Study on cooling measures and ventilation cooling device of high ground temperature tunnel

As the number of tunnels continues to increase, there are more and more tunnels crossing the high geothermal strata. This study aims to address the issue of heat damage caused by high geotemperature in tunnels that cross such strata. Field tests were conducted to reveal the temperature variation law of high temperature tunnels during construction. Numerical simulation was employed to identify the influence characteristics of air volume and temperature on ambient temperature in tunnels. A ventilation system that adjusts according to the change of ambient temperature was designed, wherein the air supply volume and temperature can be modified based on monitoring of the tunnel environment and the temperature variation law. To minimize the diffusion of tunnel surrounding rock temperature into the tunnel, the study investigated the impact of insulation layer thickness and thermal conductivity on the tunnel's air temperature and proposed a rational layout of the insulation layer. Based on the above research, we obtained comprehensive control measures for tunnel high geothermal involve both an insulation layer and ventilation cooling system.