Avalanche mobility induced by the presence of an erodible bed and associated entrainment
نویسندگان
چکیده
[1] The partial fluidization model developed by Aranson and Tsimring (2002) is used to simulate the spreading of a 2D circular cap of granular material over an erodible bed made of the same material. Numerical results show that the presence of even a very thin layer of granular material lying on the solid bed strongly increases the mobility of granular flows. Furthermore, as the thickness of the granular layer increases, the dynamics of the flowing mass changes from a decelerating avalanche to a traveling wave. Numerical simulation suggest that surges are generated if enough mass is entrained, increasing the energy of the flowing material and balancing the energy lost by friction. Citation: Mangeney, A., L. S. Tsimring, D. Volfson, I. S. Aranson, and F. Bouchut (2007), Avalanche mobility induced by the presence of an erodible bed and associated entrainment, Geophys. Res. Lett., 34, L22401, doi:10.1029/2007GL031348.
منابع مشابه
Erosion and mobility in granular collapse over sloping beds
[1] We describe laboratory experiments of granular material flowing over an inclined plane covered by an erodible bed, designed to mimic erosion processes of natural flows travelling over deposits built up by earlier events. Two controlling parameters are the inclination of the plane and the thickness of the erodible layer. We show that erosion processes can increase the flowmobility (i.e., run...
متن کاملAn analysis of the entrainment effect of dry debris avalanches on loose bed materials
Substrate entrainment can greatly influence the mass movement process of a debris avalanche because it can enlarge the landslide volume and change the motion characteristics of the sliding masses. To study the interaction between debris avalanches and erodible substrate, physical modeling experiments varying in the mass of granular flow and substrate thickness were performed. The experimental r...
متن کاملExperimental Analysis on the Water Entrainment of Turbidity Current over a Mobile Bed
Study of Turbidity Current, as one of the most important phenomena affecting the sedimentation in the reservoirs of dams, is essential. Since most of the research studies have been conducted under experimental conditions on rigid beds, the effect of erodible bed and the formation of the bed form on the turbidity current specifications is not yet clear. Therefore, in this Research, the study of ...
متن کاملFundamental changes of granular flow dynamics, deposition, and erosion processes at high slope angles: Insights from laboratory experiments
Entrainment of underlying debris by geophysical flows can significantly increase the flow deposit extent. To study this phenomenon, analog laboratory experiments have been conducted on granular column collapse over an inclined channel with and without an erodible bed made of similar granular material. Results show that for slope angles below a critical value θc, between 10◦ and 16◦, the run out...
متن کاملA mechanical erosion model for two-phase mass flows
Erosion, entrainment and deposition are complex and dominant, but yet poorly understood, mechanical processes in geophysical mass flows. Here, we propose a novel, process-based, two-phase, erosiondeposition model capable of adequately describing these complex phenomena commonly observed in landslides, avalanches, debris flows and bedload transport. The model is based on the jump in the momentum...
متن کامل