization and emergency evacuation suggestions were proposed after analyzing the simulation process.The research strategy,experimental group,simulation methods,and the influence characteristics of the obstacles on personnel evacuation discovered in the research of college library could also be of great significance for the study of emergency evacuation and obstacle layout for public buildings.