  Energy piles are gaining increased popularity due to a growing demand for
clean energy. To further advance the understanding of soil-structure
interaction in energy piles, recently-derived analytical solutions have been
implemented to investigate the impact of stratigraphy on the soil-structure
interaction. This was accomplished by comparing the measured and predicted head
displacements, axial strains and stresses in an energy pile embedded in the
actual homogeneous and layered soil profiles, as well as into synthetic
homogeneous soil profiles. The analytical solutions for homogeneous soil
profile captured the smooth experimentally observed response versus depth very
well. In the case of a layered soil profile, the corresponding analytical model
was capable of capturing nuances in trends of axial stress and strain versus
depth at the interface of different layers. The analytical predictions for the
layered profile appear to be slightly less accurate than for the homogenous
profile. The experimental data obtained from the layered profile appear to be a
bit more scattered than those from the homogeneous profile. In the former case,
the interplay of the individual soil layers with the pile occurs while
maintaining the continuity of the pile stress and displacement at the interface
of different layers. The response throughout each layer of the layered profile
is quantitatively different than the corresponding homogeneous response.
Nevertheless, qualitatively the response throughout each layer of the layered
profile is similar to the response of the pile embedded in the corresponding
homogeneous layer.
