Seismic response of asphaltic concrete used as an impermeable core of a rockfill dam was investigated. In the first part of the study, geotechnical parameters of the asphaltic concrete were obtained from a series of monotonic and cyclic triaxial tests. In the second part 2D & 3D Nonlinear numerical analyses were performed for the highest dam with asphalt concrete core in Iran (Shur River Dam) under seismic forces. Different stages of construction and reservoir filing were analyzed using the hyperbolic model with finite difference method. Both 2D & 3D analysis confirms that earthquake shock can lead to developing some cracks and increasing permeability of asphalt in the upper part of the core, also maximum vertical deformations occur near the crest and at the lower part of the upstream slope. The pattern of the core deformation in 2D analysis includes settlements of the shells behind the asphaltic core and the core remains upright but 3D analysis shows that the core can settle with the neighboring shells. Furthermore 2D analysis shows more settlements in the shells and less crest accelerations in comparison with 3D analysis. Shear strains in the asphaltic core have different trends in the two types of analyses.

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