Chapter 16 – Experimental and Numerical Investigations of the Behavior of a Heat Exchanger Pile

The geothermal use of concrete geostructures (piles, walls, and slabs) is an environmentally friendly way of cooling and heating buildings. With such geothermal structures, it is possible to transfer energy from the ground to fluid-filled pipes cast in concrete and then to building environments. To improve the knowledge in the field of geothermal structures, the behavior of a pile subjected to thermo-mechanical loads was studied in situ. The aim was to quantify the thermal influence on the bearing capacity of heat exchanger piles. The thermal increment applied to the pile was on the order of 21 °C, and the mechanical load reached 1300 kN. Coupled multiphysical finite element modeling was carried out to simulate the observed experimental results. It is shown that the numerical model is able to reproduce the most significant thermo-mechanical effects.