Study on full-scale experimental and numerical investigation of fire-induced smoke control in an underground Double-Island Subway Station

Abstract

Effective smoke control in densely populated subway stations is crucial for safe passenger evacuation during a fire. This study conducted two full-scale fire experiments in the hall and platform of a double-island subway station. The characteristics of smoke flow and the effectiveness of smoke exhaust systems were evaluated by analyzing the vertical temperature distribution and CO/CO₂ levels in key regions. Fire Dynamics Simulator (FDS) was further employed to optimize key factors, such as ceiling perforation rate, smoke reservoir utilization, and vent orientation. The results demonstrated that, although smoke removal at breathing height generally met fire safety requirements (i.e., temperature below 30 °C, and CO and CO₂ levels under 1.2 ppm and 500 ppm, respectively), an insufficient ceiling perforation ratio hindered smoke storage, causing some fire smoke to spread along the ceiling as jet flow. Using FDS, the study found that the optimal design included a smoke reservoir utilization rate of 40 %, a ceiling perforation rate of 40 %, and upward-oriented exhaust vents. This study aimed to enhance understanding of smoke control effectiveness and offers insights for designing fire-induced smoke control systems in underground double-island subway stations.