Investigation of horizontal resistance behavior of vertical-inclined combined high-strength high-pressure jet grouting pile under lateral load

Hand-dug piles are insufficient to meet the load-bearing requirements for transmission tower foundations in the extreme environments of the mountainous regions of Western China. Excessive deformation can not only compromise the stability of the support system but also inflict damage on adjacent structures. The application of vertical-inclined combined high-strength high-pressure jet grouting pile (VICP) in such scenarios can effectively enhance bearing performance; however, their mechanical behavior remains insufficiently investigated. In this study, model experiments are conducted to examine the variations in bending moment, axial force, lateral friction resistance, and shear force in VICP with different inclination angles (α = 90°, 80°, 70°, and 60°) under horizontal loading. The results revealed that: (1) The displacement at the pile top, along with the bending moment, shear force, and axial force, increases progressively as the inclination angle (α) increases. Horizontal bearing capacity decreases with increasing α and L/D ratio. The horizontal bearing capacity of the VICP (α = 60°) is 1.83 times that of the vertical pile configuration. (2) The damage mode of pile foundation involves tensile damage to the left pile and the central pile, with compressive damage occurring in the right pile. (3) The ‘arching effect’ is observed in VICP (α = 80°, 70°, and 60°) compared to vertical piles. As the inclination angle (α) decreases, the arching effect becomes more pronounced.