Research on optimized design of section parameters of special-shaped pile based on square section

Pile foundations are widely utilized in the construction of high-rise building foundations; however, traditional square piles may not be sufficiently economical due to their requirement to resist substantial vertical loads with large dimensions and dense arrangements. This study presents a novel special-shaped pile designed for high-rise buildings, which aims to enhance the ultimate bearing capacity by expanding the contact area between the pile and the soil. Based on pile bearing capacity theory, this study analyzes the effects of the number of concave sides and the angle of concavity on the cross-section properties of the special-shaped pile. Additionally, a finite element model built and validated over ABAQUS is employed to simulate the influence of varying numbers of concave edges and different concave angles on vertical load bearing characteristics. The results indicate that the cross-sectional perimeter of the special-shaped pile increases with the number of concave edges and the angle of concavity, measuring 1.01 to 1.78 times that of a square pile with the same cross-sectional area, with the angle of concavity having the most significant effect. The maximum moment of inertia of the cross-section of the special-shaped pile initially increases and then decreases with the number of concave sides, while it consistently increases with the angle of concavity. Notably, for a given angle of concavity, the maximum moment of inertia is greatest for the special-shaped pile with two concave sides. Increasing the number of concave sides and the angle of concavity effectively enhances the side resistance and ultimate bearing capacity of the pile, with the ultimate bearing capacity being 1.05 to 1.92 times that of a square pile with the same cross-sectional area.