Effects of Occupant Composition on Escalator Evacuation Efficiency in Subway Station Fires : Focusing on Time-of-Day Passenger Characteristics and Dynamic Evacuation Simulation

Abstract

This study aims to identify the effect of variations in user composition by time of day during a subway station fire on escalator evacuation efficiency, and to propose a dynamic evacuation route allocation method linked to escalator shape conditions. Based on Seoul subway boarding and alighting statistics by time of day, scenarios for commuting during the morning(S1), daytime(S2), and weekend(S3) were developed, and a Pathfinder simulation was conducted by cross-applying the escalator length(25·65m) with the actual on-site measured stair heights(240·215·180mm). The analysis showed that there was no difference in the final evacuation completion time(RSET) among different stair height conditions; whereas, when the length increased by 2.6 times, RSET was delayed by 52–56%, confirming that escalator length is the primary determinant of evacuation. S2, with a high proportion of elderly occupants, and S3, with a high proportion of occupant groups with children, caused similar levels of evacuation delay, suggesting that groups with children are also a vulnerability factor that should be considered in evacuation safety design alongside the elderly. Designated passage evacuation increased the bottleneck density to 4.0persons/m² or higher under all conditions, reducing efficiency, and this shows that the fixed left-right separated designated passage method should be avoided when developing disaster prevention plans. Therefore, it is necessary to introduce a dynamic route allocation method that takes into account the age composition and passenger characteristics by time of day, rather than simply separating left and right.