In this paper, a new type of composite pile called mud absorption (MA) pile was proposed, which is composed of a precast core pile and the paste slurry. Based on the field static load test and three-dimensional coupled discrete element method-finite difference method (DEM-FDM) simulation, the compressive bearing characteristics and load transfer mechanism of the MA pile were investigated. The results indicate the MA pile is the friction pile with higher bearing capacity. The vertical load on the pile top is jointly borne by the core pile and the paste slurry and transferred to the surrounding soil, forming a composite structure with a stiffness gradual that transitions from strong to medium to weak. By monitoring the displacements of the core pile, paste slurry, and the surrounding soil, it has been demonstrated that the core pile and paste slurry work synergistically. This synergy effectively enlarges the pile radius and enhances the bearing capacity of the pile foundation. The effects of paste slurry properties and the ratio of core pile side length to pile diameter on the bearing capacity were finally investigated, providing assistances for the design and application of MA piles.

Local cemented soil improvement is an effective means of enhancing the horizontal resistance of pile foundations, although the associated redistribution of horizontal loads and the efficiency of cemented soil usage have not yet been fully clarified. This study combines horizontal loading model tests with three-dimensional finite-difference method (FDM) analysis to explore the horizontal bearing mechanism of the monopile and the cemented soil mixed reinforced (CSMR) pile. The effects of cemented soil reinforcement on pile bending moment, pile–soil displacement, and effective horizontal stress were examined using the validated FDM model. The results reveal that cemented soil reinforcement modifies the shallow load-transfer mechanism, reduces the maximum pile bending moment, and enlarges the deformation-affected and effective horizontal stress diffusion ranges in the surrounding shallow soil. Increasing reinforcement width or depth improves the ultimate horizontal bearing capacity, but the corresponding enhancement efficiency decreases with increasing reinforcement dimensions. A volume-based reinforcement efficiency index was further introduced to assess the correlation between bearing performance improvement and cemented soil consumption. These findings provide additional information for evaluating cemented soil reinforcement dimensions from both bearing-performance and material-utilization perspectives.