EVALUATION OF GLOBAL SAFETY DEGREE OF JINPING HIGH ARCH DAM
锦屏高拱坝整体安全度评估

Jinping High Arch Dam is the highest double-curvature thin arch dam in the world at present.The water pressure is huge,and the design is beyond the present criterion.The asymmetric characteristics of Jinping High Arch Dam include the landform of two banks,the geological conditions of two banks and the sunlight time of dam surface.For the asymmetries and high water pressure,the safety of Jinping High Arch Dam is one of key issues in the design and construction of Jinping High Arch Dam.With 3D nonlinear finite element method,the stress field and displacement field of Jinping High Arch Dam under some working conditions are studied;and the effects of the geologic formation of two banks on working behavior of arch dam are investigated.The stresses and displacements of dam body are apparently asymmetric for the left and the right banks.The reasons of the asymmetry are not only the asymmetric stiffness of two banks of foundation,but also the asymmetry of dam shape.So the shape of arch dam should be further optimized.The global safety degree(GSD) of Jinping High Arch Dam for natural foundation is studied under different failure modes:GSD that caused by upstream overloading water pressure is about 5.0;GSD that caused by shear strength reduction of rock in dam foundation is about 3.0;GSD that caused by earthquake is about 6.0.According to the distribution of failure zone,the important parts of reinforcing treatment are proposed,i.e.the part above elevation 1 800 m of downstream side of the left arch and that between the elevation 1 630 m and elevation 1 800 m of upstream side of the right arch end.