عنوان مقاله [English]
To collect geothermal energy various heat exchanger systems have been developed in recent years that energy piles are one most of them. Reinforced concrete piles have been widely used as a geothermal heat exchanger to access the relatively constant temperature of the ground for efficient heating and cooling of buildings. In addition to the structural role, energy piles provide a suitable field for exploiting geothermal resources. In this paper, the geotechnical challenges of the energy pile and the thermomechanical behavior of this system were investigated using the finite element software ABAQUS. This study focuses on investigating the impact that different magnitudes and combinations of thermal and axial mechanical loads have on the mechanical behavior of energy piles in dry sand. The thermal load was applied on the pile as a temperature change of 15º - 32º (ΔT = 17º C). Due to the application of the pile's thermal loading, the pile's resistance parameters are changed. In this paper, the effects of temperature changes on the axial stress, shaft friction stress, axial displacement, axial strain, and the limit load of energy piles are carried out and sensitivity analysis for understanding the behavior of energy piles in the different thermal and physical characteristics of sand were carried out. The results of numerical modeling show that, due to the application of temperature loading, the amount of bearing capacity of the pile is reduced by about 11%. Also, the thermal properties of the soil have a profound effect on thermal and geotechnical performance.