Geothermal energy piles are categorized as closed systems. Energy piles are a relatively new technology which couples the structural role of traditional pile foundations to that of heat exchangers to fulfill the required energy demand of buildings and infrastructures. These foundations are equipped with pipes embedded in the concrete forming the pile. While connected to a heat pump, the fluid circulating inside these pipes provides the exchange of heat with the ground for heating and cooling purposes. As the undisturbed temperature at the shallower depths of the ground stays comparatively constant the whole year, being warmer than the surrounding temperature in winter and cooler in summer, the capacities of ground thermal storage are beneficial for withstanding the process of cooling and heating. In this study, heat exchange between the pile foundations and rock is investigated. The behavior of such foundation as energy piles, which are governed by their response to thermo-mechanical loads, is presently not fully understood. The influence of different pipe configurations embedded in the pile is examined while the pile is embedded in two different rock types (limestone and sandstone). It has been observed that pipe configurations strongly affect the behavior of the energy piles. An increase in the axial distributions of vertical thermal stresses has been recorded when the pile equipped with double U-pipes is compared with that of the single U-pipe configuration. The maximum value of the axial distributions of the thermal vertical displacements was observed when the pile foundation equipped with double U-pipes was buried in the limestone.

Degree Date

Spring 2019

Document Type


Degree Name



Civil and Environmental Engineering


Usama El Shamy

Subject Area

Civil Engineering

Number of Pages




Creative Commons License

Creative Commons Attribution-Noncommercial 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License