Performance study of energy piles in different climatic conditions by using multi-sensor technologies

Abstract

Abstract Energy pile is widely utilized for the thermal solicitation of the shallow geothermal energy in recent years. However, the thermo-mechanical performance of the energy pile under different climatic conditions has rarely been discussed in the existing literature. Thus, to investigate the performance of the energy pile in different climatic conditions, this study set up an experimental system consisting of multi-sensor technologies, especially the monitoring method of fiber Bragg grating. Then tests with a model pile are performed to study the performance of energy pile in heating and cooling demand dominated climatic conditions, respectively. The results show that the cumulative effect occurs in the soil temperature field in the cooling demand dominated climatic condition. Moreover, the thermally induced axial stress and irreversible displacement increase with thermal cycles in different climatic conditions. Also, this study confirms that FBG sensors are suitable for monitoring stress variations of energy piles.