An energy pile-soil interface characteristic apparatus（EPSICA）was developed.Energy pile model was installed in the middle of the apparatus.Different soil can be filled around the energy pile model to simulate pile in different foundations.The soil layers at different depths were simulated by applying corresponding loads on the filled soil.The temperature of energy piles was controlled by water bath cycling.The Pt100 sensors were installed in the pile and soil to measure the temperature changes.A miniature earth pressure cell was installed on the pile surface to measure the normal stress on the pile-soil interface.The FBG quasi-distributed optical fiber technology was used to measure the circumferential deformation of the pile.Taking the sand foundation as an example

the contact mechanical characteristics of pile-soil interface during the heating and cooling cycle was studied based on the temperature of pile and soil

normal stress on pile-soil interface and circumferential deformation of pile.The developed apparatus provides a new method for the study of thermo-mechanical behavior of energy pile.