Robust design of energy piles using a fuzzy set-based point estimate method

Abstract

Energy piles have been adopted worldwide as a green foundation technology. The current geotechnical design methods for energy piles — factor-of-safety-based design and reliability-based design — mainly focus on the safety and cost, while design robustness is usually ignored. This paper presents a robust design model for energy piles that is based on the load-transfer method. A fuzzy set-based point estimate method is adopted to quantify the uncertainty in the ultimate limit state design and serviceability limit state design. This robust design approach is intrinsically a multi-objective optimization, in which the optimal design can be determined by simultaneously meeting the requirements for safety, cost and robustness. The proposed robust design approach for energy piles is demonstrated through a case study.