Contribution à l'étude des étalements dans les argiles sensibles de la mer de Champlain- Étude des étalements de Casselman (1971) et de Saint-Luc-de-Vincennes (1986)
|Advisor:||Locat, Ariane; Leroueil, Serge|
|Abstract:||This M.Sc. thesis presents, in the first part, the geotechnical and geomorphological analysis of the 1971 landslide in Casselman, Ontario. The geomorphological characteristics identified inside the landslide scar confirmed it was a spread. The soil involved is a sensitive clay from the Champlain Sea, normally to slightly overconsolidated (OCR from 1.0 to 1.2) with liquidity index ranging from 1.0 to 2.0. The intact shear strength measured with the vane shear test range from 50 kPa to 87 kPa. The clay exhibits a strain-softening behaviour (a loss of about 40 % of its peak shear strength) during undrained shear tests. A quasi-horizontal failure surface with two main levels was identified by mean of the piezocone tests done inside the scar. The High safety factors obtained by the stability analysis performed with limit equilibrium methods show that the retrogression cannot be explained by conventional analysis methods. In the second part of this thesis, the numerical application of progressive failure was applies to the Casselman (1971) case and the Saint-Luc-de-Vincennes (1986) case. A parametric study was realized in order to assess the influence of the post-peak behaviour brittleness of the soil, related in this study to a shear band thickness, and the large deformation strength on the initiation and the retrogression of progressive failure process. The 1971 and 1986 cases were analysed with the finite element program BIFURC. The results demonstrated that the large deformation strength has a very low effect on the initiation of progressive failure process, and the initiation of the failure is mostly influenced by the brittleness behaviour of the soil. It was also observed that the retrogression of the failure is mostly controlled by the large deformation strength.|
|Document Type:||Mémoire de maîtrise|
|Open Access Date:||24 April 2018|
|Collection:||Thèses et mémoires|
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