Abstract
A geothermal energy pile is a revolutionary piling technique that combines a pile foundation with a ground source heat pump system that not only supports the structure but also provides heating and cooling for buildings and bridges. The thermo-mechanical behavior of long energy piles in soft clay has rarely been investigated, despite their increasing utilization. A long floating energy pile with a length-to-diameter ratio of 66.7 was evaluated on its own and monitored in service of the supported structure in the city of Kunshan, China. With vertical mechanical loads, the experiment involved alternate cooling and heating cycles, allowing for careful analysis and assessment of the pile’s temperature, stress, and displacement. Temperature-induced stress, axial force, and friction resistance of the pile shaft, as well as the change in displacement of the energy pile throughout building, were all studied. The field observations revealed without any surprise that a longer energy pile outperformed a shorter one in terms of heating exchange capacity with a more homogenous temperature distribution along the pile. Following a quasi-linear relationship with the temperature variation, the thermo-induced additional axial force soared with the larger length-diameter ratio of the pile and may even reach four times that of the pile under pure mechanical loads. Important additional settlements were also observed especially in cooling conditions. The shaft frictions along the long bored energy pile were found to have a complicated distribution, which requires further investigations.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Abas N, Kalair A, Khan N (2015) Review of fossil fuels and future energy technologies. Futures 69:3149, DOI: https://doi.org/10.1016/j.futures.2015.03.003
Amatya BL, Soga K, Bourne-Webb PJ, Amis T, Laloui L (2012) Thermo-mechanical behaviour of energy piles. Géotechnique 62(6):503–519, DOI: https://doi.org/10.1680/geot.10.P.116
Bolük G, Mert M (2014) Fossil & renewable energy consumption, GHGs (greenhouse gases) and economic growth: Evidence from a panel of EU (European Union) countries. Energy 74:439–446, DOI: https://doi.org/10.1016/j.energy.2014.07.008
Bourne-Webb PJ, Amatya B, Soga K, Amis T, Davidson C, Payne P (2009) Energy pile test at lambeth college, London: Geotechnical and thermodynamic aspects of pile response to heat cycles. Geotechnique 59(3):237–248, DOI: https://doi.org/10.1680/geot.2009.59.3.237
Brandl H (2006) Energy foundations and other thermo-active ground structures. Geotechnique 56(2):81–122, DOI: https://doi.org/10.1680/geot.2006.56.2.81
Brettmann T, Amis T (2011) Thermal conductivity evaluation of a pile group using geothermal energy piles. Geo-Frontiers 2011: Advances in Geotechnical Engineering 499–508, DOI: https://doi.org/10.1061/41165(397)52
Chen DM (2016) Soil structure interaction in energy piles. PhD Thesis, University of California, San Diego, CA, USA
De Moel M, Bach PM, Bouazza A, Singh RM, Sun JO (2010) Technological advances and applications of geothermal energy pile foundations and their feasibility in Australia. Renewable and Sustainable Energy Reviews 14(9):2683–2696, DOI: https://doi.org/10.1016/j.rser.2010.07.027
Faizal M, Bouazza A, Haberfield C, McCartney JS (2018) Axial and radial thermal responses of a field-scale energy pile under monotonic and cyclic temperature changes. Journal of Geotechnical and Geoenvironmental Engineering 144(10):04018072, DOI: https://doi.org/10.1061/(asce)gt.1943-5606.0001952
Gao J, Zhang X, Liu J, Li KS, Yang J (2008) Thermal performance and ground temperature of vertical pile-foundation heat exchangers: A case study. Applied Thermal Engineering 28(17–18):2295–2304, DOI: https://doi.org/10.1016/j.applthermaleng.2008.01.013
Gawecka KA, Taborda DMG, Potts DM, Cui WJ, Zdravkovic L, Kasri MSH (2017) Numerical modelling of thermo-active piles in London Clay. Proceedings of the Institution of Civil Engineers-Geotechnical Engineering 170(3):201–219, DOI: https://doi.org/10.1680/jgeen.16.00096
GSHPA (2012) Thermal pile design, installation & materials standards. Ground Source Heat Pump Association, http://www.gshp.org.uk/GSHPA_Thermal_Pile_Standard.html
Gui S, Cheng X (2014) In-situ test for structural responses of energy pile to heat exchanging process. Chinese Journal of Geotechnical Engineering 36(6):1087–1094, DOI: https://doi.org/10.11779/CJGE201406014 (in Chinese)
Hamada Y, Saitoh H, Nakamura M, Kubota H, Ochifuji K (2007) Field performance of an energy pile system for space heating. Energy and Buildings 39(5):517–524, DOI: https://doi.org/10.1016/j.enbuild.2006.09.006
