Probabilistic geotechnical analysis of energy piles in granular soils

• A probabilistic approach for geotechnical design of energy piles is developed.
• The effect of thermal loading on geotechnical design of energy piles is studied.
• The adverse effects of thermal loading are explicitly demonstrated.

Energy piles provide clean energy in lieu of non-renewable energy resources such as petroleum and coal. The current geotechnical design of energy piles is merely realized through enlarging the factor of safety. The factor of safety used for energy piles is at least twice that used for traditional piles, which can lead to considerable additional costs and inconsistent levels of safety. Although the performance of existing energy pile technology is satisfactory and recent investigators have significantly advanced the understanding of the load-transfer mechanisms of energy piles, it is still necessary to quantify the uncertainty in the thermal–mechanical analysis and to develop reliability-based designs for energy piles. This paper presents a pioneering probabilistic study on the geotechnical design of energy piles. The critical soil parameters for ultimate limit state (ULS) and serviceability limit state (SLS) are identified through sensitivity study. The point estimate method is adopted to understand the uncertainty propagation and to estimate the probability of ULS failure and the probability of SLS failure. The adverse effects of thermal loading in the geotechnical design of energy piles are explicitly demonstrated through a case study.