Experimental behaviour and numerical analysis of energy piles

The use of pile foundations as heat exchangers in combination with heat pump conditioning systems are becoming increasingly popular. This occurs for a number of reasons mainly related to the develop-ments of more efficient and environmentally friendly solutions for the building conditioning. A relatively large number of small scale laboratory tests and field scale experiments are available and useful to get an insight in the mechanism governing pile-soil interaction under thermo-mechanical loading. On the other hand numerical anal-ysis represents a powerful tool to simulate even complex thermo-mechanical tests. In the paper numerical FEM simulations are performed for published experimental investigations. The paper focus is on the load-settlement relationship and on the load-transfer curves with depth for piles subjected to combined mechanical and thermal loadings. A simple procedure to calibrate the stiffness and the strength parameters of the soil model is proposed and validated.