A Comparative Study of the Seismic Performances and Failure Mechanisms of Slopes Using Dynamic Centrifuge Modeling

In this study, dynamic centrifuge model tests were performed for sand slopes under different earthquake ground motions and slope angle to characterize the seismic performance of slopes. Four groups of tests under varying seismic input amplitude were conducted. Under the action of increasing earthquake intensity, the rigidity of the soil decreases and the damping ratio increases, both of the dynamic response and the predominant period of slopes are increased. Three types of seismic waves with the same seismic intensity were applied in the model tests. It shows that the variability in the ground motion leads to the acceleration response spectra of the slopes being completely different and the Northridge seismic wave with low-frequency component is closest to the predominant period of the slope model. In addition, the effect of slope angle on the seismic performance of slopes were also clarified. The results reveal how the slope angle affects the acceleration recorded on the ground surface of the slope, both in terms of the peak ground-motion acceleration (PGA) amplification factor and the predominant period. Finally, the permanent displacement of the model slopes under different earthquake intensities were further analyzed. Based on the nonlinear growth of the permanent displacement of the slope, the test results demonstrated the failure process of the slope, which can further provide a basis for theperformance-based seismic design of slopes.