Description |
Earthquake Analysis of Concrete Gravity Dams Including Base Sliding. EAGD-SLIDE evaluates the earthquake response of concrete gravity dams, including sliding at the interface between the base of the dam and the foundation rock surface. The earthquake response of the dam is influenced by the interaction between the dam and the compressible water in the reservoir, by the interaction between the dam and foundation rock, and by the dam-foundation rock interface properties. The dam monolith is modeled by a finite element discretization with linear, elastic, orthotropic material behavior. The water in the reservoir is modeled as a continuum, and the hydrodynamic effects of the impounded reservoir are modeled by the two-dimensional wave equation. The effect of reservoir bottom materials is accounted for by the wave reflection coefficient. The foundation rock is modeled as a linear viscoelastic half-space. A friction model based on the Mohr-Coulomb law is used to approximate the force-displacement relationship at the interface. Base sliding is the only source of nonlinearity in the system. Rocking (or rigid body tipping) is not considered. Other nonlinearities, such as concrete cracking, opening and sliding of joints, and water cavitation are not represented in the model. The system is subjected to horizontal and vertical components of free-field earthquake ground motion acting at the base of the dam. The analysis method uses the hybrid frequency-time domain procedure, which accounts for the nonlinear base sliding behavior of the dam and the frequency-dependent response of the impounded water and the flexible foundation rock, to solve the equations of motion. The program can be used to obtain stresses, displacements, and base sliding of gravity dams subjected to free-field ground motion. |