Shaking Table Modeling of Seismically Induced Deformations in Slopes

Physical model experiments were performed on a 1 g shaking table with the principal goals of: (1) investigating the mechanisms of seismically induced permanent deformations in slopes, and (2) assessing the accuracy and applicability of the Newmark sliding block procedure for estimating seismically induced deformations in slopes. Each of the clayey slope models deformed in response to strong shaking, with the principal mode of deformation being deep rotational/translational sliding displacement. Deformations were principally focused along one or more highly localized shear surfaces, though a significant amount of additional deformation was also distributed over a relatively wide region of the models. The Newmark analyses generally provided moderately accurate, although somewhat unconservative, estimates of deformations. Displacements computed using the rigid sliding block analysis ranged from 27 to 225% of maximum measured displacements, and averaged about 75% of measured displacements for the test series. The Newmark-type analyses were most reliable for those model tests that experienced large deformations, where the sliding resistance was controlled principally by postpeak to residual strengths.