Strength Reduction FEM Of Slope Stability Analysis Based On Energy Theory

As compared with the traditional critical equilibrium method,the superiority of the finite element mehtod in slope stability analysis is obvious,because it can analyse the effect of most of the major factors in slope stability analysis.To this day,The finite element method based on the strength reduction technique have been increasingly applied to the numerical analysis of slope stability,however,this method has not been developed in practice.In this thesis, the key issues related to these methods are discussed. The main investigations are composed of the following parts.(1)At first,the definition of slope safety factor,the main points of slope stability analysis by finit element mehthod and the basic thoughts of finite element method based on the strength reduction technique are introduced.Several failure evaluation criterions are discussed.The feasibility of finite element method based on the strength reduction technique is analysed with the homogeneous soil slope model of ACADS.(2)A failure evaluation criterion is developed from the energy rule of structure analysis.The models of two dimentional slope are analysed by finite element method with the failure evaluation criterion put forward in this thesis.The displacement of slope in the process of strength reduction and the position of sliding surface arediscussed.(3)The theory of transform in the results calculated based on different yield criterions is analysed.The correlation formulae are brought forward,and the feasibility is validate through model analysis.The infection of cohesive force,frictional angle,dilation angle,modulus of elasticity,Poisson ratio and the simplification of two dimentional slope model on the calculation of safety factor was discussed. The effect of various parameters are discussed using the orthogonal test method.(4)The stability analysis of the example of a cutting slope in the conditions before and after the excavation,and the reinforced condition has been done through the method of strength reduction finite element based on the failure evaluation criterion put forward in this thesis.The feasibility and effect of the method of this thesis used in the actual projects are discussed. In the end,the way of farther works is discussed briefly.