Modelling approaches considering impacts of water-level fluctuations on slope stability
2014 (English)In: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 4, no 4, 17-34 p.Article in journal (Refereed) Published
Waterfront slopes are affected by water-level fluctuations originating from as well natural sources (e.g. tides and wind waves), as non-natural sources such as watercourse regulation involving daily or hourly recurring water-level fluctuations. Potentially instable slopes in populated areas means risks for as well property as human lives. In this study, three different approaches used for hydro-mechanical coupling in FEM-modelling of slope stability, have been evaluated. A fictive slope consisting of a till-like soil material has been modeled to be exposed to a series of water-level fluctuation cycles (WLFC’s). Modelling based on assuming fully saturated conditions, and with computations of flow and deformations separately run, has been put against two approaches being more sophisticated, with unsaturated-soil behavior considered and with computations of pore-pressures and deformations simultaneously run. Development of stability, vertical displacements, pore pressures, flow, and model-parameter influence, has been investigated for an increased number of WLFC’s. It was found that more advanced approaches did allow for capturing larger variations of flow and pore pressures. Classical modelling resulted in smaller vertical displacements, and smoother development of pore-pressure and flow. Flow patterns, changes of soil density (linked to volume changes governed by suction fluctuations), and changes of hydraulic conductivity, are all factors governing as well water-transport (e.g. efficiency of dissipation of excess pore pressures) as soil-material transport (i.e. susceptibility to internal erosion to be initiated and/or continued). Therefore, the results shown underline potential strengths of sophisticated modelling. Parameter influence was shown to change during water-level cycling.
Place, publisher, year, edition, pages
2014. Vol. 4, no 4, 17-34 p.
Research subject Soil Mechanics
IdentifiersURN: urn:nbn:se:ltu:diva-16292Local ID: feab3b1c-de87-415c-8bea-3d74c9eb9c53OAI: oai:DiVA.org:ltu-16292DiVA: diva2:989268
Validerad; 2014; 20140630 (johjen)2016-09-292016-09-29Bibliographically approved