Seismic Deformation Analysis of an Earth Dam - a Comparison Study between Equivalent-linear and Nonlinear Effective-stress Approaches

Equivalent-linear analysis of earth dams with QUAD4 is a state-of-practice approach which incorporates a cumulative level of knowledge in soil dynamics that is still used today in many organizations. Nevertheless, today’s availability of more advanced nonlinear effective-stress analysis tools has improved significantly our estimates of shaking-induced permanent deformations of earth structures. In order to better understand the difference between, and facilitate a direct comparison of, the two different analysis methods, we analyzed an earth dam using both the equivalent-linear and the nonlinear effective-stress approach with the commercial finite difference code FLAC by focusing on computed shaking-induced cyclic shear stresses and permanent deformations.