Energy pile skin friction at interface in clays under temperature cycles

Abstract

In energy geostructures, the long-term shaft resistance is affected by cyclic thermo-mechanical loads associated with structural loads and cyclic thermal solicitations. This study aims to investigate the effect of monotonic and cyclic thermal loads on normally consolidated (NC) and overconsolidated (OC) kaolin clay–rough steel interface. The peak shear stress of interface increased with temperature while the critical state shear strength remained unchanged. For cyclic temperature tests, with applying ten temperature cycles (5–60°C) to NC kaolin–clay interface, significant thermal contraction was observed but the shear strength increased as much as one single heating test. NC interface contracted on heating whereas OC samples dilated. These results highlighted the impact of thermal cycles on clayey interface which was stress history dependent.