Documents disponibles écrits par cet auteur

Assumptions in simplified slope stability analysis by the method of slices / I. M. Morrison in Géotechnique, Vol. 39 N°3 (Septembre 1989) 

Public ISBD [article]  in Géotechnique > Vol. 39 N°3 (Septembre 1989) . - pp. 503 –509 Titre : Assumptions in simplified slope stability analysis by the method of slices Type de document : texte imprimé Auteurs : I. M. Morrison, Auteur ; J. R. Greenwood, Auteur Année de publication : 2007 Article en page(s) : pp. 503 –509 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Stability  Pore  pressures  Analysis  Limit  state  design  Strains  Slopes Résumé : Several widely used methods of slope stability analysis are examined and their equations of stability are rearranged so as to demonstrate the physical assumptions underlying the methods. All the methods considered are shown to be based on a common assumption of no strain on the inter-slice boundaries. In addition it is shown that each method implies a particular assumption as to the pore water pressures acting on the inter-slice boundaries. A basic simplified slope stability equation is presented and used to compare the effect of the various pore water assumptions on the calculated factor of safety by reference to a real landslide in which the pore-water distribution in the slope was measured. It is shown that none of the assumed distributions correspond to the observed pore-water pressures. In the methods of analysis which compute the factor of safety more accurately the difference between the assumed and observed pore water pressures acts so as to increase the normal pressure on the slip surface and this compensates to some extent for the assumption of no strain within the slope. It is concluded that there is no theoretical reason for the extent of this compensation and that the use of simplified methods of analysis is only justified for slopes with geometry, soil strengths and pore water pressures similar to those against which the method has been calibrated. If these conditions are not satisfied the implied inter-slice forces should be checked. ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.1989.39.3.503 [article] Assumptions in simplified slope stability analysis by the method of slices [texte imprimé] / I. M. Morrison, Auteur ; J. R. Greenwood, Auteur . - 2007 . - pp. 503 –509. Génie Civil Langues : Anglais (eng) in Géotechnique > Vol. 39 N°3 (Septembre 1989) . - pp. 503 –509 Mots-clés : Stability  Pore  pressures  Analysis  Limit  state  design  Strains  Slopes Résumé : Several widely used methods of slope stability analysis are examined and their equations of stability are rearranged so as to demonstrate the physical assumptions underlying the methods. All the methods considered are shown to be based on a common assumption of no strain on the inter-slice boundaries. In addition it is shown that each method implies a particular assumption as to the pore water pressures acting on the inter-slice boundaries. A basic simplified slope stability equation is presented and used to compare the effect of the various pore water assumptions on the calculated factor of safety by reference to a real landslide in which the pore-water distribution in the slope was measured. It is shown that none of the assumed distributions correspond to the observed pore-water pressures. In the methods of analysis which compute the factor of safety more accurately the difference between the assumed and observed pore water pressures acts so as to increase the normal pressure on the slip surface and this compensates to some extent for the assumption of no strain within the slope. It is concluded that there is no theoretical reason for the extent of this compensation and that the use of simplified methods of analysis is only justified for slopes with geometry, soil strengths and pore water pressures similar to those against which the method has been calibrated. If these conditions are not satisfied the implied inter-slice forces should be checked. ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.1989.39.3.503