Varying dam height to shorten the run-out of dense avalanche flows: developing a scaling law from laboratory experiments

Dry and dense snow avalanches are considered as dry granular flows. Their interaction with dams is the main objective of this paper. We studied how varying the dam height could shorten a granular avalanche run-out thanks to a set of simple laboratory experiments carried out on different scales. Shortening the run-out was expected to depend on two effects: (i) storage of the granular material upstream of the dam and (ii) local energy dissipations. A scaling law is highlighted. As suggested by dimensional arguments, the contribution of the local energy dissipations was shown to be more dominant than the storage effects.