Preliminary Prediction of Temperature Field and Thermal Hazards in the Water Diversion Tunnel of the “Yellow River to Xining” Project

As tunnel engineering advances towards greater depths, larger scales, and longer distances, high rock temperatures and tunnel thermal damage frequently occur, constituting some of the main geological hazards faced by transportation, water conservancy, and other tunnel engineering projects. In this study, we take the alternative option to the No.1 deep-buried water diversion tunnel of the “Diversion of Yellow River to Jining” project as the study area, combined with the geological data of the field investigation, to comprehensively consider the thermodynamic properties of the rocks along the tunnel and the logging data along the tunnel, and we use the least squares method to fit the temperature of the logging wells to obtain the thermal background parameters of the earth’s heat flow as well as other regional heat background parameters to obtain the thermal background parameters of the tunnel. The COMSOL Multiphysics software established a two-dimensional steady-state geothermal field numerical model to predict the rock temperature along the tunnel. The results show that the maximum temperature along the tunnel is 51.1 °C, the length of the tunnel with thermal damage class I is 45.9 km, the length of the tunnel with thermal damage class II is 18.4 km, the length of the tunnel with thermal damage class III is 8.0 km, and the length of the tunnel with thermal damage class IV is predicted to be 0.18 km. Compared with the on-site temperature measurement data, the model prediction error is within ±1.5 °C, which validates the accuracy of the model. This study adopts numerical simulation combined with field geological and logging data to provide a theoretical basis for tunnel heat hazard prevention. Meanwhile, it offers technical support for the design and construction of similar deep-buried high-temperature tunnels.