Analytical prediction of displacement-dependent lateral earth pressure against stabilizing piles in sandy slopes considering arching effect

Accurate prediction of the magnitude and distribution of lateral earth pressure is essential for reliable structural design of stabilizing piles. Although there have been many analytical studies of the lateral load response of these piles, they inadequately quantify the pressure distribution under working conditions and primarily neglect the soil arching effect. This study proposes a novel analytical method for displacement-dependent analysis of the lateral earth pressure against piles in sandy slopes by considering soil arching effect. A shear resistance mobilization model was proposed to characterize the relation between the soil displacement and mobilized friction angle of soils. This was then incorporated within the slice element method to solve the profile of sliding wedge between two adjacent piles and the associated active lateral earth pressure. An improved arching model, capable of analyzing the noncircular arch shape, was combined with the active lateral earth pressure to calculate the lateral load transferred on the piles. Comparison of analytical results with experimental and numerical observations demonstrated that the proposed method can reliably predict the progressive development of nonlinear pressure distribution with soil displacement. Neglecting shear resistance mobilization and soil arching effect results in an overestimation of external forces applied to the piles. Meanwhile, parametric studies indicated that surcharge pressure exerts the greatest influence on resultant lateral force, followed by internal friction angle of soils, while slope angle and pile spacing have lower influences. Furthermore, the proposed method allows the capture of the influence of soil displacement profile and spatial arching behavior on the pressure distribution. This study facilitates a performance-based assessment of the lateral load response of piles in slopes, particularly in scenarios with scarce design parameters.