Evacuation from underground railway stations — Available and required safe egress time for different station types and general evaluation criteria

Abstract

Safe egress in case of a fire emergency is a major challenge for all parties responsible for the design and operation of underground railway stations. Since empirical data on egress behaviour, evacuation efficiency and smoke spread is scarce, numerical simulations are an important tool in order to determine available and required safe egress time. Egress times for different types of stations and various occupant distributions are calculated using the microscopic evacuation model ASERI. Required egress times are related to corresponding available egress times obtained from CFD smoke spread simulations by applying evaluation criteria included in the German vfdb Guideline “Methods of Fire Safety Engineering”. These investigations were part of a larger project including the local fire authorities to develop methods and criteria for fire safety concepts of existing and new subway stations in the city of Frankfurt.