Assessing the Need for Additional Evacuation Measures in Deep Underground Stations

Underground railroad stations face evacuation challenges owing to the rapid spread of smoke and extended escape routes during fires. Evacuation in deeply underground domestic railroad stations relies solely on stairways, with no legal standards for additional evacuation methods. In contrast, international standards such as NFPA 130 and Japan’s Fire Protection Engineering Association (JAFPE) recommend using evacuation elevators as a supplementary means of evacuation. This study analyzed smoke behavior in deep underground railroad stations through fire simulations at the Soongsil University and Guryong station. It also examined additional evacuation measures to enhance evacuation safety through evacuation simulations. The results show that during a fire, smoke spread follows the same path as the passenger evacuation routes because of the chimney effect. Even with smoke control and ventilation systems in operation, smoke follows the same evacuation routes, such as stairways or escalators. Therefore, the study concluded that evacuation elevators should be installed as an additional means to improve evacuation efficiency, and placed in smoke-protected evacuation routes. The study also found that combining evacuation stairways and elevators significantly enhances the evacuation efficiency.