Author(s): Aronne Armanini; Anna Paris
Linked Author(s): Aronne Armanini
Keywords: No Keywords
Abstract: One of the difficulties in modeling debris flow is the need for resistance formulae suited to describe the behavior of various flow regimes, ranging from the steep upper reaches of the channel to the mild flow in the deposition basins. For this purpose, a set of experiments involving flow mixtures of non-cohesive particles and water has been carried out in a laboratory flume under steady uniform flow conditions with different solid and liquid discharges. In highly-concentrated flows, the shear stress is due to the combined effect of the deformation of the liquid phase (grain roughness turbulence) and of inter-particle collisions. Therefore, a sum of effects approach of the two causes has been proposed, combining the DarcyWeisbach equation and the Bagnoldian grain-inertia theory. Comparison between predicted and measured data is relatively good, provided that the maximum concentration used (solid concentration in static conditions after the deposit) is lower than the maximum possible concentration (maximum packing concentration). The theoretical prediction reproduced correctly the general trend of the data, while the experimental measurements seemed to have been less sensitive to the relative roughness, h/d.
Year: 2009