Simulation of the influence of spatial obstacles on evacuation pedestrian flow in walking facilities

In order to research the influence mechanism of spatial obstacles on evacuation pedestrian flow, simulations of pedestrian evacuation are carried out by using the improved dynamic parameter model based on cellular automata. A retardation coefficient is introduced to describe the effect of obstacles slowing down pedestrian movement. A special technique is adopted to calculate the shortest estimated distance (SED) from cell site to exit considering obstacle layout and retardation coefficient. The repulsion and isolation effect of obstacles on pedestrian flow is manifested by the clusters of evacuation path chains. The movement probability is considered to narrow the gap between the normal speed and simulated evacuation speed caused by spatial discretization. The effectiveness of movement probability is verified by theoretical analysis and simulation results. It is found that in evacuation from a walkway, the influence of retardation coefficient on evacuation time will be gradually weakened and stabilized with walkway width rising. The influence of obstacle layout on the selection of evacuation path will be observed in the classroom. It also shows in the evacuation through an exit with a prepositive obstacle that the evacuation time is determined by the narrowest one in the series-connected bottlenecks. Moreover, the phenomena such as "pedestrians keeping a certain spatial distance from the boundaries of walkway'', "pedestrians preferring to choose a wider movement aisle in classroom'' and "evacuation time being dominated by the narrowest one of series-connected bottlenecks'' can also be observed during pedestrian evacuation in the simulation. (C) 2021 Elsevier B.V. All rights reserved.