Enhanced finite element analysis of progressive failure of slopes based on cohesive zone model

The description of discontinuous deformation and the simulation of shear band propagation are the key to the progressive failure analysis of slopes. A novel numerical method is presented based on the cohesive zone model and the enhanced finite element method. Firstly, the deformation of the shear band is resolved into the relative displacements determined by regular strain and additional strain respectively, a description which equally replaces the weak discontinuous deformation with strong form is adopted, and the shear band stress-additional relative displacement softening constitutive relation is represented by means of the cohesive law. Secondly, the relative displacement is described by the enhanced finite element method, and corresponding shear band element without thickness is constructed. Finally, a finite element algorithm for modeling the propagation of shear bands is proposed. Through numerical examples, it is demonstrated that the proposed method is not only able to consider the softening character of shear band, but also overcomes the mesh sensitivity in modeling the standard shear band.