Numerical Simulation of Thermal Load Stress Development on Thermo-Activated Pile Foundation

Abstract

Thermo activated pile foundation is a combination of a pile foundation for supporting structural loads of building and heat exchanger to fulfill the demand for heating and cooling in the building. A closed-loop of pipe filled with a heat carrier fluid, embedded inside the concrete pile to extract and release ground heat. This paper focuses on the simulation results on structural and thermal analysis of thermo activated pile foundation model using software Abaqus/CAE. The numerical simulation indicates that thermal stress has a crucial character in deciding the working capabilities of the structure. The key finding of the simulation is that the performance of thermo activated pile foundation system can withstand the thermal load raised due to a temperature variance of less than 10˚C between the heat carrier fluid and ground. Heat transfer between fluid and ground is a conduction phenomenon so the simulation result shows that it is not recommended to increase the thickness of concrete for withstanding higher thermal stress. The increase in thickness has a direct impact on the heat transfer rate as with more thickness the heat transfer will be slow, significantly decreasing the efficiency of the system. Also, the development of concrete having a lower thermal expansion coefficient will significantly increase the system efficiency.