Abstarct: Piles that are used to harvest shallow geothermal energy in addition to transferring structural load to the soil are known as thermal piles. An energy pile has different behaviors under different loadings because of thermal and mechanical interactions. Using physical modeling, we modeled an energy pile in the dry sand of Firuzkuh and compared the bearing capacity in the two general baxse-only-restrained and both-ends-restrained conditions. For each of these two conditions, the relative densities of 48% and 85% and the temperature changes of ΔT=17°C and ΔT=30°C were regarded as variables. The soil temperature, the pile temperature, movement of the pile head and tip, and the strains generated in the pile were recorded during the test. These parameters are useful for calculating the temperature profile, pile thermal stresses, side shear stresses, and pile bearing capacity. The results showed that the increase in the relative density and temperature of each lead to an increase in thermal stress and bearing capacity. In addition, both-ends-restrained condition had more thermal stresses than the baxse-only-restrained condition because the pile head was not free. The minimum bearing capacity increase of 10% was obtained for the baxse-only-restrained condition with a relative density of 48% and ΔT=17°C, while the maximum increase of 21% was obtained for the both-ends-restrained condition with a relative density of 85% and ΔT=30°C.