Horizontal Bearing Behavior and Reinforcement Efficiency of Cemented Soil Mixed Reinforced (CSMR) Pile: Model Tests and Numerical Simulations

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.