Analytical solution of dam break wave in dry granular flows

The paper analyzes the dynamic of a wave arising from a rapid dam break of dry granular material. The research is motivated by the importance that granular media have in many different areas and in specific environmental engineering problems. In order to reproduce the front position a one-dimensional model, considering both Coulomb and collisional stresses, is presented. The proposed model includes also the effect of the material’s bed and internal friction angles, through a pressure coefficient. A simple analytical solution based on characteristic theory is deduced and the obtained results are compared with the experimental evidences. The experiments have been performed reproducing a sudden collapse of dry grains of sand in an apparatus consisting of a reservoir and a horizontal rectangular channel, separated by a vertical fast opening sluice gate. Different initial column heights in the reservoir have been considered. The performance of the proposed model is discussed, along with its limitations and possible improvements.