Nonlinear Dynamic Analysis of Concrete Gravity Dam Considering Elastoplastic Constitutive Model for Foundation

Dam failure can result in a catastrophic break followed by a flood wave often with considerable loss of life or property. One of the main causes of dam failure is loss of shear strength and existence of discontinuity within foundation. Dynamic analysis of concrete dams usually considered concrete behavior to be nonlinear and foundation rock is assumed to be linear. In this study, seismic analysis of concrete gravity dam was conducted to investigate effect of foundation on the nonlinear response. A finite element model of dam-reservoir-foundation was considered to properly model the foundation as well as dam body nonlinear behaviors. An elasto-plastic formulation was used to model the foundation. Mohr-Coulomb model was utilized for the yield and potential functions of the foundation. The dam body modeled by using smeared crack model. After modeling the dam-reservoir foundation, horizontal recorded ground acceleration of Kobe 1995 earthquake was applied to the model and results were studied. It was found that cracks form at the crest and hill of the dam.Using elastoplastic model for the foundation is more realistic and under different boundary conditions a significant amount of energy will be dissipated in the foundation.