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Titel |
Evaluating snow weak-layer failure parameters through inverse finite element modelling of shaking-platform experiments |
VerfasserIn |
E. A. Podolskiy, G. Chambon, M. Naaim, J. Gaume |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1561-8633
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Digitales Dokument |
URL |
Erschienen |
In: Natural Hazards and Earth System Sciences ; 15, no. 1 ; Nr. 15, no. 1 (2015-01-15), S.119-134 |
Datensatznummer |
250119276
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Publikation (Nr.) |
copernicus.org/nhess-15-119-2015.pdf |
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Zusammenfassung |
Snowpack weak layers may fail due to excess stresses of various natures,
caused by snowfall, skiers, explosions or strong ground motion due to
earthquakes, and lead to snow avalanches. This research presents a numerical
model describing the failure of "sandwich" snow samples subjected to
shaking. The finite element model treats weak layers as interfaces with
variable mechanical parameters. This approach is validated by reproducing
cyclic loading snow fracture experiments. The model evaluation revealed that
the Mohr–Coulomb failure criterion, governed by cohesion and friction angle,
was adequate to describe the experiments. The model showed the complex,
non-homogeneous stress evolution within the snow samples and especially the
importance of tension on fracture initiation at the edges of the weak layer,
caused by dynamic stresses due to shaking. Accordingly, a simplified analytical
solution, ignoring the inhomogeneity of tangential and normal stresses along
the failure plane, may incorrectly estimate the shear strength of the weak
layers. The values for "best fit" cohesion and friction angle were ≈1.6 kPa
and 22.5–60°. These may constitute valuable first approximations
in mechanical models used for avalanche forecasting. |
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