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| Titel |
Effects of flow regime and sensor geometry on snow avalanche impact pressure |
| VerfasserIn |
Djebar Baroudi, Betty Sovilla, Emmanuel Thibert |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250047976
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| Zusammenfassung |
| Impact pressures of snow avalanches have been measured at the Vallée de la Sionne experimental test site using two kinds of sensors with different sizes placed at different locations in the avalanche flow. Pressures measured for a fast dry snow avalanche and a slow wet snow avalanche are compared and discussed. The pressures recorded in the dense flow of a dry snow avalanche agree well for the two types of sensors used, showing negligible dependence on the measurement device. On the other hand, significantly different pressures are measured in the slow dense flow of a wet snow avalanche. This is attributed to the slow drag and bulk flow of this type of avalanche, leading to the formation and collapsing of force-chain structures against the different surfaces of the sensors. At a macroscopic scale, limit state analysis can be used to explain such a mechanism by a shear failure occurring between freely flowing snow and a confined snow volume against the sensor according to a Mohr-Coulomb failure criterion. The proposed model explains how impact pressure can be up to 8 times higher than the hydrostatic snow pressure in wet cohesive slow avalanches and its dependence on sensor geometry. |
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