Numerical Simulation of Piles in a Liquefied Slope Using a Modified Soil–Pile Interface Model

Abstract

The liquefaction of soil surrounding a pile significantly affects the dynamic interaction between the soil and the pile. In particular, liquefaction of the sloping ground can induce permanent deformation and a bending moment on the pile due to the lateral displacement of the liquefied soil in the downslope direction. However, numerical analysis studies on piles installed in a liquefiable slope have been very limited and have not properly simulated the behavior of the pile. Therefore, a modified soil–pile interface model was proposed, which linearly decreases the interface friction angle with the increase in the excess pore pressure ratio. The proposed model was validated by comparing it with the centrifuge test results of Yoo et al. (2023). Simulation results on the slope crest settlement and the pile-bending moment showed good agreement with the centrifuge test results. A parametric study was conducted by applying the validated model to analyze the effect of slope inclinations and the amplitude of input motions on the slope displacement and the pile moment. The simulation results showed that the slope inclinations affected the area of the sliding mass, causing a larger pile-bending moment with a larger inclination. When the amplitude of the input motion was sufficiently large to trigger the failure of the liquefied slope, the slope displacement and the pile-bending moment did not increase any further.