Abstract: A combination of theory and FDS numerical simulation is used to study the control effects of the semi-transverse smoke exhaust ventilation mode and the longitudinal smoke exhaust ventilation mode on the spread of fire smoke when a fire (1.5 MW) occurs in the underground pedestrian passage. Results have shown that under the condition of equal smoke exhaust volume and different air supply volume, except for the temperature directly above the fire source exceeding 60 ℃, the other semi-transverse smoke exhaust ventilation mode controls fire smoke hazards within the critical index, which is beneficial to escape on both sides of the fire source for pedestrians. The longitudinal smoke exhaust ventilation mode controls the risk factors of fire smoke within the critical index, and most of the smoke is controlled on the downwind side of the fire source, which is beneficial for pedestrians to escape on the windward side. For underground pedestrian passage fire, from the perspective of high personnel escape efficiency, the semi-transverse smoke exhaust ventilation mode should be adopted; from the perspective that pedestrians are affected by the uncertainty of risk factors, the longitudinal smoke exhaust ventilation mode should be adopted.

Key words: underground pedestrian passage, semi-transverse smoke exhaust ventilation mode, longitudinal smoke exhaust ventilation mode, FDS, evacuation