The effect of geometric layout of exit on escape mechanism of crowd

In dense crowd evacuation, especially in emergencies such as fires, the safe evacuation of large public facilities will face major challenges. At the same time, as cluster congestion tends to occur in the space where the flow rate drops sharply, the superposition of fire incidents and bottleneck areas can easily evolve into malignant disasters and crowd stampedes with serious harm and influence. In this paper, Massmotion based on social force model is used to carry out a numerical simulation on exit position and corner exit form to find out the mechanism and influence law of the slight architectural adjustment on the flow at bottleneck. The results show that the traditional middle exit design is not the best, and the evacuation efficiency of the corner exit is higher than that of the middle exit. Compared with other corner exits, the average time interval between two adjacent persons passing through the bottleneck under the 30° corner exit is the shortest, and the probability of outlet clogging drops the fastest, exceeding 18% of the slowest descending speed. At the 0° corner exit, the waiting time cost of pedestrians is high and the risk of evacuation is high. The outcomes of this work can provide reference for the structural design of the building and the safe evacuation of personnel, so as to improve the evacuation efficiency and safety of pedestrians in the building to some extent.