A granular heap is formed when grains are continuously poured on a surface. The characteristics of such a heap can vary significantly depending on the pouring protocol. In the present work, we show that the velocity at the base of a granular heap, during a steady flowing state, varies significantly when the pouring protocols differ. We performed discrete element simulations of a granular heap formed on a thin rectangular base for two pouring protocols – i) grains poured through a narrow stream and ii) grains poured through a wide stream spanning the entire base. The kinematic properties of grains at the heap base highlighted some interesting characteristics, notably the transition from slow flow to rapid flow and the absence of a static region in the centre of the heap. These results are significant from the viewpoint of stress distribution in bulk granular systems since the orientation of granular contacts and the distribution of forces within the bulk are influenced by the velocity field during flow.
Khan et al. (Mon,) studied this question.