Field tests of the thermal-mechanical characteristics of energy piles during thermal interactions

WANG Yanran; KONG Gangqiang; SHEN Yang; SUN Zhiwen; WANG Xinyue; XIAO Hanyu

doi:10.16511/j.cnki.qhdxxb.2020.21.006

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Journal of Tsinghua University(Science and Technology) ›› 2020, Vol. 60 ›› Issue (9) : 733-739. DOI: 10.16511/j.cnki.qhdxxb.2020.21.006

SPECIAL SECTION: ENERGY GEOSTRUCTURE AND ENGINEERING

Field tests of the thermal-mechanical characteristics of energy piles during thermal interactions

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Abstract

The heat transfer efficiency, induced thermal stresses and energy pile deformation are key problems in energy pile designs. However, there has been little research on the heat transfer efficiencies and thermal-mechanical characteristics of energy piles caused by thermal effects. Field tests using a row of energy piles (1×3) with 3.0 kW heating were conducted to study the thermal-mechanical characteristics of the piles. The temperatures, strains and stresses of the middle and end piles were measured to study the differences with comparisons to a single energy pile with 3.0 kW heating. The results showed the heat transfer efficiencies, thermally induced displacements, thermally induced lateral friction resistances and the neutral point positions of the energy pile. The results show that the heat transfer efficiency of the 1×3 energy row piles is about 93% for these test conditions. The neutral point of the thermally induced lateral friction appears at about 0.4 times the pile length. The displacement of the top of the middle pile is 0.5‰ times the pile diameter (0.28 mm) while that of the edge pile is 0.3‰ times the pile diameter (0.18 mm).

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energy pile / piles in a row / heat transfer efficiency / thermo-mechanical characteristics / field tests

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WANG Yanran, KONG Gangqiang, SHEN Yang, SUN Zhiwen, WANG Xinyue, XIAO Hanyu. Field tests of the thermal-mechanical characteristics of energy piles during thermal interactions[J]. Journal of Tsinghua University(Science and Technology). 2020, 60(9): 733-739 https://doi.org/10.16511/j.cnki.qhdxxb.2020.21.006

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