Influence and Bearing Mechanisms of Thorn Shape on Compressive Characteristics of Thorn Piles

A new type of thorn pile is proposed to address the poor bearing capacity of the foundation. The design of five thorn piles is presented, and the numerical simulation of pile–soil interaction under a uniform silt foundation is performed using ABAQUS software. The influence of thorn shape on the compressive bearing capacity of thorn piles is elucidated, and the mechanism of thorn structure on the soil around piles is analyzed. The results showed that the thorn pile can significantly increase pile shaft resistance and reduce pile top settlement compared with the smooth pile. The ultimate bearing capacity of the 5# pile is 1.6 times higher than that of the smooth pile, while the pile top settlement is reduced by 82.9%. The addition of a thorn structure effectively changes the mechanical characteristics of pile shaft resistance softening. Due to the unique characteristic of the divergent conical surface, the truncated conical thorns exert a powerful radial pressure on the surrounding soil under load, thereby increasing the effective stress of the soil around the pile, expanding the influence range of the soil around the pile, and fully mobilizing the shear resistance of the soil, thus improving the bearing capacity of the foundation pile. The optimal shape of the taper thorn is a cone under the same conditions of length and volume. The research results can provide a theoretical foundation for the design and construction of the thorn pile.