Study Of Pedestrian Movement Characteristics And Evacuation Behaviors In Seat Aisle Area Of High-speed Train

High-speed train is the most important means of long-distance transportation,and in recent years,passenger safety evacuation problems have attracted significant attention.As seats are usually distributed densely in the passenger cabin,the main space of the cabin is only the narrow seat aisle area,i.e.,a typical type of evacuation bottlenecks.In case of emergency,passengers should first enter the seat aisle and then evacuate towards the exits.Within the seat aisle area,the occupant density is usually quite large,and passenger evacuation behaviors could be complicated.Some passengers might carry their personal belongings or push others while evacuating.Moreover,there could be many evacuation conflicts in the seat aisle area.Therefore,pedestrian movement characteristics and evacuation behaviors deserve further discussion.Based on the studies of pedestrian dynamics and evacuation simulation methods,the issue of safety evacuation can be better investigated.In this study,pedestrian movement characteristics and evacuation behaviors in the seat aisle area were investigated,using controlled experiments and numerical simulation.The main procedures and conclusions of this research are as follows.(1)To study pedestrian movement characteristics,experiments were conducted for individual walking and single-file pedestrian walking,and the impacts of the seat aisle width and luggage was investigated.For individual walking,the pedestrian walking speed was discussed.For single-file pedestrian walking,the main analysis was directed to the measurement of the movement speed,distance headway,and the fundamental diagram.The experimental results and conclusions will directly contribute to the data input of research in evacuation simulation.In the individual walking part,the pedestrian walking speed was approximately 1.4 m/s for a normal walking condition and 1.7 m/s for a fast walking condition,and the seat aisle width was 0.5 m.An aisle width of 0.4 m could be wide enough to allow fluent pedestrian walking.If pedestrians were carrying trolley cases,the walking speed was significantly reduced,with a slight increase in the step frequency and an evident decrease in the step size.In the single-file pedestrian walking part,the pedestrian tended to maintain a safety distance of approximately 0.7 m while walking.The walking speed increased approximately linearly with the distance headway.In addition,the fundamental diagram of the pedestrian dynamic in seat aisle area presented similar results as that in the open environment.In fact,the seat arrangement did hinder the pedestrian movement,and it introduced more volatility to the experimental results.(2)To study pedestrian evacuation behaviors,evacuation experiments were conducted for different seat aisle widths and evacuation directions.The evacuation time,crowdedness,evacuation order,and aisle conflicts were discussed.The experimental results will be an important reference for the evaluation of simulation studies.The experimental result shows that the specific flow rate of the aisle gradually decreased as the seat aisle width increased,for the cases of a width of approximately 0.5 m.Moreover,it is observed that the evacuation order was mainly determined by the seat row number.Occupants from the front rows could leave the aisle area earlier.In that regard,based on the idea of a classic conflict model,a dynamic probability model of aisle conflict was developed,to describe the phenomenon of seat aisle conflict.By summarizing the results of aisle conflict events,the model weights were finally obtained and used to explain the winning probability of pedestrians from different incoming directions.(3)Based on the experimental work,evacuation simulations were conducted.Evacuation models applicable for the seat aisle area were introduced,and then the simulation methods were then discussed.Furthermore,a new agent-based model was proposed in this numerical work.The simulation parameters of the social force model and an agent-based model were also determined.By means of programming tools and algorithms,an evacuation simulation program was developed.Evacuation scenarios of the seat aisle area were simulated using the social force model and agent-based model.By comparing the numerical and experimental results,the agent-based model was found to be more competent in these scenarios of the seat aisle area,from the perspectives of evacuation order,evacuation flow rate,and crowdedness.Finally,more complex scenarios of passenger evacuation were performed,to prove the practicality of the agent-based model.This study can provide guidance for passenger safety evacuation and the design of similar vehicle cabins.Some future research prospects are proposed at the end.