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Numerical studies on the failure process and associated microseismicity in rock under triaxial compression

Citation

Liu, H and Kou, SQ and Lindqvist, PA and Tang, CA, Numerical studies on the failure process and associated microseismicity in rock under triaxial compression, Tectonophysics: International Journal of Geotectonics and The Geology and Physics of The Interior of The Earth, 384, (1-4) pp. 149-174. ISSN 0040-1951 (2004) [Refereed Article]

DOI: doi:10.1016/j.tecto.2004.03.012

Abstract

In this paper, firstly the mesoscopic elemental mechanical model for elastic damage is developed and implemented into the rock and tool interaction code (R-T2D). Then the failure processes of a heterogeneous rock specimen subjected to a wide variety of confining pressures (0-80 MPa) are numerically investigated using the R-T2D code. According to the simulated results, on the one hand, the numerical simulation reproduced some of the well-known phenomena observed by previous researchers in triaxial tests. Under uniaxial compression, rock failure is caused by a combination of axial splitting and shearing. Dilatancy and a post-failure stage with a descending load bearing capacity are the prominent characteristics of the failure. As the confining pressure increases, the extension of the failed sites is suppressed, but the individual failure sites become dense and link with each other to form a shear fracture plane. Correspondingly, the peak strength, the residual strength and the shear fracture plane angle increase, but the brittleness decreases. When the confining pressure is high enough, the specimen behaves in a plastic manner and a narrow shear fracture plane leads to its failure. The prominent characteristics are volume condensation, ductile cataclastic failure, and a constant load bearing capacity with increasing strain. On the other hand, the numerical simulation revealed some new phenomena. The highest microseismicity events occur in the post-failure stage instead of the maximal stress, and most of the microseismicity energies are released in the failure localization process. As the confining pressure increases, the microseismicity events in the non-linear deformation stage increase dramatically and the ratio between the energies dissipated at the non-linear deformation stage and those dissipated in the whole loading process increases correspondingly. Therefore, it is concluded that the developed mesoscopic elemental mechanical model for elastic damage is able to reproduce accurately the failure characteristics in loading rock specimens under triaxial conditions, and the numerical modelling can furthermore obtain some new clarifications of the rock fracture process. © 2004 Elsevier B.V. All rights reserved.

Item Details

Item Type:Refereed Article
Research Division:Engineering
Research Group:Resources Engineering and Extractive Metallurgy
Research Field:Geomechanics and Resources Geotechnical Engineering
Objective Division:Construction
Objective Group:Construction Processes
Objective Field:Civil Construction Processes
Author:Liu, H (Dr Hong Liu)
ID Code:63518
Year Published:2004
Web of Science® Times Cited:34
Deposited By:Engineering
Deposited On:2010-05-11
Last Modified:2011-08-01
Downloads:0

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