A physical model study on the thermal resistance of steel energy piles filled with different materials
A physical model study on the thermal resistance of steel energy piles filled with different materials
Geothermal energy piles, when integrated with ground source heat pump systems, offer an efficient solution for building heating and cooling. This study presents preliminary model-test results from an energy pile project implemented for a building in São Paulo, Brazil. In this project, driven steel pipe piles serve as ground heat exchangers, enabling thermal energy transfer between the building and the surrounding soil. To support the selection of an optimal filler material aimed at minimizing pile thermal resistance, laboratory-scale model tests were conducted. Thermal load tests were performed on pile sections equipped with a single U-loop and installed at the center of a circular tank (1.25 m in diameter and 0.67 m in height) filled with either dry or saturated sand. The filler materials tested included sand, concrete, concrete with steel fibers, and water. A steel pile section (0.22 m in diameter and 0.55 m in height) was used to simulate radial heat transfer from a segment of an energy pile. Temperature sensors were installed at various distances from the pile wall to monitor the thermal response of the surrounding sand. This paper presents temperature measurements at the pilesoil interface and in the surrounding soil under thermal loading in saturated sand, reflecting field conditions where the steel pipe energy piles are installed below the groundwater table.
Milena Murari; Cristina De Hollanda Cavalcanti Tsuha
11th International Conference on Physical Modelling in Geotechnics (ICPMG2026)
Session 5: Energy geo-structures and foundation systems
https://doi.org/10.53243/ICPMG2026-106