Nonlinear dynamic analysis of a concrete gravity dam considering an elastoplastic constitutive model for the foundation

Dam failure can result in a catastrophic break followed by a ood wave, often with considerable loss of life or property. One of the main causes of dam failure is loss of shear strength and the existence of discontinuity within the foundation. Dynamic analysis of concrete dams usually considered concrete behavior to be nonlinear and the foundation rock is assumed to be linear. In this study, seismic analysis of a concrete gravity dam was conducted to investigate the eect of the foundation on the nonlinear response. A nite element model of a 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. The Mohr-Coulomb model was utilized for the yield and potential functions of the foundation. The dam body was modeled using a smeared crack model. After modeling the dam-reservoir foundation, the horizontal recorded ground acceleration of the 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 the elastoplastic model for the foundation is more realistic, and under dierent boundary conditions, a signicant amount of energy will be dissipated in the foundation.