A study of the effects of dam-foundation interaction on the response of earth dams to obliquely incident P and SV waves is presented. The numerical formulation combines the Finite Element Method and the Boundary Equation Method in a powerful hybrid technique. The FEM has been proven very efficient for finite size elastodynamics problems, but several previously suggested modifications for handling infinite domain dynamic problems seem to be either computationally expensive or have serious limitations on the geometry and excitation. The BEM is employed to solve the half space problem using exact Green\u27s functions to compute the half space stiffness, which is then incorporated in the FEM solution. This technique proved to be exceptionally powerful as it leads to accurate and very efficient solutions. A preliminary study is undertaken to investigate the response of dams subjected to obliquely incident P and SV waves, propagating across the dam width. The results of the present rigorous study extend the conclusions from earlier studies on the effects of the dam-foundation interaction and the special variability of the ground motion. Moreover, the proposed model provides an efficient tool for dynamic analysis of earth dams and is part of a broader study of 2D and 3D dams using the hybrid formulation in both the frequency and time domains, with final objective the incorporation, in the latter case, of soil nonlinearity
