Experimental study on evolution characteristics of heat reservoir of wall rock in underground railway tunnels

By a scale model experimental test, analyses the evolution characteristics of the heat reservoir of wall rock in underground railway tunnels for seventeen years from new to long-term operation with periodic and dynamic air temperature conditions. According to its variation characteristics with time, divides the soil temperature distribution into the dynamic expanding period and the dynamic stable period. Presents the evolution characteristics of soil temperature with depth and the heat storage and release, and points out that the soil heat reservoir thickness is 20 meters with the peak temperature of the soil heat reservoir at 22.7 ℃ and the soil heat reservoir characteristic thickness at 2 meters. All of work provides the references for solving the tunnel temperature problems in long term underground railway operation.