Prediction of Freezing Air Temperature Distribution in the Entire Railway Tunnel According to Tunnel Length and Outside Air Temperature

Railway tunnels have been constructed mainly in cold regions in South Korea recently, and damage related to freezing problems have occurred thereafter. When freezing air temperatures persist inside a tunnel, it causes damage, such as ice formation from leaks and obstruction of drainage flow. The air temperature distribution inside a tunnel is related to the area inside a tunnel, such as tunnel length, cross-section, and so forth. It can be interpreted with a convection mechanism. Tunnel length is designed depending on site conditions, and it is complicated to predict freezing air temperature distribution in a tunnel. In this study, the air temperature variation inside a long tunnel was measured in winter, and a heat transfer analysis model was implemented. A double-track railway tunnel model with a half-length ranging from 500 to 5000 m was simulated, and the conditions of freezing temperature distribution inside tunnels were investigated. The research results propose freezing conditions in railway tunnels according to tunnel lengths and minimum outside air temperatures.