Mechanical characteristics of supporting structures for high geo-temperature tunnel

High geo-temperature is a serious constraint to the construction and safe operation of underground engineering, will be studied based on a diversion tunnel in Xinjiang. According to the geological data, six different temperature boundaries were chosen. The deformation and stress characteristics of the surrounding rock and supporting structures were studied under four operating conditions such as spraying shotcrete, pouring concrete and flowing water. The research shows that the high geo-temperature has a marked impact on tunnel's stability, the axial force of bolt was 294 times as those which did not consider temperature, while the circumferential tensile stress was about 2.13 times; the insulating layer worked dramatically well, the axial force of bolt and circumferential tensile stress of lining were bigger if without insulating layer; the cold water had big impact on the lining stress, circumferential tensile stress of lining was 2.65 times as that without water flowing. The research results provide reference for the design and construction of similar project.