Analysis of Temperature Field of Tunnel Surrounding Rocks in Freezing-Thawing Environment

Abstract

On the background of large scale rocks engineering in cold regions, Temperature Field and Stress Field of Tunnel Surrounding Rock under the freeze-thaw environment are numerically analysed. According to the single temperature field equation of tunnel surrounding rock and Da Ban mountain tunnel project in Qinghai province as an example, large scale finite element software is used to simulate temperature distribution under freeze-thaw cycles, which is from the rising temperature to the decreasing temperature and from the rising temperature to the decreasing temperature again. The frost heaving force of the tunnel in the cold region is introduced and the mathematical model about rocks temperature field is also researched. Finally, finite element method is used to calculate the frost heaving force of rock tunnel in the cold regions. The results show that in the freezing and thawing environment, the area near the inner wall of the tunnel is more likely to be affected by the ground temperature and the effect of open ventilation and convection, and the temperature and stress changes more violently. In the design and construction of the cold regions, the influence of the frost heave force of the surrounding rock must be considered. Because freeze-thaw circles could cause the destruction of the tunnel structure, convective heat transfer will occur between tunnel mouth and walls and the environment, resulting in large temperature difference. Therefore, in order to reduce freeze-thaw disasters in the cold regions, we should consider the Protection measures about the hole and the wall. In this way, it reduces the range of freeze-thaw circles and prevent the convective heat transfer effectively.