Response of large-diameter rock-socketed piles subjected to lateral loads is a critical issue in foundation design for bridges, high-rise buildings, and offshore platforms. Although the p-y curve method is commonly used for pile analysis in soil, its direct application to rock-socketed piles remains challenging due to the significant differences in mechanical properties between rock and soil. This study investigates the initial stiffness and stress distribution around the large-diameter rock-socketed piles under lateral loads. Based on the Serrano method, the Hoek–Brown strength criterion is extended to derive calculation formulas for rock cohesion and internal friction angle considering confining pressure effects. A three-dimensional numerical model was established using FLAC3D to analyze stress distribution, pile displacement, and p-y curves at different depths. Distribution functions for normal stress and shear stress around the pile were developed. Parameter sensitivity analysis reveals that the initial stiffness of p-y curves is primarily influenced by rock deformation modulus and pile diameter, while rock strength parameters and pile length effects are negligible. Empirical formulas for predicting initial stiffness of p-y curves were proposed through regression analysis. These results serve as both a theoretical basis and an engineering reference for the design and analysis of large-diameter rock-socketed piles under lateral loading.
Xu et al. (Sun,) studied this question.