Anisotropy of strength and deformability of fractured rocks
2014 (English)In: Journal of Rock Mechanics and Geotechnical Engineering, ISSN 1674-7755, Vol. 6, no 1, 156-164 p.Article in journal (Refereed) Published
Anisotropy of the strength and deformation behaviors of fractured rock masses is a crucial issue fordesign and stability assessments of rock engineering structures, due mainly to the non-uniform and nonregulargeometries of the fracture systems. However, no adequate efforts have been made to study thisissue due to the current practical impossibility of laboratory tests with samples of large volumes containingmany fractures, and the difficulty for controlling reliable initial and boundary conditions forlarge-scale in situ tests. Therefore, a reliable numerical predicting approach for evaluating anisotropy offractured rock masses is needed. The objective of this study is to systematically investigate anisotropy ofstrength and deformability of fractured rocks, which has not been conducted in the past, using a numericalmodeling method. A series of realistic two-dimensional (2D) discrete fracture network (DFN)models were established based on site investigation data, which were then loaded in different directions,using the code UDEC of discrete element method (DEM), with changing confining pressures. Numericalresults show that strength envelopes and elastic deformability parameters of tested numerical modelsare significantly anisotropic, and vary with changing axial loading and confining pressures. The resultsindicate that for design and safety assessments of rock engineering projects, the directional variations ofstrength and deformability of the fractured rock mass concerned must be treated properly with respectto the directions of in situ stresses. Traditional practice for simply positioning axial orientation of tunnelsin association with principal stress directions only may not be adequate for safety requirements.Outstanding issues of the present study and suggestions for future study are also presented.
Place, publisher, year, edition, pages
2014. Vol. 6, no 1, 156-164 p.
Anisotropy, Strength criterion, Deformation behavior, Numerical experiments, Fractured rock mass, Discrete element method (DEM), Discrete fracture network (DFN)
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-155712DOI: 10.1016/j.jrmge.2014.01.009ScopusID: 2-s2.0-84925287460OAI: oai:DiVA.org:kth-155712DiVA: diva2:762153
QC 201411112014-11-102014-11-102014-11-11Bibliographically approved