Nonlinear dynamic analyses of an earth dam

The following investigations are presented: (1) Comparison between the results of 2D nonlinear and 3D nonlinear dynamic finite element analyses of an earth dam subject to two very different input ground motions; and (2) comparison between measured and computed earthquake responses of the dam. The study is based on rigorous nonlinear hysteretic analyses utilizing a multi-surface plasticity theory. The backbone shear stress-strain curve is assumed hyperbolic and symmetrical about the origin. Detailed comparisons of induced stresses, strains, accelerations, and permanent deformations at various locations in the dam are presented. The effects of three-dimensionality on the dynamic response, particularly on resulting permanent deformations, are assessed. The suitability of 2D analyses in determining the dynamic behavior of such structures is evaluated.