Study on the Freeze-Thaw Process of the Lining Structures of a Tunnel on Qinghai-Tibet Plateau with the Consideration of Lining Frost Damage

In seasonally frozen ground, there are many frost problems in highway road tunnel after its excavation due to the heat exchange between cold air and lining structure inside tunnel. To mitigate these frost-related damages, thermal insulation layer is widely used at entrance exit sections of this study, a coupled mathematical model heat, moisture, stress was built for tunnels permafrost regions. Then, based on field-observed temperature roadway Altun Mountain Qinghai-Tibet Plateau (QTP), seasonal freeze-thaw process surrounding rocks (SR) structures were numerically investigated with consideration methods: without (WTIL) laying inner surface second (STIL). Combined principle Miner damage accumulation, regimes WTIL STIL. The results show that significantly disturbance SR excavation. 5th year operation period, maximum freeze depth (MSFD) can reach 1.6 m vault arch inverted only 1.0 pavement both absolute value principal (MAPS) minimum (MIPS) season bigger than those warm comparing filed structure. same way, MAPS MIPS STIL numerical simulation. positions tensile primary arch. For structures, greater generally harmful. Thus, should be laid layer.