Jalaluddin AM, Tsubaki K, Inoue S, Yoshida K (2011) Experimental study of several types of ground heat exchanger using a steel pile foundation. Renew Energy 36:764–771, DOI: https://doi.org/10.1016/j.renene.2010.08.011
Kalanditou A, Tang AM, Pereira JM, Hassen G (2012) Preliminary study on the mechanical behaviour of heat exchanger pile in physical mode. Géotechnique 62(11):1047–1051, DOI: https://doi.org/10.1680/geot.11.T.013
Knellwolf C, Peron H, Laloui L (2011) Geotechnical analysis of heat exchanger piles. Journal of Geotechnical and Geoenvironmental Engineering 137(10):890–902, DOI: https://doi.org/10.1061/(asce)gt.1943-5606.0000513
Kramer C (2013) An experimental investigation on performance of a model geothermal pile in sand. PhD Thesis, Pennsylvania State University, Pennsylvania, USA
Laloui L, Nuth M, Vulliet L (2006) Experimental and numerical investigations of the behaviour of a heat exchanger pile. International Journal for Numerical and Analytical Methods in Geomechanics 30(8):763–781, DOI: https://doi.org/10.1002/nag.499
Loria AFR, Gunawan A, Shi C, Laloui L, Ng CWW (2015) Numerical modelling of energy piles in saturated sand subjected to thermo-mechanical loads. Geomechanics for Energy and the Environment 1:1–15, DOI: https://doi.org/10.1016/j.gete.2015.03.002
Loveridge F, Powrie W (2012) Pile heat exchangers: Thermal behaviour and interactions. Proceedings of the Institution of Civil Engineers-Geotechnical Engineering 166(2):178–196, DOI: https://doi.org/10.1680/geng.11.00042
Lu HW, Jiang G, Wang H, Shi CL, Gong HW, Liu WQ (2017) In situ tests and analysis of mechanical-thermo bearing characteristic of drilled friction geothermal energy pile. Chinese Journal of Geotechnical Engineering 39(2):334–342, DOI: https://doi.org/10.11779/CJGE201702018 (in Chinese)
McCartney JS, Murphy KD (2012) Strain distributions in full-scale energy foundations (DFI Young Professor Paper Competition 2012). DFI Journal-The Journal of the Deep Foundations Institute 6(2):26–38, DOI: https://doi.org/10.1179/dfi.2012.008
McCartney JS, Rosenberg JE (2011) Impact of heat exchange on side shear in thermo-active foundations. Geo-Frontiers 2011: Advances in Geotechnical Engineering 488–498, DOI: https://doi.org/10.1061/41165(397)51
Ozudogru T, Brettmann T, Olgun G, Martin J, Senol A (2012) Thermal conductivity testing of energy piles: Field testing and numerical modeling. Proceedings of the GeoCongress March 25–29, Oakland, CA, USA
Preene M, Powrie W (2009) Ground energy systems: From analysis to geotechnical design. Geotechnique 59(3):261–271, DOI: https://doi.org/10.1680/geot.2009.59.3.261
Sørensen B (2010) Renewable energy: Physics, engineering, environmental impacts, economics and planning. Academic Press
Sugiawan Y, Managi S (2019) New evidence of energy-growth nexus from inclusive wealth. Renewable and Sustainable Energy Reviews 103:40–48, DOI: https://doi.org/10.1016/j.rser.2018.12.044
Wang B, Bouazza A, Singh RM, Haberfield C, Barry-Macaulay D, Baycan S (2015) Posttemperature effects on shaft capacity of a full-scale geothermal energy pile. Journal of Geotechnical and Geoenvironmental Engineering 141(4):04014125, DOI: https://doi.org/10.1061/(asce)gt.1943-5606.0001266
Wood CJ, Liu H, Riffat SB (2009) Use of energy piles in a residential building, and effects on ground temperature and heat pump efficiency. Géotechnique 59(3):287–290, DOI: https://doi.org/10.1680/geot.2009.59.3.287
Xiao SG, Suleiman MT, Naito CJ, Neti S (2013) Use of geothermal deep foundations for bridge deicing. Transportation Research Record 2363:56–65, DOI: https://doi.org/10.3141/2363-07
Zou C, Zhao Q, Zhang G, Xiong B (2016) Energy revolution: From a fossil energy era to a new energy era. Natural Gas Industry B 3(1):1–11, DOI: https://doi.org/10.1016/j.ngib.2016.02.001
Acknowledgments
The authors acknowledge financial support provided by The Natural Science Foundation of the Jiangsu Higher Education Institutions of China (Grant No. 21KJB560010), Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering (Grant No. YT202003), Jiangsu Province Science Foundation of China (Grant No. BK20171468), and Water Conservancy Science and Technology Project of Jiangsu Province (Grant No. 2020045) from Water Resources Department of Jiangsu Province, China. The computational resources generously provided by the High Performance Computing Center of Nanjing Tech University are greatly appreciated.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Jiang, G., Shao, D., Zong, C. et al. Thermo-Mechanical Behavior of Long-Bored Energy Pile: A Full-Scale Field Investigation. KSCE J Civ Eng 27, 145–155 (2023). https://doi.org/10.1007/s12205-022-0588-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12205-022-0588-1