Nonlinear seismic response of concrete gravity dams due to foundation fault movement

Not only should dams be evaluated for seismic shaking, but their capability to survive potential fault displacement in their foundations should also be assessed. Safety reviews of existing dams suggest that geological-seismic evaluation of some dam sites has failed to recognize the existence of possibly active faults. In this study, the nonlinear seismic behavior of concrete gravity dams, due to relative fault dislocation occurring in foundations, has been investigated. Two types of fault movement, including normal-slip and reverse-slip, have been considered. These two types, combined with the location of fault lines, with respect to the toe, middle, and heel of the dam base, angle of fault, and water elevation in reservoirs, which result in 36 types of model, have been considered. Results show that each type of fault can cause propagation of specic crack patterns, and the angle and location of the fault beneath the dam have a great eect on the amount of damage induced. The water pressure of the reservoir can also have increasing or even decreasing eects on the crack propagation rate. The existence of foundation fault movement beneath concrete gravity dams, depending on the condition of the problem, can cause rapid crack propagation in the dam body, jeopardize stability, and signicantly change the damʹs dynamic response.