Research On Emergency Evacuation Of Large Passenger Flow In Xi'an Metro Transfer Hubs

Since the opening of the London Metropolitan Railway,the world's first underground rail transit system,in 1863,urban rail transit has rapidly developed into an essential part of the public transport system in large cities with a population of more than one million.In China,urban rail transit has become one of the most important modes of transportation in people's daily life.With the characteristics of fast,convenient,safe,large transportation volume and high transportation efficiency,the subway has become the preferred mode of transportation for residents.As the rail transit hub station is an underground space with long evacuation routes and few exits,the increase of peak passenger flow will directly cause the transfer hub station to be overcrowded.In case of fire and other emergency events,it may cause massive casualties and property losses.Therefore,how to efficiently evacuate the large passenger flow of the subway transfer hub station is an important issue to be studied.According to the background of the Xi'an metro transfer hub and problems of the emergency evacuation,this paper proposes a comprehensive emergency evacuation model of large passenger flow based on the improved social force model and multiple exits model.Firstly,using the literature-summarizing method to select the representative indexes for the first grade,determining the second-grade indexes through the expert interview based on the background of Xi'an metro,establishing the evaluation index system by AHP,constructing the judgment matrix to determine its weight,carrying out the single level ranking and the total level ranking respectively by the consistency test,and calculating the total weight of each index for classification.Then,identifying the problems of emergency evacuation of Xi'an metro transfer hub;secondly,analyzing the passenger flow characteristics of Xi'an metro transfer hub under both normal conditions and emergency conditions according to the pedestrian behavior theory;then,based on these characteristics and the vulnerability factors of an emergency evacuation,considering the attributes of Xi'an Metro and the impact of crowd density on the expected speed,the classic social force model is modified,and adding the effect of attraction on pedestrians on classical one and according to the exit characteristics of the Xi'an metro transfer hub and the pedestrian congestion behavior,modifying the multi exit,selection model.Making the combination of two models and establishing a comprehensive emergency evacuation model of large passenger flow based on the improved social force model and multiple exits model;based on the model,AnyLogic software is mainly used to simulate both dynamic and static emergency evacuation signs,observing the changes of evacuation time and evacuation efficiency,and make a comparative analysis,change the width of the exit to inspect the evacuation time and the number of pedestrians attracted by each door;finally,from the simulation results and the AHP,the emergency management problems of Dayanta station are analyzed under the background of large passenger flow of railway transfer hub,the optimization countermeasures are provided in four aspects:station physical facilities,personnel organization,passenger flow direction,and traffic organization schemeThis paper discusses the vulnerability factors of Xi'an metro transfer hub,analyzes the behavior of evacuees and the distribution of large passenger flow under both normal and sudden large passenger flow,and establishes a comprehensive emergency evacuation model of large passenger flow based on the improved social force model and multiple exits model,which provides a targeted optimization strategy for the existing problems of Xi'an Metro Emergency management department,and improves the efficiency and safety of passenger evacuation in transfer metro hub.