A Limit Solution for Predicting Side Resistance on Rock-Socketed Piles

Abstract

The mobilization of side resistance of rock-socketed pile strongly depends on the shear behavior of the pile-rock interface. In this study, an asperity-based model was developed to investigate essential responses of interface shear, where asperities develop from sliding with interface dilation to residual shear under the condition of constant normal stiffness (CNS). The emphasis was on quantifying the magnitude of interface dilation in terms of limit analysis solutions. Followed by the proposed upper bound (UB) and lower bound (LB) solutions for asperity collapse loads, the mean value was chosen for approaching the potential exact solution. Laboratory experiments of direct shear tests under CNS conditions were also carried out by the authors, and observations were regarded as evidence that the proposed modeling provided a rational explanation of shear behavior for a pile-rock interface. Parametric studies indicated that two key factors, roughness and material properties, significantly impact the mobilization of ultimate side resistance.