Development of a three-stage hierarchical model for quick calculating stair evacuation time of high-rise building coupled with simulation analysis

Calculating the evacuation time during staircase evacuation is essential to evaluate the security conditions of high-rise buildings under emergency scenarios. A three-stage hierarchical model for calculating emergency evacuation time is constructed by combining discrete state update rules and continuous forms in computation to investigate the evacuation process of pedestrians in multi-floor buildings in emergency circumstances. Combined with simulation analysis, the model considers the capacity constraint of stairwell and congestion effects and calculates the evacuation time hierarchically. The model's validity is verified by the existing evacuation simulator for a hypothetical building case study, coupled with a comprehensive computational comparison. Calculations on entire and separate evacuation times are explored considering different stairway capacity restrictions and geometric features. Computational results demonstrated that this model is effective and may be regarded as a valid tool for staircase evacuation time calculation in the context of high-rise buildings.