A finite layer analysis method proposed for energy pile modeling under coupled thermo-mechanical loads

Abstract

This study proposes a new hybrid analytical and numerical approach to analyze energy piles by coupling thermal and mechanical loads. Conceived through the finite unit method, the Finite Layer Analysis Method (FLM) boasts promising results when applied to energy piles in soil, which is typically layered or multilayer mediums. This methodology effectively reduces a complex, three-dimensional geotechnical problem to two dimensions, yielding marked improvements in computational efficiency. The FLM for energy pile consists of temperature field calculation and thermo-mechanical coupling calculation, for which the theory and derivation are carefully introduced and elaborated. To validate the accuracy and robustness of the newly proposed FLM method, both the temperature field calculation and the thermo-mechanical coupling calculation are verified meticulously with the finite-length heat source analysis theory, together with the Finite Element results. The validations are also performed against a variety of field trial data including those from London and Lausanne tests.