Computing Granular Avalanches Over Complex Topography
Abstract
Rapid Granular mass movement phenomena such as snow avalanches, rock avalanches and debris flows are natural phenomena that occur in mountainous areas throughout the world. Whereas the physical understanding of their release is quite complex, depend of many very different parameters and hence difficult to understand, the understanding of motion and stopping is less difficult and is investigated in this work using numerical simulations. Savage and Hutter (1989) proposed a one-dimensional continuum model for the numerical simulation of dry granular mixtures. It assumes an incompressible shallow flow behaviour and that the flowing mass behaves as a Mohr-Coulomb plastic material when yielding. This was extended by Gray et al. (1998) and Iverson & Denlinger on multi dimensions and by Iverson & Denlinger (2001) and Savage & Iverson (2003) for rapid two-phase flow phenomena. In this paper we are presenting a new numerical model approach for the solution of the Iverson & Denlinger equations in the case of dry rapid granular flows, with the following characteristics: - it solves the conservation laws for rapid dry granular flows. - it operates on unstructured triangular grids in the finite volume context. - it works with a dynamic adaptive grid strategy. - it operates with a higher order approximate Riemann solver and a new source term balancing technique. - it operates in a parallelized environment. We tested the numerical model against several numerical testproblems and laboratory experiments such as: - the classical lake at rest problem; - a dry granular flow down an inclined chute; - a dry granular flow down an inclined plane with and without a flow diverting obstacle; - a dry granular flow down an unregular laboratory topography .
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2004
- Bibcode:
- 2004AGUFM.H33G..01V
- Keywords:
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- 3210 Modeling;
- 1815 Erosion and sedimentation;
- 1824 Geomorphology (1625)