Effects of scale and normal stress on shear behavior of a soft fracture replica

Giwelli, A. A., Gumati, A., Sakaguchi, K. and Matsuki, K. (2014) Effects of scale and normal stress on shear behavior of a soft fracture replica. Geotechnical and Geological Engineering, 32 3: 673-686. doi:10.1007/s10706-014-9743-x


Author Giwelli, A. A.
Gumati, A.
Sakaguchi, K.
Matsuki, K.
Title Effects of scale and normal stress on shear behavior of a soft fracture replica
Journal name Geotechnical and Geological Engineering   Check publisher's open access policy
ISSN 0960-3182
1573-1529
Publication date 2014-06
Year available 2014
Sub-type Article (original research)
DOI 10.1007/s10706-014-9743-x
Open Access Status
Volume 32
Issue 3
Start page 673
End page 686
Total pages 14
Place of publication Dordrecht, Netherlands
Publisher Springer Netherlands
Collection year 2015
Language eng
Abstract The effects of the fracture scale (size) and normal stress on the shear behavior of a fracture were investigated in direct shear rig using mortar fracture replicas of different sizes (100-200 mm), which were reproduced from a tensile fracture created in granite. Monotonic shear loading was applied at normal stresses of 0.3 and 1 MPa for shear displacements of 2 and 20 mm. The change in surface topography was measured by using a profile measurement system with a laser profilometer to determine the changes in surface damage and the aperture during shear. Additionally, the effect of gouge material on the non-linearity of the closure curve during shear was investigated. The results show that the standard deviation of the initial aperture during shear increases not only with scale but also with the normal stress, since the matedness decreases due to the fact that asperities are more damaged with normal stress, and accordingly, the non-linearity in the closure curve during shear increases with normal stress. The results also show that the non-linearity of the closure curve during shear increases with the presence of gouge material/debris that is produced in the shearing process. This is mainly because gouge is soft and easily deforms under the application of normal stress. Moreover, gouge material is distributed non-uniformly around the contact areas. Thus, the normal stiffness during shear decreases not only with a decrease in the matedness between the surfaces, but also with the presence of gouge material.
Keyword Mortar replica
Aperture
Fracture size
Normal and shear stresses
Closure
Gouge material
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Chemical Engineering Publications
Official 2015 Collection
 
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Created: Tue, 27 May 2014, 02:43:48 EST by System User on behalf of School of Chemical Engineering