Numerical simulation of centrifuge tests for seismic response of liquefied slopes

Abstract

Seismic loading can cause soil liquefaction, which results in weakened soil strength and stiffness, leading to significant horizontal displacement of soil and damage to structures. The liquefaction-induced lateral spread has been extensively studied through various approaches, including field case analyses and both physical and numerical modeling. However, the studies have typically been conducted on gentle slopes or backfill of quay walls. Nonetheless, foundations of waterfront structures are often located in finite slopes with relatively high inclination angles. Therefore, this study conducted a numerical analysis simulating centrifuge model tests on the liquefaction of relatively steep slopes using the FLAC 2D program. The centrifuge models of liquefiable sand with slopes of 15° and 27° were subjected to ramped sinusoidal base motion with peak amplitudes of 0.2 g. The liquefiable slope, soil container, and interface between the soil and container were modeled in the numerical simulation, and the simulation results were validated with experimental results such as excess pore pressure, acceleration, and settlement behind the crest. Based on the numerical analysis results, the mechanism of slope liquefaction and corresponding horizontal soil displacement due to liquefaction were discussed.