A simple method for numerical modelling of energy pile's mechanical behaviour

Abstract : A commercial numerical code was used to simulate the mechanical behaviour of energy piles under thermo-mechanical loadings. The thermal load was simply simulated by imposing to the pile volumetric strains calculated from the coefficient of thermal expansion of the material. Simulation was performed for two existing in-situ experiments and one experiment performed using physical model in laboratory. Comparison between the simulation and the experimental results shows that this decoupling method can predict satisfactorily the phenomena observed experimentally: (i) pile head movement under thermal cycles at various mechanical loads; (ii) change of pile axial load along the pile under thermal cycles. The results highlight the important role played by the thermal volume change of the pile on the mechanical behaviour of the energy pile under thermo-mechanical loadings.