Structural changes in shear zones and slide planes of clays with different types of structural bonds

  • Anguelov K. 
  • Anguelova R. 
  • Lakov A. 


The study of shear zones and slide planes leads to the detailed characterization of the deformation process which depends mainly on the type of structural bonds between the particles. The results obtained by using a scanning electron microscope, show that the thickness of the zone of oriented clay minerals when shearing clays with phase contacts, is about 20–60 μm, while in clays with predomination of atomic (point) contacts is 30–150 μm. Almost the same thickness of this zone is observed in separate shear planes, forming one slide surface. In clays with close coagulation contacts the same zones have a different character and thickness, while in silts with distant coagulation contacts such zones are not observed.


Clay Shear Zone Shear Plane Phase Contact Structural Bond 

Modification des structures dans les zones de cisaillement et les surfaces de glissement dans les argiles en fonction des types de liaisons


L'étude des zones de cisaillement et des surfaces de glissement de différents types d'argiles conduit à une description détaillée du processus de déformation, qui dépend principalement du type de liaisons structurales entre les particules. L'examen au microscope à balayage montre qu'en cas de cisaillement l'épaisseur de la zone à minéraux argileux orientés est comprise entre 20 et 60 μm, en cas de “contacts d'agrégats de particules”, alors qu'elle est comprise entre 30 et 150 μm lorsqu'il y a prédominance de “contacts atomiques” (“ponctuels”). On observe à peu près les mêmes épaisseurs sur des zones de cisaillement séparées formant une seule surface de glissement. Dans les argiles où existent des “contacts de floculation”, les mêmes zones présentent des caractères et des épaisseurs différents, tandis que dans les silts à “contacts de floculation” éloignés ces zones n'existent pas.


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Copyright information

© International Association of Engineering Geology 1983

Authors and Affiliations

  • Anguelov K. 
    • 1
  • Anguelova R. 
    • 2
  • Lakov A. 
    • 1
  1. 1.Higher Institute of Mining and GeologySofiaBulgaria
  2. 2.Geomechanical Laboratory BAScSofiaBulgaria

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