Study on Calculation Model of Anchor Cable Micro Pile Group Considering Elastoplastic Deformation of Soil in Front of Embedded Pile

Anchor cable micro-pile groups are increasingly utilized in small and medium-sized slope treatment and slope emergency rescue engineering. However, existing calculation models rarely consider the plastic deformation of the soil in front of the embedded section of the pile and the continuity of the deformation of the soil on the side of the pile. To address this issue, the characteristics of the anchor cable micro-pile group in strengthening soil slopes are examined, and the micro-pile group is divided into a loaded section and an embedded section based on the location of the potential sliding surface. For the loaded section, the soil between piles is simplified as a horizontal soil spring, which effectively accounts for the transfer of soil force between piles. For the embedded section, the ideal elastic–plastic <italic>p–y</italic> curve is employed to analyze the interaction between the pile and the soil. The prestressed anchor cable at the crown beam is simplified as an elastic support. Its force is transferred to the pile top of the back row of piles and then redistributed to the pile tops of each row of piles by the crown beam. This arrangement achieves the constraint effect on pile top displacement. Finally, based on the Pasternak two-parameter foundation beam method, a calculation model for the anchor cable micro-pile group is established, considering the elastoplastic deformation of soil in front of the embedded pile and the continuity of soil deformation around the pile. The finite difference method is utilized to solve the calculation model, and the horizontal displacement and internal forces of the structure are obtained. The calculation model is utilized to evaluate examples of soil slope reinforcement with micro-pile groups and anchor cable micro-pile groups, respectively. The study results are compared to both experimental and numerical simulation ones to verify the model's rationality. The effects of soil shear stiffness, the number of anchor cables, and pile diameter on the horizontal displacement and internal forces of the micro-pile group are discussed. The research demonstrates that the plastic deformation of the soil before the embedded section of the pile and the continuity of the deformation of the soil on the side of the pile significantly influence the displacement and internal forces of the micro-pile. As the number of anchor cable bundles increases, the maximum positive bending moment and horizontal displacement of the pile body continuously decrease. The goal of controlling pile deformation and internal forces can be achieved by adding anchor cable bundles.