Discrete element analysis of the deformation and failure characteristics of deposits during biaxial compression based on flexible boundary

Abstract

Deposits is a kind of discontinuous and non-uniform material composed of soils and stones. Due to the effect of the internal meso-structure, its deformation and failure mechanism under external load is more complicated than the general soil. In this paper, the deformation and failure process of deposits and its shear band formation under biaxial compression were investigated by discrete element simulations based on flexible boundary, and the influence of confining pressure and the content and spatial distribution of its internal stones on the deformation and failure characteristics were analyzed. The simulation results show that the deformation and failure of deposit is a progressive failure process. The formation of its shear band starts to appear and gradually develop before peak stress during compression, and it penetrates at peak stress and gradually expands after peak stress. The deformation and failure process of deposits is not only affected by its internal stone content and spatial distribution, but also depends on the confining pressure. In general, the morphology of the shear band after failure shows an asymmetrically X-shaped arrangement because of the effect of stones.