Abstract:In 1994, a landslide occurred in the municipality of Sainte-Monique, Quebec. The debris of the landslide had graben and host shapes, typical of spreads in sensitive clays. The geotechnical investigation shows that the soil involved is a firm to stiff, sensitive, nearly normally consolidated grey silty clay of high plasticity. This soil exhibits a high sensitivity and a high brittleness during shear and is therefore susceptible to progressive failure. Traditional stability analysis cannot explain this landslide. This gives the opportunity to examine the applicability of progressive failure analysis to this spread. Using the finite elements method, it is demonstrated that the initiation and observed extent of the failure surface are explained by a soil having high brittleness during shear and a large-deformation shear strength close to the remoulded shear strength of the soil. The dislocation of the soil mass can also be explained by the active failure occurring in the soil mass above the failure surface during or shortly after failure propagation. It is therefore numerically demonstrated that progressive failure explains the initiation and the extent of the failure surface of this spread.Key words: progressive failure, spread, sensitive clay, large-deformation shear strength, brittleness.Résumé : Un glissement de terrain est survenu en 1994 dans la municipalité de Sainte-Monique, Québec. Les débris présentaient des formes de horsts et grabens typiques des étalements dans les argiles sensibles. L'investigation géotechnique démontre que le sol impliqué dans ce glissement est une argile silteuse grise normalement consolidée, sensible, de forte plasticité et ayant une consistance ferme à raide. Ce sol présente une sensibilité et une fragilité lors du cisaillement élevées et peut donc être susceptible à la rupture progressive. Les analyses de stabilité traditionnelles n'arrivent pas à expliquer ce glissement. Ceci offre donc l'opportunité d'examiner l'application du concept de la rupture progressive sur cet étalement. À l'aide de programmes d'éléments finis, il est démontré que l'initiation et l'étendue de la surface de rupture observée peuvent être expliquées par un sol ayant une grande fragilité lors du cisaillement et une résistance à grandes déformations près de la résistance du sol remanié. La dislocation de la masse de sol en horsts et grabens est expliquée par la rupture active survenant dans la masse de sol au-dessus de la surface de rupture pendant ou peu après la propagation de la rupture. Il est donc démontré numériquement que la rupture progressive explique l'initiation et l'étendue de la surface de rupture d'un étalement.
The Government of Québec recently initiated the deployment of a vast groundwater pressures monitoring network in postglacial marine clays to document their variations in time and improve our understanding of the relationship between failure initiation and climate in clay slopes. This project aims at evaluating the impacts of climate change on clay-slope stability and how it can be integrated in landslide risk management to improve public safety. Hydrogeological data will be acquired at sites located throughout the Québec Province's post-glacial clay deposits to create a public georeferenced index of typical hydrogeological conditions. The project goes beyond the characterization of groundwater pressures and their variations in clay slopes. Indeed, slope deformation will be measured at several sites. Also, two sites in flat terrain will be instrumented in order to evaluate mechanical properties of clay layers in simple 1-D conditions and groundwater recharge. The unsaturated clay crust in slopes susceptible to superficial landslides will be characterized and instrumented. The current lifetime of the monitoring project has been set to a period of 25 years.
With the growth of the insect farming industry, increasing quantities of insect manure (called frass) must be upcycled. This research provides one of the first sources of information regarding the potential plant growth enhancement of Tenebrio molitor's frass on garden plants. It aims at demonstrating that frass is a promising fertilizer for plant production. Nine vegetables, one herb, and three flowers were planted on the roof of "La Centrale Agricole" in Montreal. Plants were grown in a 5% compost-enriched substrate (v/v) (control) and fertilized with 0.5% (v/v) frass (treatment 2) or an isonitrogen concentration of hen manure (treatment 3). Plant growth (germination, height, N flowers) and productivity (biomass) were assessed regularly throughout the growing season. Although beets and carrots' seedling emergence was inhibited by both manures, this did not lead to reduced edible biomass compared to the control (germination was unaffected for corn, radish, and arugula). Similar to hen manure, frass resulted in a 16-fold increase of the edible biomass as compared to the control. Frass-fertilized plants had larger and more numerous flowers than control plants. Our results confirm that insect manure should be recognized as a suitable fertilizer for multiple crops, and should be regulated like other manures.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.