Flow of dense avalanches past obstructions

Abstract One means of preventing areas from being hit by avalanches is to divert the flow by straight or curved walls or tetrahedral or cylindrical-type structures. Thus, there arises the question how a given avalanche flow is changed regarding the diverted-flow depth and flow direction. In this paper a report is given on laboratory experiments performed for gravity-driven dense granular flows down an inclined plane obstructed by plane wall and tetrahedral wedge. It was observed that these flows are accompanied by shocks induced by the presence of the obstacles. These give rise to a transition from super-to subcritical flow of the granular avalanche, associated with depth and velocity changes. It is demonstrated that with an appropriate shock-capturing integration technique for the Savage-Hutter theory, the shock formation for a finite-mass granular flow sliding from an inclined plane into a horizontal run-out zone is well described, as is the shock formation of the granular flow on either side of a tetrahedral protection structure.

[1]  K. Hutter,et al.  Unconfined flow of granular avalanches along a partly curved surface. I. Theory , 1994, Proceedings of the Royal Society of London. Series A: Mathematical and Physical Sciences.

[2]  K. Hutter,et al.  Motion of a granular avalanche in an exponentially curved chute: experiments and theoretical predictions , 1991, Philosophical Transactions of the Royal Society of London. Series A: Physical and Engineering Sciences.

[3]  G. Tadmor,et al.  Non-oscillatory Central Schemes for Multidimensional Hyperbolic Conservation Laws , 1997 .

[4]  Kolumban Hutter,et al.  Channelized free-surface flow of cohesionless granular avalanches in a chute with shallow lateral curvature , 1999, Journal of Fluid Mechanics.

[5]  Kolumban Hutter,et al.  Gravity-driven free surface flow of granular avalanches over complex basal topography , 1999, Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[6]  Kolumban Hutter,et al.  Motion of a granular avalanche in a convex and concave curved chute: experiments and theoretical predictions , 1993, Philosophical Transactions of the Royal Society of London. Series A: Physical and Engineering Sciences.

[7]  J. Gray,et al.  Limiting stress states in granular avalanches , 1998, Annals of Glaciology.