Global safety evaluation of RCC arch dam under cracks

Using the model of thin layer element to simulate the radial penetrating cracks of an RCC arch dam,two 3-D with and without cracking FEM models were established according to the geological and mechanical characteristics.Based on the results of nonlinear analysis,according to the distribution of stress and displacement and the yield distribution of dam and foundation when overloading,the influence of crack on the global safety degree of dam-foundation system was evaluated.The research results demonstrate that the calculating results of two different models are almost the same in all conditions.Crack has little influence on the distribution of stress and displacement,but stress concentration occurs at the end of the crack in cracking model,so measures should be taken to prevent the crack from developing.Under overloading,the yield distributions of dam-foundation system of two different models are also similar,the global safety degrees of two models are both 6.0 with elastic dam materials,and 4.0 with elastic-plastic dam materials.The radial penetrating cracks have little influence on the global safety degree of this dam.