A framework for understanding energy pile behaviour

A descriptive framework for explaining the contribution of the foundation material and various levels of end-restraint, to the response of piles that are loaded thermomechanically, is presented. This simple, descriptive approach is then verified against the results of two field tests where piles were loaded thermomechanically, and while there is a degree of asymmetry in the real data as a consequence of the natural variation in the surrounding soils, the mechanisms of response seem to be captured. It is considered that this framework will be important as a means for understanding the results from physical and numerical modelling, and as a tool for explaining the mechanisms of response affecting energy foundations to engineers unfamiliar with the technology.