Abstract:Considering the Laplace operator of plastic strains in the double yield functions,the control equations of the generalized gradient-dependent plasticity model are established to describe both the strain localization characteristics and the basic mechanical characteristics of geomaterials. In order to get the numerical solution of the control equations,the displacement and the plastic multiplier are discretized by virtual work equation and the consistency condition of yield functions separately. A set of nonlinear equations taking the displacements and the plastic factors of nodes as the unknown variables are obtained;and the boundary conditions and the increment algorithm of the equations are given. The numerical examples indicate that:(1) when strain localization appears,the plastic shear strain and the plastic bulk strain mainly concentrate in localization band;(2) the mesh-dependency does not appear any more when the size of mesh changes;(3) when the parameters reflecting localization increase,the width of the strain localization band will be widened obviously.