Numerical modelling of downward progressive failure in sensitive clays: the case of the 1976 landslide at Saint-Fabien, Québec

F. Tremblay-Auger, Ariane Locat, S. Leroueil, D. Demers

In the proceedings of: GeoSt. John's 2019: 72nd Canadian Geotechnical Conference

Session: Numerical Modeling of Landslides

ABSTRACT: The Saint-Fabien landslide occurred in December 1976, 270 km north-east of Quebec City, Canada. Passive and active failure zones were observed in the debris, indicating a downward progressive failure mechanism, unusual in Eastern Canadian clays. Conventional stability analysis was performed at the site and a factor of safety of 1.43 was obtained. This means that limit equilibrium analysis cannot explain the formation of the failure surface observed at Saint-Fabien. The initiation and the propagation of the failure were analysed through 1D numerical modelling using the concept of progressive failure. The methodology consists of two steps: first the calculation of the initial stresses in the slope with the finite element software PLAXIS 2D and second the modelling of progressive failure initiation and propagation with the finite element code BIFURC, developed at the Norwegian Geotechnical Institute.

RÉSUMÉ: Le glissement de Saint-au nord-est de la ville de Québec. Des zones passive et active ont été observées dans les débris, indiquant un mouvement translationnel progressif vers le bas, peu commun coefficient de sécurité de 1.43rmation de la surface de rupture observée à Saint-utilisant le concept de rupture progressive. Les deux étapes de cette analyse sont : premièrement le calcul des contraintes initiales dans la pente avec le logiciel par éléments finis PLAXIS 2D et deuxièmement la modélisation de la Géotechnique.

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Cite this article:
F. Tremblay-Auger; Ariane Locat; S. Leroueil; D. Demers (2019) Numerical modelling of downward progressive failure in sensitive clays: the case of the 1976 landslide at Saint-Fabien, Québec in GEO2019. Ottawa, Ontario: Canadian Geotechnical Society.

@article{Geo2019Paper181,author = F. Tremblay-Auger; Ariane Locat; S. Leroueil; D. Demers,title = Numerical modelling of downward progressive failure in sensitive clays: the case of the 1976 landslide at Saint-Fabien, Québec ,year = 2019}