Abstract:

The prediction of tunnel temperature field in cold region is of great significance to the freeze-proofing of tunnel. As a result, the heat transfer model of the cold and wind tunnel temperature field is deduced based on the basic methods of heat transfer and fluid mechanics and principle of conservation of energy. And then the influence of ventilation and surrounding rock conditions on the temperature field distribution of tunnel in cold region is analyzed by finite difference method. The research results show that: (1) The lower the inlet wind temperature and the larger the wind velocity and cross-section, the lower the overall temperature inside the tunnel, which due to more cold wind; for every 5 ℃ decrease of inlet wind temperature, the average temperature of air flow inside the tunnel at the same position decreases by 3. 8 ℃. (2) The wind temperature determines the surrounding rock temperature in a certain range from the wall surface; the lower the air temperature, the greater the freezing depth and the affected surrounding rock range. (3) The initial temperature and thermal conductivity of surrounding rock determine the radial temperature distribution curve of surrounding rock; the larger the thermal conductivity of surrounding rock is, the flatter the temperature distribution curve is. Moreover, when the initial rock temperature increases by every 5 ℃, the freezing depth will decrease by 0. 24 m, and the radial depth of affected surrounding rock will decrease by 0. 32 m.

Key words: tunnel engineering, tunnel in cold region, finite difference, the temperature