Field investigation on a pilot energy piled retaining wall

This study presents the thermal and thermo-mechanical responses of a pilot energy wall located in Melbourne, Australia, which is believed to be one of the first instrumented energy soldier piled walls in the world. The full-scale field thermal and thermo-mechanical conditions of the wall were monitored during the period of a full-cycle thermal response test (TRT) conducted on a single soldier pile over 2 months. The monitored pile and ground temperature responses reveal the significance of the thermal condition in the excavated space on the thermal performance of such energy geostructures, which increases complexities in design and analysis. Furthermore, this study reports the profiles of axial strains and induced thermal stresses in the tested soldier pile, demonstrating how the applied thermal load from the TRT influenced the mechanical performance of the pile and wall and how the restrictive action of the support elements controlled the induced conditions. Here, we show that soldier pile responds differently from energy piles or borehole heat exchangers; however, residual axial strains were minimal and similar to those reported in energy piles foundations due to a thermo-elastic response to the imposed thermal loads and wall rigidity. Finally, the unique experimental dataset is made available for further studies.