Performance-Based Analysis for Air Flow through Crossover Sections of Metro Tunnels

Creative Commons License

Bulut B., Öztürk Ö., Kayhan C.

Ninth International Seminar on Fire and Explosion Hazards, Sankt-Peterburg, Russia, 21 - 26 April 2019

  • Publication Type: Conference Paper / Unpublished
  • City: Sankt-Peterburg
  • Country: Russia
  • Hacettepe University Affiliated: No


Critical velocity is crucial in the design of tunnel ventilation system as the system is designed to prevent back layering in emergency situation to help passengers’ safe evacuation along the tunnel. Due to a revision in the critical velocity equation [1], the revised calculations yield higher critical velocities, especially for relatively low design fire loads – such as for metro and light rail transit systems – with respect to higher design fire sizes of road tunnel.

This study focuses on the crossover sections of the tunnels. An existing generic station along one of İstanbul metro lines is selected as the case study. The station has its dedicated tunnel ventilation fans operating and is one of the largest stations with over approximately 2,000,000 passenger circulation, monthly. Track line entering the station consists of three crossover sections where the lines converge and these crossover sections form the basis of the study. For the system reliability, pedestrian flow simulation is performed to demonstrate ASET/RSET analysis.