Seismic analysis of arch dams using anisotropic damage-plastic model for concrete with coupled adhesive-frictional joints response

Abstract

Abstract A finite element model for seismic analysis of concrete arch dams is proposed. Material inelasticity as well as joints nonlinearity is considered. A damage-plastic formulation governs nonlinear behavior of concrete. Degeneration occurring during nonlinear behavior of concrete induces anisotropy into its microstructure. This anisotropy becomes more complex in seismic simulations, in which the state of stress expeditiously changes with time. Thus, anisotropic formulation is preferred over classical isotropic models. Utilizing rate-dependent anisotropic damage-plastic model, irreversible deformations, stiffness degeneration, induced anisotropy, closing/reopening of cracks, and viscous response of concrete are attained. Non-penetration condition, frictional behavior, and adhesion resulted by grouting of contraction and peripheral joints are also modeled in a coupled and rate-dependent manner. Different combinations of material and joints nonlinearities are used to model a system of dam-foundation-reservoir. The system is excited using three components of an earthquake, and effect of different sources of nonlinearities is investigated through comparison between results. In addition, capability of the anisotropic damage-plastic model is compared against an available isotropic formulation. A sensitivity analysis is also performed to investigate the effect of properties of joints on responses. Owing to high convergence rate of material and joints constitutive models, implicit time integration is employed, which leads to stable and accurate solutions.