Meteorological Effect on Temperature Field of Tunnel with High Altitude in Cold Region

To investigate the influence of meteorological conditions on the temperature distribution of the surrounding rock and lining of tunnel in seasonally frozen areas, taking into account phase change, a temperature field model was established based on the principles of continuum mechanics and thermodynamics. The effect of different meteorological conditions on the radial temperature field distribution of the tunnel was explored by varying the annual mean temperature and annual temperature amplitude in the model. Then, the spatio-temporal distribution model of temperature field in the surrounding rock was established. Results show that the latent heat of phase change is not negligible in the modelling process of tunnel in cold region. The annual average temperature has a significant impact on the freezing depth, and the freezing depth of the surrounding rock will gradually increase when the annual average temperature falls below 0°C. The freezing depth of the surrounding rock varies periodically when the average annual temperature is greater than 0°C. The amplitude of the surrounding rock temperature decreases exponentially with the increase of the radial depth of the surrounding rock. After reaching a certain depth, the amplitude of temperature tends to 0, and the average temperature of surrounding rock changes logarithmically. The conclusions provide a significant reference for the frost protection design of tunnel in cold regions.