A non-uniform temperature field in the ground forms during the utilization of the shallow geothermal energy

which results in a dynamic temperature difference on opposite sides of the foundation pile. The temperature difference may cause the bending deformation of the pile. A non-uniform temperature field was constructed in an experimental model. The temperature of soil

as well as the temperature and strain on opposite sides of the pile was investigated in the process of temperature balance. The effect of non-uniform temperature field on the internal force of pile was analyzed. The experimental results show that the non-uniform temperature field will cause bending deformation in the pile body according to the FBG strain sensors. The distribution of the bending moment along the depth of the pile is related to the temperature difference. Therefore

the influence of non-uniform temperature field on the internal force of the geo-structure should be taken into account in the applications ground source heat pump system. It is of great significance to conduct related researches to reveal the internal force variation of the foundation pile.