Study On Stability Of Slope And Mechanisms Of Deformation And Failure Of Embankment

Based on analyzing characteristic of yield and failure criteria of geotechnique, slope stability under complex conditions have been studied in this dissertation. Combined with real engineering, the mechanisms of deformation and failure of embankment (road slope) have been analyzed also. The main work includes the following parts:(1) The basic characteristic of yield and failure criteria associated with slope stability analysis has been investigated. Fore example, the effect of intermediate principle stress on shear strength has been evaluated; The failure surface and relevant shear strength of soil has been studied based on some failure criteria; The characters of parameters of Drucker-Prager failure criterion had been analyzed with mathematic methods.(2) The assumptions, definition of safety factor, precision and limitation of the limit equilibrium slice methods used in slope stability analysis have been explored. And, the sensibility of degree of slope and gravity of soil on slope stability has been analyzed with limit equilibrium slice methods. Furthermore, the practicability of different limit equilibrium slice methods have been contrasted studied with some slope examples.(3) The conveniency and limitations of finite element method used in slope stability analysis have been studied. Based on comparative study of the criteria for evaluation of slope stability in the shear strength reduction FEM, a convenient criterion has been proposed. And, the effect of uncertain conditions on FOS with FEM has been investigated. Furthermore, some slopes have been analyzed comparatively with limit equilibrium slice methods and FEM.(4) Based on the theory of unsaturated soil, seepage and stability of slope with rainfall infiltration have been researched by FEM method. The influence of different value of matric suction and different location of cracks on slope stability has been analyzed. Furthermore, the influence of water-level fluctuation on stability of slope has been presented with FEM.(5) Combined with real engineering, the character of settlement, lateral displacement, excess pore pressure and stability of embankment (road slope) at different phases of construction have been studied. It is found that the lateral settlement at consolidation phase become small than that at construction phase. Furthermore, the mechanism of road embankment reinforced with geotextile and prefabricated vertical drains have been analyzed with nonlinear FEM.