Scaling properties of avalanches from a collapsing granular pile

Results of an experimental investigation of the scaling properties of a collapsing rice pile induced by reducing the length of the base support of the pile are reported. It is found that two angles of repose are needed to describe the shape of the collapsing granular pile. Corresponding to these two angles of repose, the collapse of the granular pile can be characterized by local and global avalanches. Furthermore, it is found that the probability distributions of the avalanches depend on the sizes of the avalanches under consideration. Effects of the shape of the granular particles on the avalanches are also discussed.