Effects of Grain Scale Heterogeneity on Rock Strength and the Chipping Process
Publication: International Journal of Geomechanics
Volume 12, Issue 6
Abstract
Heterogeneity is an important factor controlling fracture initiation, accumulation, and propagation within polycrystalline rock. Internal spatial variability in terms of mineralogy, grain size, and anisotropy affect the yielding process. To investigate these factors, a texture-generating algorithm integrated within a numerical model was developed to create realistic rock analogs and provide user control over geological characteristics including mineral type, grain size, and anisotropic crystal shape. A mineral-specific constitutive model was created and calibrated using published values and real laboratory strength values. Brazilian tensile strength and unconfined compressive strength (UCS) model tests were developed using the finite-difference modeling software FLAC to perform parametric analysis of a series of geological characteristics. The results show that the methodology is capable of realistically reproducing damage propagation and failure behavior similar to that observed during laboratory testing. The strength results show trends similar to those found during laboratory testing. This methodology was applied to the simulation of tunnel-boring machine (TBM) cutter excavation to investigate the effect of geomechanical characteristics on the chipping process.
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Acknowledgments
Financial support was provided by Herrenknecht AG and a Postgraduate Scholarship from the Natural Science and Engineering Research Council (NSERC) of Canada.
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Information & Authors
Information
Published In
International Journal of Geomechanics
Volume 12 • Issue 6 • December 2012
Pages: 632 - 647
Copyright
© 2012 American Society of Civil Engineers.
History
Received: Mar 29, 2011
Accepted: Nov 22, 2011
Published online: Nov 24, 2011
Published in print: Dec 1, 2012
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