Actions of snow avalanches on a protection gallery

Better knowledge of the actions of snow avalanches on slightly inclined protection galleries such as snow sheds is vital for improving the design of such structures. Experimental measurements on a plate equipped with force sensors were carried out on a full-scale avalanche test site at Col du Lautaret (French Alps). For each artificial release of an avalanche, the impact effect and the resulting temporal variations were measured. This real-scale experiment was completed by laboratory-scale experimental tests using granular flows in an inclined channel that identified the relation between load and slope change. These experiments allowed us to measure the granular temperature of the flow. Finally, to assess the dynamic effect of the avalanche loading on the structure, numerical simulations of a real gallery were conducted with a simplified multifiber model, taking into account the tempo-spatial evolutions of the impact pressure observed during experiments.

► We experimented the actions of real-scale avalanches on a quasi-horizontal structure.
► The “basal friction coefficient” varied between 0.2 and 0.6.
► We conducted laboratory-scale experiments using granular flows in an inclined channel.
► Pressure reaches 10 times the equivalent solicitation when gallery is near the slope.
► The theoretical shape of the granular temperature was found experimentally.