EARTHQUAKE-INDUCED PLASTIC DEFORMATION OF EARTH DAMS.

An efficient and cost effective analytical-numerical technique is proposed for the elasto-plastic 'nonlinear' earthquake response analysis of earth dams. The procedure is applied to the one-, two-, and three-dimensional models of an existing earth dam; computed permanent deformations due to strong ground motions are presented. The technique is based on a Galerkin formulation in which the solution of the equations of motion is expanded using the eigenmodes, of the linearized problem, defined over the whole spatial domain occupied by the dam model(s). Time integration of the resulting semi-discrete, coupled, nonlinear matrix equations is performed using the Newmark family of method along with Newton Raphson-type interactions at each time step to construct the solution. A nonlinear elasto-plastic kinematic multi-yield surface constitutive model for the dam materials is used.