Emergency Evacuation in Urban Underground Loop Fire Scenarios: A Case Study

This study takes an urban underground loop in design stage as an example and proposes the evacuation control plans for underground loop fire scenarios based on the idea of hierarchical zoning and fire classification. The utilization rate of available safe evacuation time is proposed to represent the evacuation efficiency of different plans. VISSIM and Pathfinder software are used to construct simulation scenarios. The results show that the most effective evacuation strategy for different fire sizes is to keep all entrances and exits open. However, during a large-scale fire, it is not advisable to open the parking lot entrance near the fire source for vehicle access to prevent fire incidents in adjacent areas. Moreover, when a fire occurs in Area II, emergency evacuation is relatively convenient, while in Area IV, it is more challenging and requires careful monitoring. Strengthening the fire prevention capabilities in Area IV should be considered.