A new index combining weak layer and slab properties for snow instability prediction
Snow slope stability evaluation requires considering weak layer as well as slab properties – and in particular their interaction. We developed a stability index from snow micro-penetrometer (SMP) measurements and compared it to 129 concurrent point observations with the compression test (CT). The in...
Main Authors: | , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2015-01-01
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Series: | Natural Hazards and Earth System Sciences |
Online Access: | http://www.nat-hazards-earth-syst-sci.net/15/109/2015/nhess-15-109-2015.pdf |
Summary: | Snow slope stability evaluation requires considering weak
layer as well as slab properties – and in particular their interaction. We
developed a stability index from snow micro-penetrometer (SMP) measurements and
compared it to 129 concurrent point observations with the compression test
(CT). The index considers the SMP-derived micro-structural strength and the
additional load, which depends on the hardness of the surface layers. The new
quantitative measure of stability discriminated well between point
observations rated as either "poor" or "fair" (CT < 19) and those
rated as "good" (CT ≥ 19). However, discrimination power within the
intermediate range was low. We then applied the index to gridded snow
micro-penetrometer measurements from 11 snow slopes to explore the spatial
structure and possibly relate it to slope stability. Stability index
distributions on the 11 slopes reflected various possible strength and load
(stress) distributions that can naturally occur. Their relation to slope
stability was poor, possibly because the index does not consider crack
propagation. Hence, the relation between spatial patterns of point stability
and slope stability remains elusive. Whereas this is the first attempt of a
truly quantitative measure of stability, future developments should consider
a better reference of stability and incorporate a measure of crack
propagation. |
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ISSN: | 1561-8633 1684-9981 |