Experimental study on the temperature distribution in a cross-type interchange subway station fire scenario

Abstract

In order to investigate the temperature distribution beneath the subway ceiling, a series of experiments were carried out in a 1:20 small-scale model of a three-level cross-type interchange subway station. The experimental model contains three floors, including two lines of the metro. The experiment results show that the maximum temperature below the ceiling in the cross-type interchange subway station is slightly higher than the maximum temperature below the ceiling under the unconstrained space burning, because the complex structure of the transfer station affects the flow of the fire-induced smoke. The maximum temperature model proposed by Alpert was modified by analysing the experiment results of the highest temperature below the ceiling in the small-scale cross-type interchange subway station, and the new prediction formula for the maximum temperature excess was proposed. When the distance between fire location and side wall is 1.5 times the tunnel height, the modified coefficient of maximum temperature excess is 1.1348 based on the model proposed by Alpert. This study on this issue may benefit the current design of fire protection measures for the platform ceiling.