Abstract: A simplified analytical method is proposed for the geotechnical analysis of energy pile groups under thermo-mechanical loads. The relationship between the shear stress and the relative displacement at the pile-soil interface is modeled by a hyperbolic function. The elastic shear displacement method is used to determine the deformation of the surrounding soil. Assuming the settlements induced by the adjacent piles are elastic, the shaft and base interactions among piles are considered separately. The effects of the nonlinear behavior at the pile-soil interface, the pile head restraint condition, and the location of energy piles in the pile group can be predicted reasonably. The computed interaction factor between two energy piles by the proposed method are better than those from the elastic approach. The reliability of the present method is also validated with the experimental data collected from literatures. Both the computed and the measured results show that if part of the piles are subjected to the temperature change, the foundation tilting and the redistribution of the axial load among the piles will be induced. The present method can capture the main characteristics of energy pile groups efficiently and be used as a useful analysis tool for the engineering design.

Key words: energy pile groups, thermo-mechanical loading, interaction, differential settlement, load redistribution