Study On Evacuation Time And Evacuation Characteristics Of Special Population In Multi-Storey Buildings

With the increase of modern population and the acceleration of the aging process of society,the number of disabled population and the elderly population is gradually increasing,so the study of evacuation of special population has more and more important practical significance.When evacuating special groups,others may be needed to help them evacuate,which will change the speed and volume of evacuation,and easily lead to falls and stampedes,resulting in serious casualties.Therefore,it is necessary to analyze the evacuation speed,evacuation rules and crowded characteristics of the special population when assisting evacuation,so as to provide reference for the design of residential buildings for special population and evacuation scheme.At present,the research on assisting behavior of special groups mainly focuses on evacuation of the elderly,while there are few studies on normal evacuation and assisted evacuation of the disabled.The conclusions of the research on evacuation of the elderly cannot provide reference for evacuation of the disabled.In addition,cellular automata simulation is mostly used in the simulation of assisting behavior.In this case,evacuation scene is a two-dimensional model,and the problems of personnel collision and vertical path selection are ignored.In order to solve the above problems,this paper uses Pathfinder software to conduct evacuation simulation for a special population living building,analyzes the evacuation characteristics of special population under different assistance ratios and evacuation modes in multi-storey buildings with different levels,and summarizes the optimal evacuation scheme according to the principle of optimal evacuation time,congestion degree and range.The research and conclusions of this paper are as follows:1.According to the characteristics of the special population and the assisting combination,the Pathfinder software is used to construct the models of different evacuation populations.2.Conduct crowd evacuation simulation for a barrier-free building with different assistance ratios,analyze the evacuation speed of stairwell,which is the most significantly affected factor when the assistance ratio changes in actual evacuation,and study the relationship between evacuation time and stairwell evacuation speed.The results show that stairwell is the area with the most significant impact on evacuation time in evacuation of special people.Then,a two-story stairway evacuation model for special people is designed,four different working conditions are set,and the changing rules of the influence of the assistance ratio on the horizontal plane and stairwell for special people and normal people are analyzed.It is concluded that :1)when the evacuation floor increases,the influence weight of horizontal speed on evacuation time will gradually decrease,while the influence weight of vertical evacuation speed will gradually increase.2)In low-rise buildings with two or three floors,the evacuation time changes with the assistance ratio in a U-shaped curve,and the evacuation time reaches the minimum value when the assistance ratio is 40%.3)In multi-storey buildings with 4 and 5 floors,the optimal evacuation time of different assistance ratios presents a trend of slowly increasing first and then rapidly decreasing,reaching the maximum evacuation time at 40% assistance ratio and the minimum evacuation time at 100%assistance ratio.3.This paper analyzes and compares the evacuation characteristics of special population under the influence of different assistance ratios in multi-storey buildings with different floors,defines the change rule of optimal evacuation time of special population with the storey and assistance ratio,and concludes that when the assistance ratio is less than 50%,evacuation time of three-storey buildings has little change with the assistance ratio,and when the assistance ratio is greater than 50%,evacuation time of three-storey buildings increases with the increase of assistance ratio.The e evacuation time of four-and five-story buildings decreased significantly with the increase of assistance ratio.The innovation of this paper mainly lies in that through the evacuation simulation of special population in multi-storey buildings under different assistance ratios,three evacuation modes of unlimited evacuation of special population,only using stairs and only using elevators are set up to get the evacuation characteristics of special population in buildings of different storey,and put forward the effect of assistance ratios on evacuation of special population.