Research On Pedestrian Flow Characteristics And Evacuation Simulation In The Bottleneck Area Of Subway Station

As an important part of urban public transportation,the subway carries large passenger traffic every day,which greatly facilitates our lives.However,the subway station has a large flow of people,high personnel density,and complex types of facilities.In the event of an emergency,it is easy to cause panic and crowded stampede.Therefore,it is of practical significance to simulate the pedestrian flow characteristics and evacuation in the bottleneck area of the subway station.Based on the pedestrian flow observed in five subway stations of Fuzhou,Shanghai and Nanjing,this paper uses Open CV to extract the pedestrian trajectory and analyzes the basic parameters of pedestrians.Then we substitute the observation analysis results into the improved 3D social force model,and carry out the overall simulation study on the passage area,stair area.Finally,we give evacuation strategies and suggestions for pedestrian evacuation in subway stations.The main research work is as follows:(1)Pedestrian flow observation sample data indicates that the age composition of the passenger,the sex ratio of the passenger,and the type of baggage carried by the passenger are related to the location of the subway station.(2)The basic parameters of pedestrians are obtained by the trajectory extraction software.The results show that the speed and density of pedestrian flow under one-way and two-way are linear in the channel or staircase area.The higher the density,the smaller the speed.What is more,the density of unidirectional pedestrian flow has greater impact on the speed.And the speed of unidirectional pedestrian flow is higher than the speed of directional pedestrian flow.However,due to the density,when the two-way pedestrian flow reaches the density threshold,the decreasing trend is more obvious than the one-way pedestrian flow.(3)We propose a three-dimensional social force model considering the force in the vertical direction and the horizontal direction.Then we use three kinds of evacuation strategies to simulate pedestrians on the stair area: disorderly(straight upstairs and downstairs),orderly(pedestrians move to the right when upstairs and downstairs),and middle partitions(separate movements of pedestrians when upstairs and downstairs).The study found that when there is a large number of two-way pedestrian movements,the strategy of using the intermediate partition can effectively guide pedestrians to evacuate.(4)We simulated and analyzed the evacuation trajectory of pedestrian,pedestrian microscopic density distribution and evacuation efficiency when the main channel and the branch channel are at different angles.The results show that when the angle between the main channel and the branch channel is obtuse,it can effectively alleviate pedestrian congestion.Pedestrian shunting efficiency of obtuse is better than right angle and acute angle.(5)Using the improved social force model to simulate and analyze the space-time map and density map of the single train arriving at the peak,the results show that there is a bottleneck state in the stair area leading to the hall,the gate area and the exit area near the arriving subway.We proposed the subway evacuation strategy and recommendations for this phenomenon.