Upper-bound solution of safety factor for slope with broken-line slip surface based on plasticity limit analysis

Based on the theory of limit analysis,through studying on the limit analysis method to calculate slope safety factor,the model of limit analysis for slope with broken-line slip surface is proposed.Furthermore,the upper-bound solution of slope safety factor is obtained according to the theory of virtual power theory.The new method considers not only the effect of the inner energy dissipation produced in the broken-line slip surface and the vertical velocity discontinuous face,but also the effect of the outer power produced by self-weight and external load.It's suitable for accumulated body slope with broken-line slip surface.As a case study,the author used the new method to analyze the stability of the Sanmashan landslide in the area of the Three Gorges Reservoir.Compared with the computing result of imbalance thrust force method,the method was proved.