Influence of Train Location on Smoke Control in Tunnel Cross-passage

Theoretical analysis and numerical are used to investigate the critical velocity in tunnel cross-passage. Considering the effect of train blocking, several cases are built by FDS to verify whether the critical velocity can control the smoke in the cross-passage. Result indicates that the distance of the train head away from the cross-passage as 1/2 power of the tunnel velocity. With the train crossing the cross-passage, the value velocity of the cross door increase gradually and then decreases when the middle of the train stocking in the door of cross-passage. The maximum value of velocity is greater than the critical velocity calculated by Froude model and the smoke diffuse to the cross-passage. In other cases, the velocity fails to prevent the soot propagation from accident side of the tunnel and the gas full of the cross-passage cause risk of evacuation.