The mechanical response of energy pile groups in layered cross-anisotropic soils under vertical loadings

• Published in: Energy (Oxford) Vol. 292; p. 130531
• Main Authors: Ai, Zhi Yong, Feng, Wei Yong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2024
• Subjects: Boundary element method (FEM-BEM); Coupled finite element method; Cross-anisotropy; Energy pile groups; Layered soils; Vertical loading; Cross-anisotropy; Vertical loading; Energy pile groups; Coupled finite element method; Boundary element method (FEM-BEM); Layered soils
• ISSN: 0360-5442
• DOI: 10.1016/j.energy.2024.130531

The mechanical response of energy pile groups in layered cross-anisotropic soils under vertical loadings is studied with the aid of the coupled finite element method - boundary element method (FEM-BEM). The single energy pile is simulated based on the finite element theory, which then is extended to energy pile groups. The global flexibility matrix for soils is obtained by considering the coupling effects of vertical and thermal loadings. The coupled FEM-BEM equation for the interaction between energy pile groups and soils is derived based on the displacement compatibility condition at the pile-soil interface. According to the displacement coordination condition and force balance in the rigid cap, the displacement of the cap and axial forces of pile groups can be solved. The presented theory is validated by comparing the calculated results with numerical simulations and field test results in existing literature. Finally, effects of the thermal loading, pile-soil stiffness ratio, pile spacing, cross-anisotropy of Young's modulus and the stratification are discussed. •Finite element theory of single energy pile is extended to energy pile groups under vertical and thermal loadings.•Global flexibility matrix of media is obtained by considering coupling effects of vertical and thermal loadings.•Coupled BEM-FEM is used to study the mechanical response of energy pile groups in layered cross-anisotropic soils.•Effects of thermal loading, pile-soil stiffness ratio, pile spacing, cross-anisotropy and stratification are discussed.