Research on the crowd evacuation in the classrooms based on the wave equation in seismic environments

In seismic environments, the state of crowd movement in a conventional classroom differs significantly from that of steady-state evacuation. An improved social force model based on the wave equation theory is proposed to improve the authenticity of crowd movement in classrooms under the simulated seismic environment. The optimized model first extracts the evacuation velocity values in diverse scenarios by combining the video data of crowd evacuation in real-life seismic environments, and then corrects the expected speed values of the social force model, so that the optimized model is suitable for crowd evacuation in seismic environments. Secondly, the diffusion process of the wave equation is analogized to the spread process of individual panic during an earthquake. Different individuals are affected by the superposition effect of seismic waves from different directions, which is directly manifested in the interactions that affect the acting forces in the social force model. This enables the optimized model to accurately depict the nonlinear interactions between pedestrians and between pedestrians and obstacles in seismic environments. Experiments are performed by integrating a self-built simulation platform with actual seismic data. The experimental results show that the ideal expected speed range in seismic environments is 1.6−3.2m/s, and the wave equation is effective in characterizing the panic of pedestrians, and the overall stress trend of the optimized model is consistent with the actual seismic environment. Therefore, correcting the expected speed and using the wave equation to characterize the panic of pedestrians provide an effective theoretical approach for crowd evacuation in classrooms when an earthquake occurs.