Experimental study on heat storage and release characteristics of surrounding rock and soil of subway stations

Aiming at the problem of heat storage and release of surrounding rock and soil of subway stations, this paper takes a station of Shanghai Metro Line 12 which has been in operation for five years as the research object, and the outdoor air temperature, the station air temperature and the wall heat flux density of the station hall are measured for one year. The heat storage and release characteristics of the surrounding rock and soil of the subway station and its positive effect on maintaining the air temperature stability of the station are analysed. The test results show that the surrounding rock and soil of the subway station is mainly endothermic in the transition season and summer, and mainly exothermic in winter. The net annual heat storage and release is -5 743 MJ, the heat absorption is 36 069 MJ, and the heat release is 30 326 MJ. Through heat storage and release, the surrounding rock and soil effectively restrains the influence of outdoor air temperature fluctuation on the air temperature in the station.