Filed test of temperature field of the surrounding rocks of high temperature in the Gonggerer diversion tunnel in Xinjiang

In order to examine the distribution characteristics of temperature field of the high-geothermal diversion tunnel, this paper relies on the high-geothermal tunnel section of the Gonggeer diversion tunnel in Xinjiang and sets up a temperature monitoring test tunnel in the surrounding rocks. By using the self-designed surrounding rock temperature monitors, the surrounding rock temperature of the test tunnel during construction, operation and simulated overhaul period was tested. The temperature distribution characteristics of the tunnel surrounding rock under different conditions were obtained. The results show that the temperature of the surrounding rocks tends to be stable for a certain distance from the center of the tunnel in the high-geothermal section of the tunnel. With the deepening of the surrounding rocks, this temperature value no longer changes. From the deep part of the surrounding rocks of the tunnel wall and close to the tunnel wall, the temperature of the rock mass decreases exponentially. The influence distance of tunnel excavation disturbance on the temperature field of the rock mass is about twice the tunneling radius. After the excavation of the tunnel construction, the surrounding rock temperature will not be smaller due to the completion of excavation, but the temperature will further increase due to the closure made by the tunnel supporting structure (spray layer and lining). For the temperature of the surrounding rocks in the high temperature section of the Gonggerer diversion tunnel in Xinjiang, the temperature difference between the depth and tunnel wall of the surrounding rocks can be considered as 40 ℃. The temperature difference between the depth and the wall of the surrounding rocks during the overhaul can be considered as 25 ℃.