The Research Of Some Application Problems In Finite Element Method For Slope Stability Analysis

Stability method based on slip surface FE stress and shear strength reduction method are two principal methods for FEM slope stability analysis. Some research work focusing on FEM in slope stability analysis is displayed in this paper. Based on the summarization of the latest research and development of slope stability analysis method, the author illustrates the principles for the two kinds of finite element methods, compares the differences between the two methods, and does further research work for the application of slope stability FEM, applying the slope stability FEM into embankment slopes and excavation slopes, and evaluating the stability of foundation pit and determining the ultimate bearing capacity of soil mass structure. The specific research work is summarized as follows:(1) Definition of safety factor in slope stability analysis and principles for two different FEMs. The differences of safety factor quantity, slip surface shape and location between stability method based on slip surface FE stress and shear strength reduction method are compared and studied. The author analyzes numerical examples, and D-P yield criterion, which is based on non-associated flow rule and match precisely M-C criterion, is used to analyze the stability of natural slope(homogeneous slope, clay slope with a weak foundation layer, clay slope with a foundation layer including a thin weak layer and stable seepage)under plane strain condition. The results indicate that the safety factor quantity, the corresponding shape of critical slip surface and its location of these two FEMs are very close.(2) The stability analysis of embankment and excavation slope under plane strain condition. Stability method based on slip surface FE stress is used and the results are compared with natural slope, which indicates that the shapes of critical slip surface of the three kinds of slopes are almost the same. Differences of the results of finite element method is compared with that of limit equilibrium method, and the effect of different soil parameter on the stability of embankment and excavation slope is analyzed . And slip surface stress analysis is applied to the slope stability analysis of earth-rock dam.(3) FEM numerical simulation of foundation pits with traditional and compound soil nailing supports under plane strain condition. Stability method based on slip surface FE stress is applied to evaluate the stability of foundation pits and is also used in two engineering practices. The author studies the tensile force of soil nails in the two support structures and the deformation variance of foundation pit and the differences. The influence of different...