Seismic Deformation Analysis of Embankment Dams Using Simplified Total-Stress Approach

In earthquake-prone areas, risk analyses of seismic potential failure modes for embankment dams are often required. In order to evaluate these potential failure modes, seismically induced deformations are needed. The use of numerical modeling to determine embankment dam deformations has gained wide attention in practice, especially when involving liquefiable soils. This study presents a validation assessment of a finite-difference computer program using embankment dam prototypes tested in dynamic centrifuges. Similar to the total-stress analysis methodology, undrained shear strengths were used to characterize seismic behaviors of the embankment soils. As a simplified approach, uncoupled modeling with a primitive constitutive model was adopted. Quasi-steady-state strengths were determined from the laboratory stress-strain curves for the dilative soils tested in the centrifuges. Calculated results were found to be comparable with the measured data from the centrifuge experiments, which provides some level of confidence in the predictive capability of the finite-difference computer program. In particular, a good correlation was observed between the $v_{\max }/a_{\max }$ ratio of the seismic input motions and the calculated settlements.