Simulation Study On The Evading And Surpassing Behavior Of Pedestrians In Walking Facilities With Obstacles

With the rapid increase of urban land and population,massive pedestrian gathering and distributing becomes more and more frequent.In large-scale walking facilities such as traffic terminals,sports venues and shopping centers,spatial obstacles including walls,pillars and separation fences would obstruct pedestrian movement.In particular,unreasonable design and layout of obstacles would reduce pedestrian movement efficiency and even cause stampede in crowded and panic situations.Meanwhile,microscopic modeling and simulation could reproduce crowd macroscopic features through setting microscopic pedestrian movement rules,thus becoming the main method to study pedestrian dynamics in different conditions.Exploration into the behavioral characteristics,theoretical modeling and microscopic simulation of pedestrian dynamics could help pre-evaluate and improve the architecture layouts and pedestrian organization schemes,thus being of great significance to the improvement of pedestrian evacuation efficiency and the prevention of crowd stampede accidents.Pedestrian experiments,theoretical modeling and microscopic simulation have been implemented to explore the evading and surpassing behavior of pedestrians in walking facilities with obstacles.The relations among individual microscopic behavior,crowd macroscopic features and the effect of spatial obstacles would also be illustrated.The main research contents are as follows:Firstly,experiments on the microscopic evading behavior and crowd macroscopic features of pedestrians under the influence of obstacles have been conducted.Trajectories and evacuation time of 39 pedestrians have also been obtained to explore the mechanism of evading behavior and analyze the effect of obstacle scale,shape and layout on crowd macroscopic features.Secondly,theoretical modeling has been achieved to set the movement rules of pedestrians with evading and surpassing behavior.Based on experimental results,the conjugated forces model is constructed with the colliding time and evading time as main modeling parameters.A pair of conjugated self-driven forces is introduced to enable a pedestrian to avoid a direct collision and keep a normal velocity magnitude while confronting with an obstacle.Meanwhile,the repulsion force and friction force in the social force model have also been modified to reproduce pedestrian dynamics in non-panic situations through eliminating the compression and deformation of pedestrians.Afterwards,based on computer simulation,the microscopic evading and surpassing behavior of an individual would be reproduced,and the influence of main evading parameters on the simulation performance would be analyzed.Finally,computer simulation would be applied to explore the influence of pedestrian microscopic behavior and obstacle features on crowd macroscopic features.In walking facilities without spatial obstacles,the influence of surpassing behavior among pedestrians on pedestrian evacuation efficiency would be studied to explore the optimal surpassing strategies under different pedestrian densities and exit widths.In walking facilities with spatial obstacles,the influence of pedestrian evading and surpassing behavior as well as obstacle shape and size on pedestrian evacuation efficiency,bottleneck passing capacity and crowd macroscopic phenomena would be analyzed.Meanwhile,the obstacle-optimization methods to enhance the pedestrian evacuation efficiency and bottleneck passing capacity would be proposed.