Critical hydraulic gradients for internally unstable cohensionless soils

M. Li

In the proceedings of: GeoVancouver 2016: 69th Canadian Geotechnical Conference

Session: FUNDAMENTALS - VII Soil & Rock Mechanics

ABSTRACT: Internal erosion can occasionally occur in potentially internally unstable soils that are subject to seepage flow, for example in earthfill dams or other soil structures. The migrations of finer particles within the soil are controlled by geometric characteristics such as grain size distribution, density, grain shape, and also by hydrodynamic characteristics such as seepage and effective stress. In this paper, the onset of internal stability is examined based on experimental tests. A relation was establishenormalized hydraulic gradient) and pore size of a soil. Furthermore, the critical hydraulic gradient to trigger internal instability in an unstable soil is estimated based on its grain size distribution curve. The contribution of the work is to validate improved empirical methods for use as screening tools in engineering practice.

RÉSUMÉ: L'érosion interne peut parfois se produire dans les sols potentiellement instables dans leur structure interne qui sont soumis à l'écoulement des eaux d'infiltration, par exemple dans les barrages en remblai ou d'autres structures de sol. Les migrations de particules plus fines dans le sol sont contrôlées par des caractéristiques géométriques telles que la distribution de la taille des grains, la densité, la forme du grain, et aussi par les caractéristiques hydrodynamiques telles ssais expérimentaux. Une relation a été établie entre l' de Skempton et Brogan (le gradient hydraulique normalisé) et la taille des pores d'un sol. En outre, le gradient hydraulique critique pour déclencher l'instabilité interne dans un sol instable est estimé en fonction de sa courbe de distribution granulométrique. La contribution du travail est de valider des méthodes

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Cite this article:
M. Li (2016) Critical hydraulic gradients for internally unstable cohensionless soils in GEO2016. Ottawa, Ontario: Canadian Geotechnical Society.

@article{3720_0721104718,author = M. Li,title = Critical hydraulic gradients for internally unstable cohensionless soils,year = 2016}