Numerical simulation of the influence of pile geometry on the heat transfer process of foundation soil in permafrost regions

Abstract

The influence of different concrete foundations on permafrost is not only reflected in the disturbance to the foundation soil during construction, but also in the influence of the difference in the long-term heat transfer process of different concrete foundation geometric forms on the frozen soil temperature. In this paper, the numerical simulation method is used to simulate the change process of the ground temperature after the construction of the cast-in-place pile foundation and the cone-cylindrical pile foundation through the established hydro-thermo coupled numerical model. Numerical simulation results show that the influence of pile foundation geometry difference on foundation soil temperature is mainly controlled by the lateral size of pile foundation, and the disturbance of pile foundation to foundation soil will not increase with the increase of pile length. The heat flux channel is formed between the pile foundation and foundation soil. When the external temperature is positive, the heat flux continues to flow to the bottom of the pile foundation, making the foundation soil temperature at the bottom of the cone-cylindrical pile foundation significantly higher than that of the cast-in-place pile foundation in summer. This study can provide reference for the design and construction of pile foundations in permafrost regions.

Keywords

• Permafrost region
• Thermal regime
• Pile foundation
• Numerical simulation