Thermal-mechanical Behavior of a Multiple-loop Geothermal Heat Exchanger Pile
Abstract
Geothermal heat exchanger pile (GHX-pile) is an innovative technique of utilizing heat energy stored in the Earth. However, the technique lacks standard design guidelines considering the behavior of the pile with thermal and mechanical load. Most of the studies done till date focus on the heat exchange behavior of small size piles with only single or double loops. There is a lack of knowledge on the geotechnical aspect of GHX-piles system with multiple loop large-diameter bored piles which are more common in larger structures. Therefore, the current study focuses on the investigating thermal-mechanical behavior of a full-scale GHX-pile. The GHX-pile was thermally loaded by conducting a thermal response test. A modified t-z model was developed and applied to simulate the test result. Parametric analysis was performed with the modified t-z model and combined effect of thermal and mechanical loads on the GHX-pile was investigated. The research results indicated that the heating load increases the axial force mobilization in the GHX-pile. However, in case of loaded pile the change in the mechanical response of the GHX-pile due to thermal load is small. Parametric study showed that the heating load helps to reduce the top displacement, while the cooling load increases the top displacement.
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- OSU Theses [15752]