| The geological condition across the whole China is very complex, and the geological disaster stricks from time to time. The disaster caused by slope instability is even more serious. The research of slope stability has become a hot issue in the field of geotechnical engineering. With the rapid development of computer technology, a large number of finite element software were used to analyze the stability of engineering, and also the good practical results are achieved. In the issue of slope stability analysis, the shear reduction finite element method (SSR-FEM) has been widely used to. compared with the conventional slope analysis method. SSR-FEM not only satisfy the force equilibrium condition, but also consider the relationship between stress and strain of material, without any assumptions are required, The minimum safety factor and the corresponding, critical slip surface with any shape can be automatically obtained, while it can also reflect the slope instability and the development of plastic zone.In this thesis, a large scale FE program ABAQUS is adopted to calculate and analyze the various complex slope, and the impact of various factors on the stability of slope are discussed. The main research contents include the following aspects:1. The stability of complex embankment and the settlement of soft ground are respectively discussed.Through using SSR-FEM, the effect of foundation depth, soil layer structure and slope ratio, and the other factors on embankment stability is discussed, the styles of foundation selected are involved in the flat ground, sloping ground and line shape distribution ground; The effect of vehicle load on the slope stability during the operation of embankment is also discussed. For the filling embankment on soft soil ground, some main factors as the aging characteristics of soft soil and Drucker-Prager creep model, is incorpated in the computation using ABAQUS software, and the settlement of embankment and the pressure of pore water in foundation are also discussed.2. The slope stability under the slow drawdown and rapid drawdown is discussed.The two extreme cases of drawdown (slow and rapid) is respectively discussed, the effect of drawdown rate, Parameter ofλand slope angle on safety factor, and the results of the slope stability under the two conditions are compared. The stability charts obtained from the two extreme cases, provide a guidance to the practical project.3. The slope stability under the unsteady seepage and the stability charts method are discussed.Considered the water drawdown of reservoir or river and the unsteady seepage of clay slope, a large program ABAQUS based on shear strength reduction finite element method (SSR-FEM) is developed to compute the safety factor of slope stability, under the action together of surface water and ground water. Comparative analysis and parameters changing are carried out, the effect of soil properties parameters, relative infiltration ratio, boundary condition, the distribution of saturation line etc. on the stability of slope are further discussed. Then, the combination mode of different parameters is considered, the stability charts method is presented to directly obtain the slope stability under water drawdown condition. The suggested method can rapidly obtain the safety factor of existing slope and the design inclination ratio of planning embankment, and can be a helpful supplement for the existing charts of simple slope.
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