Fracture Response of Gravity Dams due to Rise of Reservoir Elevation

Abstract

A rotating smeared-crack finite-element model based on the energy conservation principle has been considered to predict the static fracture behavior of concrete gravity dams. Water penetration and uplift pressure inside the smeared crack bands have been modeled using the effective-porosity concept. The classical load-control technique and an indirect displacement-control algorithm have been considered in the nonlinear finite-element analyses, with an incremental rise of the reservoir water level. The consideration of water pressure inside cracks has been found to reduce the ultimate resistance of the structure significantly. Structural responses predicted using the traditional “no-tension” gravity method and the finite-element technique are compared to identify the advantages of applying the finite-element method in a practical dam-safety evaluation. The gravity-method analysis of concrete dams may not always provide a conservative response. Sate-of-the-art fracture-analysis models should be considered with a nonlinear incremental structural-analysis technique to evaluate the safety margin of concrete gravity dams against an inflow-design flood.