Numerical Assessment of Smoke Flow and Life Safety in a Subway Station Fire

This study developed a three-dimensional numerical model of an actual subway station using PyroSim and evaluated smoke movement and life safety during fire scenarios through Fire Dynamics Simulator (FDS) simulations. A mesh sensitivity analysis was conducted to determine the appropriate mesh resolution, and the effects of smoke and ventilation system operation on smoke spread and life safety criteria were examined. The results showed that activating the system increased the available safe egress time (ASET) based on visibility from 208.5 s to 330.1 s, indicating improved evacuation feasibility. Temperature and toxic gas concentrations remained within acceptable limits during system operation. These findings demonstrate that smoke and ventilation systems play a critical role in enhancing the fire-safety performance of underground subway stations and provide foundational data for performance-based design and fire-safety strategies in underground structures.