Influence of weak-layer heterogeneity on snow slab avalanche release: application to the evaluation of avalanche release depths
International audience The evaluation of avalanche release depths constitutes a great challenge for risk assessment in mountainous areas. This study focuses on slab avalanches, which generally result from the rupture of a weak layer underlying a cohesive slab. We use the finite-element code Cast3M t...
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ftunivnantes:oai:HAL:hal-02599058v1 2023-05-15T16:57:26+02:00 Influence of weak-layer heterogeneity on snow slab avalanche release: application to the evaluation of avalanche release depths Influence de l'hétérogénéité des propriétés mécanique des couches fragiles sur le déclenchement des avalanches de plaque : application à la prédétermination des épaisseurs de départ d'avalanches Gaume, J. Chambon, Guillaume Eckert, Nicolas Naaim, Mohamed Erosion torrentielle neige et avalanches (UR ETGR (ETNA)) Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) 2013 https://hal.inrae.fr/hal-02599058 https://doi.org/10.3189/2013JoG12J161 en eng HAL CCSD International Glaciological Society info:eu-repo/semantics/altIdentifier/doi/10.3189/2013JoG12J161 hal-02599058 https://hal.inrae.fr/hal-02599058 doi:10.3189/2013JoG12J161 IRSTEA: PUB00039485 WOS: 000323189600003 ISSN: 0022-1430 EISSN: 1727-5652 Journal of Glaciology https://hal.inrae.fr/hal-02599058 Journal of Glaciology, International Glaciological Society, 2013, 59 (215), pp.423-437. ⟨10.3189/2013JoG12J161⟩ [SDE]Environmental Sciences info:eu-repo/semantics/article Journal articles 2013 ftunivnantes https://doi.org/10.3189/2013JoG12J161 2022-11-02T01:07:37Z International audience The evaluation of avalanche release depths constitutes a great challenge for risk assessment in mountainous areas. This study focuses on slab avalanches, which generally result from the rupture of a weak layer underlying a cohesive slab. We use the finite-element code Cast3M to build a mechanical model of the slab/weak-layer system, taking into account two key ingredients for the description of avalanche release: weak-layer heterogeneity and stress redistribution via slab elasticity. The system is loaded by increasing the slope angle until rupture. We first examine the cases of one single and two interacting weak spots in the weak layer, in order to validate the model. We then study the case of heterogeneous weak layers represented through Gaussian distributions of the cohesion with a spherical spatial covariance. Several simulations for different realizations of weak-layer heterogeneity are carried out and the influence of slab depth and heterogeneity correlation length on avalanche release angle distributions is analyzed. We show, in particular, a heterogeneity smoothing effect caused by slab elasticity. Finally, this mechanically based probabilistic model is coupled with extreme snowfall distributions. A sensitivity analysis of the predicted distributions enables us to determine the values of mechanical parameters that provide the best fit to field data. Article in Journal/Newspaper Journal of Glaciology Université de Nantes: HAL-UNIV-NANTES Journal of Glaciology 59 215 423 437 |
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Open Polar |
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Université de Nantes: HAL-UNIV-NANTES |
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ftunivnantes |
language |
English |
topic |
[SDE]Environmental Sciences |
spellingShingle |
[SDE]Environmental Sciences Gaume, J. Chambon, Guillaume Eckert, Nicolas Naaim, Mohamed Influence of weak-layer heterogeneity on snow slab avalanche release: application to the evaluation of avalanche release depths |
topic_facet |
[SDE]Environmental Sciences |
description |
International audience The evaluation of avalanche release depths constitutes a great challenge for risk assessment in mountainous areas. This study focuses on slab avalanches, which generally result from the rupture of a weak layer underlying a cohesive slab. We use the finite-element code Cast3M to build a mechanical model of the slab/weak-layer system, taking into account two key ingredients for the description of avalanche release: weak-layer heterogeneity and stress redistribution via slab elasticity. The system is loaded by increasing the slope angle until rupture. We first examine the cases of one single and two interacting weak spots in the weak layer, in order to validate the model. We then study the case of heterogeneous weak layers represented through Gaussian distributions of the cohesion with a spherical spatial covariance. Several simulations for different realizations of weak-layer heterogeneity are carried out and the influence of slab depth and heterogeneity correlation length on avalanche release angle distributions is analyzed. We show, in particular, a heterogeneity smoothing effect caused by slab elasticity. Finally, this mechanically based probabilistic model is coupled with extreme snowfall distributions. A sensitivity analysis of the predicted distributions enables us to determine the values of mechanical parameters that provide the best fit to field data. |
author2 |
Erosion torrentielle neige et avalanches (UR ETGR (ETNA)) Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) |
format |
Article in Journal/Newspaper |
author |
Gaume, J. Chambon, Guillaume Eckert, Nicolas Naaim, Mohamed |
author_facet |
Gaume, J. Chambon, Guillaume Eckert, Nicolas Naaim, Mohamed |
author_sort |
Gaume, J. |
title |
Influence of weak-layer heterogeneity on snow slab avalanche release: application to the evaluation of avalanche release depths |
title_short |
Influence of weak-layer heterogeneity on snow slab avalanche release: application to the evaluation of avalanche release depths |
title_full |
Influence of weak-layer heterogeneity on snow slab avalanche release: application to the evaluation of avalanche release depths |
title_fullStr |
Influence of weak-layer heterogeneity on snow slab avalanche release: application to the evaluation of avalanche release depths |
title_full_unstemmed |
Influence of weak-layer heterogeneity on snow slab avalanche release: application to the evaluation of avalanche release depths |
title_sort |
influence of weak-layer heterogeneity on snow slab avalanche release: application to the evaluation of avalanche release depths |
publisher |
HAL CCSD |
publishDate |
2013 |
url |
https://hal.inrae.fr/hal-02599058 https://doi.org/10.3189/2013JoG12J161 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
ISSN: 0022-1430 EISSN: 1727-5652 Journal of Glaciology https://hal.inrae.fr/hal-02599058 Journal of Glaciology, International Glaciological Society, 2013, 59 (215), pp.423-437. ⟨10.3189/2013JoG12J161⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.3189/2013JoG12J161 hal-02599058 https://hal.inrae.fr/hal-02599058 doi:10.3189/2013JoG12J161 IRSTEA: PUB00039485 WOS: 000323189600003 |
op_doi |
https://doi.org/10.3189/2013JoG12J161 |
container_title |
Journal of Glaciology |
container_volume |
59 |
container_issue |
215 |
container_start_page |
423 |
op_container_end_page |
437 |
_version_ |
1766048985426952192 |