The effect of thermoactivated pile spacing on the thermo-mechanical response of energy soldier piled walls—experimental study and initial numerical observations

Piles used for vertical and lateral support can function as heat exchangers. While there is extensive knowledge on the thermo-mechanical response of axially loaded piles, less is known about laterally loaded piles. Observations show minimal differences between largely spaced thermo-activated piles in piled energy walls and axially loaded piles, with more significant effects reflected in axially thermally induced stress. This study uses experimental and numerical methods to examine the impact of activating multiple piles with different inter-pile spacings on the structural and geotechnical performance of piles in a retaining wall built in sedimentary rocks. Experimental results indicate that activating largely spaced piles is comparable to activating closely spaced piles with a reduced temperature change. Initial numerical results confirm that over the experimental period, the thermally induced structural demands shear forces and bending moments, and lateral displacements remain marginal to their initial mechanically induced demands, while remaining within the design limits for the case study.