Numerical study on surrounding rock mass temperature field of Kangding tunnel no. 2 considering wind flow

Based on the Kangding Tunnel No. 2 project, this study analyzes the heat exchange between air and the rock mass surrounding the tunnel under wind flow by the finite difference method. The influence of factors on the temperature field of a tunnel in cold regions, including ventilation and initial conditions, is investigated. The results show that: 1) The lower the air temperature, the greater the wind speed, the larger the rock mass temperature influence circle and the greater the frozen depth; 2) When the wind speed is less than 3 m/s, its change has an obvious impact on the rock mass temperature; 3) For every drop of 5 °C in air temperature, the frozen depth increases by about 5 m, indicating that the air temperature is an essential factor affecting the rock mass temperature regime; 4) The higher the initial rock mass temperature is, the smaller the influence circle on the rock mass is. And to a certain extent, it determines the temperature distribution in the rock mass within a specific range from the wall surface.