Item: On the Failure Criterion of Weak Snowpack Layers Using the Discrete Element Method
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Title: On the Failure Criterion of Weak Snowpack Layers Using the Discrete Element Method
Proceedings: International Snow Science Workshop 2014 Proceedings, Banff, Canada
Authors:
- Johan Gaume [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Guillaume Chambon [ IRSTEA, Grenoble, France ]
- Ingrid Reiweger [ WSL Institute for Snow and Avalanche Research SLF, Davos, 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 ]
Date: 2014-09-29
Abstract: The release of dry-snow slab avalanches start with a local failure in a weak snow layer underlying a cohesive slab followed by crack propagation within the weak layer. Our knowledge of these processes is limited by the complex microstructure of snow. It is not clear how to characterize the mechanical behavior of weak snowpack layers under mixed-mode loading. While most current studies assume pure shear or Mohr-Coulomb failure criterions, which may apply for non-persistent weak layers or weak interfaces, such a failure criterion does not account for the collapsible nature of some weak snowpack layers. To clarify this issue, we use the discrete element (DE) method to investigate the failure criterion of different types of weak layers. As the DE model mimics the high porosity of snow, the collapse of the structure in the weak layer during fracture can be studied. Simple shear loading simulations were carried out for different slope angles which enabled to highlight a new mixed-mode shear-compression failure envelope. Simulations of propagation saw tests (PST) were performed to analyze the influence of weak layer collapse and the mechanical properties of the slab on the critical length required for the onset of crack propagation. Finally, a simple analytical model able to accurately reproduce the DE simulations is proposed.
Language of Article: English
Presenters:
Keywords: Snow avalanche, failure criterion, Mohr-Coulomb, crack propagation, discrete element modeling, snow slab, weak layer.
Page Number(s): 724-731
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Digital Abstract Not Available
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