Influence of a rigid cap on thermo-mechanical behavior of nonsymmetrical thermally loaded energy pile group in clay

Dingxin Zhang, Chenglong Wang, Abdelmalek Bouazza, Xuanming Ding, Gangqiang Kong

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This paper presents the results of a series of cyclic nonsymmetrical thermally loaded model-scale tests conducted on floating pile groups, with and without a rigid cap in saturated clay. The energy pile in each group was subjected to 10 two-way (heating- cooling) thermal cycles with an amplitude of 15 ◦C to investigate the potential effects of a rigid cap on the thermomechanical behavior of energy pile groups. It was found that the rigid cap restrained the expansion/contraction of the energy pile in response to temperature change and reduced its irreversible settlement, resulting in a lower differential settlement between the energy and nonenergy piles. Consequently, a lower tilting was observed in the pile group with a rigid cap. In addition, the thermally induced axial load was significantly increased (especially in cooling mode) due to the restriction of a rigid cap. The thermomechanical load transfer profile of the energy pile was also affected by it, resulting in the downward transmission of shaft resistance.

Original languageEnglish
Pages (from-to)654-668
Number of pages15
JournalCanadian Geotechnical Journal
Issue number5
Publication statusPublished - 22 Feb 2023


  • clay
  • energy pile
  • pile group
  • rigid pile cap
  • thermo-mechanical responses

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