Deformation and Load-Bearing Characteristics of Step-Tapered Piles in Clay under Lateral Load

Abstract

The step-tapered pile foundation is a relatively new structure. For this reason, current literature on step-tapered piles is still not systematic or comprehensive. Thus, it is of the utmost importance to carry out tests and theoretical research on the deformation and load-bearing characteristics of step-tapered piles. The research presented in this paper analyzed the deformation and load-bearing characteristics of step-tapered piles under lateral load using physical model tests and theoretical analysis. A total of four model piles were adapted for the test. The tensile and compressive strengths of the piles were measured, and corresponding load and deflection curves were obtained. Meanwhile, a computational program was developed to simulate and model variable cross-section piles. The internal force and displacement curves of piles under lateral stress at different positions of variable cross-section and stress boundary conditions at the pile top were theoretically calculated using this program. The results from the model test and theoretical analysis were compared and showed good consistency. The results indicated that a step-tapered pile is highly effective at resisting lateral loads. It is most effective when the enlarged pile section is between 33.3 and 46.7% of the total pile length.