Behaviour analysis on the vertically loaded bored pile socketed into weak rocks using slip-line theory arc failure surface

Due to the advantages of high bearing capacity and small settlement, rock-socketed bored piles have been commonly used as the foundation for most structures. In this paper, for the vertically loaded bored pile socketed into weak rocks, the shear failure process of the concrete-rock interface was divided into two stages, e.g., a dilatant sliding stage and a post-peak sliding stage, and a bilinear shear model was proposed to describe the relationship between shear stress and concrete-rock relative displacement. The shape of the concrete-rock shear failure surface was determined using the dilatancy effect and the slip-line field theory, and the critical shear displacement of the concrete-rock interface was clarified. Load transfer method of the vertically loaded bored pile socketed into weak rocks was then established to capture the distribution of axial force. Moreover, a parameter study was conducted to assess the influence of the concrete-rock interface roughness, normal stiffness, and residual friction angle on the residual skin friction.