Research on the Effect of Foundation Damage on the Dam Heel Stress of Concrete Gravity Dams

Abstract

The key part of the stress analysis for the concrete gravity dam is the dam heel where the stress gradient is high. When doing the stress analysis, usually assuming that the bedrock is a homogeneous isotropic elastic body, it does not match with the reality. In this study, using the isotropic damage model and the nonlinear stress-seepage-damage coupling analysis method, taking spillway section 2 of the Three Gorges Dam as an example, regarding the rock mass and dam concrete as isotropic permeable continuous media, the effects of the foundation seepage, damage and stress-seepage coupling on the dam heel stress are analyzed and the following conclusions are obtained: (1) the seepage force is more appropriate when considering the water pressure on dam basin; (2) considering foundation damage and the stress-seepage-damage coupling, the dam heel stress is released the first principal stress and the vertical stress are decreased significantly. The seepage filed around the dam heel is also changed.