Mechanics of dry granular flows driven by gravity

Dry granular flows are an important paradigm for a large number of problems, from industrial applications to geophysical events. Most of the research published has studied inclined granular flows over bumpy and at rigid base, while only few of them have been focused on fully developed steady flows over an erodible beds. This kind of flows are important to understand the dynamics of complex phenomena such as dense snow-avalanches and landslides, whose rheology is still ambiguous and not well defined. In this thesis, we focus on the following three aspects: (1) dynamics of uniform flows over loose bed, where the condition of uniformity and steadiness has accurately checked, (2) the influence of collisional parameters on the behavior of the flow, (3) the side-wall effect. Experimental investigations were carried out in laboratory through imaging techniques and direct methods to analyze the stresses exerted by the flow. The thesis contributes with accurate measurements of the mean velocity, solid concentration, and granular temperature pro files obtained along the depth and the free surface of the flow. Considerations have been derived in comparison to the existing data, pointing out the importance of collisional parameters and the conditions for uniform and steady flows. Experimental evaluation of the stresses was carried out at the side-walls of the channelized granular flows by the means of new device developed in the laboratory and tested for different con figurations of the flow.