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Modeling of Crack Propagation in Weak Snowpack Layers Using the Discrete Element Method : Volume 9, Issue 1 (28/01/2015)

By Gaume, J.

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Book Id: WPLBN0004023263
Format Type: PDF Article :
File Size: Pages 45
Reproduction Date: 2015

Title: Modeling of Crack Propagation in Weak Snowpack Layers Using the Discrete Element Method : Volume 9, Issue 1 (28/01/2015)  
Author: Gaume, J.
Volume: Vol. 9, Issue 1
Language: English
Subject: Science, Cryosphere, Discussions
Collections: Periodicals: Journal and Magazine Collection, Copernicus GmbH
Historic
Publication Date:
2015
Publisher: Copernicus Gmbh, Göttingen, Germany

Citation

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Herwijnen, A. V., Schweizer, J., Chambon, G., Birkeland, K. W., & Gaume, J. (2015). Modeling of Crack Propagation in Weak Snowpack Layers Using the Discrete Element Method : Volume 9, Issue 1 (28/01/2015). Retrieved from http://www.ebooklibrary.org/


Description
Description: WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland. 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 and fracture arrest propensity 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 and fracture arrest propensity. Crack propagation speeds and distances before fracture arrest were derived from the DE simulations for different snowpack configurations and mechanical properties. Then, the relation between mechanical parameters of the snowpack was taken into account so as to compare numerical and experimental results, which were in good agreement, suggesting that the simulations can reproduce crack propagation in PSTs. Finally, an in-depth analysis of the mechanical processes at play was carried out which led to suggestions for minimum column length in field PSTs.

Summary
Modeling of crack propagation in weak snowpack layers using the discrete element method

Excerpt
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