Abstract
An energy pile induces heat exchange with the ground formation by circulating heat carrier fluid through a heat exchange pipe, which is encased in pile foundation. During heat exchange, temperature variation in energy pile generates thermally-induced stress due to the different thermo-mechanical behavior between the pile and surrounding ground, and the restriction of pile deformation. A series of full-scale field tests was performed to identify the thermo-mechanical behavior of a cast-in-place energy pile equipped with 5-pair-parallel U-type heat exchange pipe. During the field investigation, each cooling and heating test lasted for 30 days, including a 15-day operating period and 15-day resting period, and the thermal stress generated in the energy pile was monitored. The maximum thermal stress was evaluated to be 2.6 MPa in the cooling test, which is about 10% of the design compressive strength of concrete. In addition, a finite element (FE) numerical model was developed to simulate the thermo-mechanical behavior of the energy pile. In the numerical analysis, relevant boundary conditions and interface model were determined by comparing with the field measurement. Finally, a parametric study was performed to estimate the thermal stress and deformation of a cast-in-place energy pile for various ground conditions.
| Original language | English |
|---|---|
| Pages (from-to) | 920-938 |
| Number of pages | 19 |
| Journal | Energy |
| Volume | 161 |
| DOIs | |
| Publication status | Published - 2018 Oct 15 |
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Keywords
- Cast-in-place energy pile
- Ground heat exchanger
- Numerical analysis
- Thermal stress
- Thermo-mechanical coupled analysis
ASJC Scopus subject areas
- Civil and Structural Engineering
- Building and Construction
- Pollution
- Mechanical Engineering
- Industrial and Manufacturing Engineering
- Electrical and Electronic Engineering
Cite this
Thermo-mechanical behavior of cast-in-place energy piles. / Sung, Chihun; Park, Sangwoo; Lee, Seokjae; Oh, Kwanggeun; Choi, Hangseok.
In: Energy, Vol. 161, 15.10.2018, p. 920-938.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Thermo-mechanical behavior of cast-in-place energy piles
AU - Sung, Chihun
AU - Park, Sangwoo
AU - Lee, Seokjae
AU - Oh, Kwanggeun
AU - Choi, Hangseok
PY - 2018/10/15
Y1 - 2018/10/15
N2 - An energy pile induces heat exchange with the ground formation by circulating heat carrier fluid through a heat exchange pipe, which is encased in pile foundation. During heat exchange, temperature variation in energy pile generates thermally-induced stress due to the different thermo-mechanical behavior between the pile and surrounding ground, and the restriction of pile deformation. A series of full-scale field tests was performed to identify the thermo-mechanical behavior of a cast-in-place energy pile equipped with 5-pair-parallel U-type heat exchange pipe. During the field investigation, each cooling and heating test lasted for 30 days, including a 15-day operating period and 15-day resting period, and the thermal stress generated in the energy pile was monitored. The maximum thermal stress was evaluated to be 2.6 MPa in the cooling test, which is about 10% of the design compressive strength of concrete. In addition, a finite element (FE) numerical model was developed to simulate the thermo-mechanical behavior of the energy pile. In the numerical analysis, relevant boundary conditions and interface model were determined by comparing with the field measurement. Finally, a parametric study was performed to estimate the thermal stress and deformation of a cast-in-place energy pile for various ground conditions.
AB - An energy pile induces heat exchange with the ground formation by circulating heat carrier fluid through a heat exchange pipe, which is encased in pile foundation. During heat exchange, temperature variation in energy pile generates thermally-induced stress due to the different thermo-mechanical behavior between the pile and surrounding ground, and the restriction of pile deformation. A series of full-scale field tests was performed to identify the thermo-mechanical behavior of a cast-in-place energy pile equipped with 5-pair-parallel U-type heat exchange pipe. During the field investigation, each cooling and heating test lasted for 30 days, including a 15-day operating period and 15-day resting period, and the thermal stress generated in the energy pile was monitored. The maximum thermal stress was evaluated to be 2.6 MPa in the cooling test, which is about 10% of the design compressive strength of concrete. In addition, a finite element (FE) numerical model was developed to simulate the thermo-mechanical behavior of the energy pile. In the numerical analysis, relevant boundary conditions and interface model were determined by comparing with the field measurement. Finally, a parametric study was performed to estimate the thermal stress and deformation of a cast-in-place energy pile for various ground conditions.
KW - Cast-in-place energy pile
KW - Ground heat exchanger
KW - Numerical analysis
KW - Thermal stress
KW - Thermo-mechanical coupled analysis
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U2 - 10.1016/j.energy.2018.07.079
DO - 10.1016/j.energy.2018.07.079
M3 - Article
VL - 161
SP - 920
EP - 938
JO - Energy
JF - Energy
SN - 0360-5442
ER -