Influence of structural heterogeneities and of large scale topography on imbricate gravitational rock slope failures: New insights from 3-D physical modeling and geomorphological analysis

Détails

ID Serval
serval:BIB_4CFBE55DF1BC
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Influence of structural heterogeneities and of large scale topography on imbricate gravitational rock slope failures: New insights from 3-D physical modeling and geomorphological analysis
Périodique
Tectonophysics
Auteur(s)
Bois T., Bouissou S., Jaboyedoff M.
ISSN-L
0040-1951
Statut éditorial
Publié
Date de publication
2012
Peer-reviewed
Oui
Volume
526-529
Pages
147-156
Langue
anglais
Notes
Bois2012
Résumé
Initial topography and inherited structural discontinuities are known
to play a dominant role in rock slope stability. Previous 2-D physical
modeling results demonstrated that even if few preexisting fractures
are activated/propagated during gravitational failure all of those
heterogeneities had a great influence on mobilized volume and its
kinematics. The question we address in the present study is to determine
if such a result is also observed in 3-D. As in 2-D previous models
we examine geologically stable model configuration, based upon the
well documented landslide at Randa, Switzerland. The 3-D models consisted
of a homogeneous material in which several fracture zones were introduced
in order to study simplified but realistic configurations of discontinuities
(e.g. based on natural example rather than a parametric study). Results
showed that the type of gravitational failure (deep-seated landslide
or sequential failure) and resulting slope morphology evolution are
the result of the interplay of initial topography and inherited preexisting
fractures (orientation and density). The three main results are i)
the initial topography exerts a strong control on gravitational slope
failure. Indeed in each tested configuration (even in the isotropic
one without fractures) the model is affected by a rock slide, ii)
the number of simulated fracture sets greatly influences the volume
mobilized and its kinematics, and iii) the failure zone involved
in the 1991 event is smaller than the results produced by the analog
modeling. This failure may indicate that the zone mobilized in 1991
is potentially only a part of a larger deep-seated landslide and/or
wider deep seated gravitational slope deformation.
Mots-clé
rockslide movements, randa, fractures, physical modeling
Création de la notice
25/11/2013 16:26
Dernière modification de la notice
20/08/2019 14:01
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