Item: Discrete Element Modeling of Crack Propagation in Weak Snowpack Layers
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Title: Discrete Element Modeling of Crack Propagation in Weak Snowpack Layers
Proceedings: International Snow Science Workshop 2014 Proceedings, Banff, Canada
Authors:
- Johan Gaume [ WSL Institute for Snow and Avalanche Research SLF, Davos Dorf, Switzerland ]
- Alec van Herwijnen [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Jürg Schweizer [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Guillaume Chambon [ IRSTEA, Grenoble, France ]
- Karl W. Birkeland [ USDA Forest Service National Avalanche Center, Bozeman, MT, USA ]
Date: 2014-09-29
Abstract: Dry-snow slab avalanches are generally caused by a sequence of fracture processes including (1) failure initiation in a weak snow layer underlying a cohesive slab, (2) crack propagation within the weak layer and (3) tensile fracture through the slab which leads to its detachment. During the past decades, theoretical and experimental work has gradually led to a better understanding of the fracture process in snow involving the collapse of the structure in the weak layer during fracture. This now allows us to better model failure initiation and the onset of crack propagation, i.e. to estimate the critical length required for crack propagation. On the other hand, our understanding of dynamic crack propagation is still very limited. For instance, it is not uncommon to perform field measurements with widespread crack propagation on one day, while a few days later, with very little changes to the snowpack, crack propagation does not occur anymore. Thus far, there is no clear theoretical framework to interpret such observations, and it is not clear how and which snowpack properties affect dynamic crack propagation. To shed more light on this issue, we performed numerical propagation saw test (PST) experiments applying the discrete element (DE) method and compared the numerical results with field measurements based on particle tracking. The goal is to investigate the influence of weak layer failure and the mechanical properties of the slab on crack propagation. Crack propagation velocities and distances before fracture arrest derived from the DE simulations were in good agreement with experimental data suggesting that the simulations can reproduce crack propagation in PSTs.
Language of Article: English
Presenters:
Keywords: Snow avalanche, crack propagation, PST, discrete element modeling, slab, weak layer
Page Number(s): 150-157
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Digital Abstract Not Available
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