ABSTRACT
The shearing characteristics of granular materials are depend on their diameter, fabric and boundary conditions. Numerical simulations of triaxial test have been performed to evaluate the influence of these conditions using two-dimensional and three-dimensional distinct element method. The uniform and distributed radius models were computed with flexible and rigid stress-controlled boundaries. The stress controlled boundary of three-dimensional analyses is constructed using triangular mesh by Delaunay triangulation. Clear shear bands were observed except the distributed radius model with rigid boundary and three-dimensional distributed radius models. The uniform radius models have a big drop in axial stress after they indicate the high peak axial stress. The distributed radius models have low peak axial stress. Although shear bands could not be observed in three-dimensional distributed radius models clearly, they could be observed using particle motions. The strain in the shear bands was larger than the strain elsewhere.
