| Titre | Preliminary analysis of the failure mechanism at the Nomash River Landslide, Vancouver Island, British Columbia, Canada |
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| Auteur | Sivak, T J; Brideau, M A; Stead, D; Couture, R; Guthrie, R |
| Source | Geologically Active: Proceedings of the 11th IAEG Congress; par Williams, A L (éd.); Pinches, G M (éd.); Chin, C Y (éd.); McMorran, T J (éd.); Massey, C I (éd.); 2010 p. 691-699 |
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| Année | 2010 |
| Séries alt. | Secteur des sciences de la Terre, Contribution externe 20100023 |
| Réunion | 11th IAEG Congress; Aucklaud; NZ; Septembre 5-10, 2010 |
| Document | livre |
| Lang. | anglais |
| Media | papier |
| Province | Colombie-Britannique |
| SNRC | 92E/15 |
| Région | Nomash River; Île de Vancouver; Tahsis |
| Lat/Long OENS | -127.0000 -126.5000 50.0000 49.7500 |
| Sujets | glissements de terrain; dépôts de glissement de terrain; dépôts de pentes; glissements de pentes; stabilité des pentes; analyses de la stabilité des pentes; géologie de l'ingénieur; géologie des dépôts
meubles/géomorphologie |
| Illustrations | cartes de localisation; diagrammes stéréographiques tournant de wulff; photographies; diagrammes |
| Programme | Géoscience pour la sécurité publique Lignes directrices nationales sur l'évaluation et la réduction des risques naturels |
| Diffusé | 2010 01 01 |
| Résumé | (disponible en anglais seulement)
The Nomash River is situated within a steep-sided valley approximately 6 km northwest of Tahsis, on the northwest coast of Vancouver Island. A 0.3 Mm3 landslide
originating on the summit of a 430-m high rock wall failed on April 25th or 26th 1999, destroying a logging road and temporarily blocking the Nomash River. The landslide escarpment contains two crystalline limestone faces of the Quatsino Formation
which are crosscut by mafic dykes and sills. The landslide is thought to have been triggered by freeze and thaw cycles over the preceding days. The objective of this study was to identify feasible failure mechanisms based on field data measurements
of discontinuity orientations and characteristics. This was accomplished by conducting kinematic, limit equilibrium surface wedge, and block theory analyses. Based on these techniques a wedge failure is the preferred failure mechanism. Geological
Strength Index (GSI) estimates and Unconfined Compressive Strength (UCS) values derived from point load testing were used to characterize the rock mass. |
| GEOSCAN ID | 263350 |
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