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Main Authors: Meloche, Francis, Bobillier, Grégoire, Guillet, Louis, Gauthier, Francis, Langlois, Alexandre, Gaume, Johan
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2406.01360
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author Meloche, Francis
Bobillier, Grégoire
Guillet, Louis
Gauthier, Francis
Langlois, Alexandre
Gaume, Johan
author_facet Meloche, Francis
Bobillier, Grégoire
Guillet, Louis
Gauthier, Francis
Langlois, Alexandre
Gaume, Johan
contents Dry-snow slab avalanches are considered to be the most difficult to predict, yet the deadliest avalanche types. The release of snow slab avalanches starts with a initial failure in a weak layer that may propagate across the slope until the slab fractures and slides. The evaluation of crack propagation area is a primary concern for avalanche forecasters. The purpose of this study is to test the hypothesis that the heterogeneity of snowpack properties is one of the primary factors that may potentially stop dynamic crack propagation. To test this assumption, we use a depth-averaged Material Point Method (DA-MPM) for efficient elasto-plastic modeling of snow slab avalanches. Our analysis includes scenarios involving i) pure-elastic slabs and ii) elasto-plastic slabs. In the first scenario, we report a significant decrease in slab tensile stress with increasing crack speed compared to quasi-static theory. In addition, we quantify the effect of weak layer heterogeneity and softening fracture energy on the crack stopping mechanism. In the second scenario, we analyse the interplay between weak layer heterogeneity and slab tensile fracture and quantify their combined effect on crack arrest. Results are interpreted through a scaling law relating the crack arrest distance to two dimensionless numbers related to weak layer strength variability and slab tensile fracture. Furthermore, the proposed model is applied to field campaigns in which spatial variations of weak layer shear strength were measured. Finally, DA-MPM simulations are performed on three-dimensional terrain with spatial variations revealing interesting release patterns. This research and the proposed methods can not only enhance our comprehension of the factors influencing avalanche release sizes,and possibly, the design of new mitigation measures for avalanche start zones.
format Preprint
id arxiv_https___arxiv_org_abs_2406_01360
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Modeling crack arrest in snow slab avalanches -- towards estimating avalanche release sizes
Meloche, Francis
Bobillier, Grégoire
Guillet, Louis
Gauthier, Francis
Langlois, Alexandre
Gaume, Johan
Geophysics
Dry-snow slab avalanches are considered to be the most difficult to predict, yet the deadliest avalanche types. The release of snow slab avalanches starts with a initial failure in a weak layer that may propagate across the slope until the slab fractures and slides. The evaluation of crack propagation area is a primary concern for avalanche forecasters. The purpose of this study is to test the hypothesis that the heterogeneity of snowpack properties is one of the primary factors that may potentially stop dynamic crack propagation. To test this assumption, we use a depth-averaged Material Point Method (DA-MPM) for efficient elasto-plastic modeling of snow slab avalanches. Our analysis includes scenarios involving i) pure-elastic slabs and ii) elasto-plastic slabs. In the first scenario, we report a significant decrease in slab tensile stress with increasing crack speed compared to quasi-static theory. In addition, we quantify the effect of weak layer heterogeneity and softening fracture energy on the crack stopping mechanism. In the second scenario, we analyse the interplay between weak layer heterogeneity and slab tensile fracture and quantify their combined effect on crack arrest. Results are interpreted through a scaling law relating the crack arrest distance to two dimensionless numbers related to weak layer strength variability and slab tensile fracture. Furthermore, the proposed model is applied to field campaigns in which spatial variations of weak layer shear strength were measured. Finally, DA-MPM simulations are performed on three-dimensional terrain with spatial variations revealing interesting release patterns. This research and the proposed methods can not only enhance our comprehension of the factors influencing avalanche release sizes,and possibly, the design of new mitigation measures for avalanche start zones.
title Modeling crack arrest in snow slab avalanches -- towards estimating avalanche release sizes
topic Geophysics
url https://arxiv.org/abs/2406.01360