Discrete Element Crowd Model for Pedestrian Evacuation Through an Exit

TL;DR

This paper introduces a discrete element model simulating pedestrian crowd evacuation through an exit, capturing different flow states and clogging phenomena based on desired velocities.

Contribution

It presents a novel granular dynamic model using self-driven spheres and anisotropic forces to better understand crowd flow and clogging during evacuation.

Findings

Crowd flow shows smooth, transition, and phase separation states.

Higher desired velocities increase clogging risk and can block the exit.

Faster-to-frozen effect occurs at velocities of 1.6 m/s or above.

Abstract

A series of accidents caused by crowd within the last decades evoked a lot of scientific interest in modeling the movement of pedestrian crowds. Based on discrete element method, a granular dynamic model, in which human body is simplified as self-driven sphere, is proposed to simulate the characteristics of crowd flow through an exit. In this model, the repulsive force among people is considered to have an anisotropic feature, and the physical contact force due to body deformation is quantified by the Hertz contact model. The movement of human body is simulated by applying the second Newton's law. The crowd flow through an exit at different desired velocities is studied and simulation results indicated that crowd flow exhibits three distinct states, i.e., smooth state, transition state and phase separation state. In the simulation, clogging phenomenon occurs more easily when the velocity of desired is high and the exit may as a result be totally blocked at a desired velocity of 1.6m/s or above, leading to faster-to-frozen effect.