 |
| Titel |
Modeling of crack propagation in weak snowpack layers using the discrete element method |
| VerfasserIn |
J. Gaume, A. Herwijnen, G. Chambon, K. W. Birkeland, J. Schweizer |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1994-0416
|
| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 9, no. 5 ; Nr. 9, no. 5 (2015-10-08), S.1915-1932 |
| Datensatznummer |
250116856
|
| Publikation (Nr.) |
 copernicus.org/tc-9-1915-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
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.
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, in order to compare the numerical and experimental results,
the slab mechanical properties (Young's modulus and strength) which are not
measured in the field were derived from density. The simulations nicely
reproduced the process of crack propagation observed in field PSTs. Finally,
the mechanical processes at play were analyzed in depth which led to
suggestions for minimum column length in field PSTs. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|