Damage Index Evaluation of Concrete Gravity Dam Based on Hysteresis Behavior and Stiffness Degradation Under Cyclic Loading

An assessment of seismic vulnerability of concrete gravity dams based on the fragility curves needs a well-defined damage index (DI) to define different states of damage. The DI formulation for other types of structures is not applicable to concrete gravity dams due to the change in failure mechanism. In this study, a definition of DI based on the factor of safety against sliding is attempted and correlated with the DI formulation based on the natural period of the structure and the maximum crest displacement with cumulative energy dissipation. The proposed DI relies on the nonlinear behavior of the concrete gravity dam model under cyclic testing. The hysteresis behavior is also verified through the finite element analysis by considering the damaged plasticity behavior of concrete.