Risk Analysis of Pedestrians Evacuations Based on Crowd Energy

Abstract

The crowd energy is newly proposed to evaluate the crowd safety level and has a positive correlation with the risk of crowd injuries. But how to manage overcrowded pedestrians and to avoid crowd injuries from the energy-release view are still difficult problems. In this article, the crowd energy model of evaluating the risk of pedestrian evacuation is introduced based on social forces function firstly. The crowd energy model takes pedestrian kinetic energy, pedestrian potential energy and crowd internal energy into consideration, and can be used as a quantitative risk analysis on both the global level and the local level. Then, diversion railings are also discussed as a management tool to eliminate the risk in large mass-gathering and pedestrian's evacuations scenarios. In order to test our method, an agent-based simulation tool is developed to simulate the pedestrians. So the crowd energy can be calculated automatically. Finally, the influences of management measures on crowd safety is investigated in our simulated experiments and designed scenarios. The results show that additional railings can eliminate the risk of the crowd injurie risk while it can avoid excessive crowds gathered in a small area and in a very short time. But those additional diversion railings will generate more global crowd energy as a result of increases in the evacuation time. Therefore, in some emergency cases, railings are not good choices.