Seismic damage analysis of concrete gravity dams including dam-foundation-reservoir interaction

In this study, nonlinear dynamic analyses of concrete gravity dams which subjected to earthquake ground motion were investigated by considering dam-reservoir and dam-foundation interactions. An anisotropic damage model which include strain softening behavior was firstly presented. Eulerian approach was used for dam-reservoir and dam-foundation interactions. This formulation were included fluid compressibility, effect of the fluid free surface waves, radiation boundary condition and wave damping effect of base absorption. Sommerfeld radiation boundary condition was applied at truncated boundary of the reservoir finite element mesh. Wave damping properties of the reservoir base was considered with condition of one dimensional wave propagation. Foundation domain was modelled as linearly elastic and Unifield boundary condition was used at truncated surfaces of the finite element mesh. Koyna gravity dam was selected for the solutions and dynamic damage analyses of the dam which consider dam-reservoir and dam foundation interactions were obtained. Acceleration records of 11 December 1967 Koyna earthquake were used for dynamic effect. Effects on damage response of the dam, subject to seismic quake were investigated according to variation of foundation elasticity modulus, effect of fluid compressibility and variation of base absorption coefficient. Displacements and damage evaluations were used for assessment of the results.