Study On Complicated Rock Slopes Of Static And Dynamic Stability

Baihetan dam is located at the gorge which is 1.6km long between the Dazai and the Tishuo bridge, and the river flows through the dam site from the south to the north. The low-angle intraformational bed and high-angle relief cracks are distributed in the high left rock slop on No.1 dam axis. Under the action of gravity, seism and seepage, the static and dynamic stability of the slop is very important to the operation safety of the dam.Because of the serious consequences caused by slope failure, the study of stability against sliding is concerned by lots of domestic and foreign experts. The constitutive model which simulates the mechanical characteristic of complicated rock is analyzed in this paper. The essential principle of the plastic mechanics in geotechnical materials about yield criterion, loading—unloading criterion, plastic potential theory and hardening rules is expatiated and applied to the study on stress and stability of complicated rock slopes. Lagrangian multiplier method, penalty function method and modified Lagrangian multiplier applied to solve the dynamic contact problem are discussed. The dynamic friction and contact condition, constitutive equation and FEM combined with Lagrangian multiplier and penalty function are introduced. The constitutive model of anisotropy material is presented. The Hill criterion and associated flow rule are applied to the dynamic analysis on the rock mass with high-angle relief crack and week seam.Based on the theory and method mentioned above, the static calculation for the rock slope of Baihetan project is carried out, and the sensitive analysis is made on the influence of the depth and the connection rate of the high-angle relief cracks to the stress and stability of the slope. With nonlinear finite element method based on the dynamic frictional contact theory and the anisotropic material constitutive model, the stability of the slope under the action of seism is studied. Furthermore, the static and dynamic stability of the slope is also studied under the different kinds of seepage condition. According to the analysis results, the stability of the slope under the action of gravity, seism and seepage is generally evaluated.