Micromechanics of compressive failure and spatial evolution of anisotropic damage in Darley Dale sandstone

	Micromechanics of compressive failure and spatial evolution of anisotropic damage in Darley Dale sandstone
	Wu, XY ; Baud, P ; Wong, TF
刊名	INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
	2000
卷号	37 期号:1-2 页码:143-160
ISSN号	1365-1609
文献子类	Article
英文摘要	The micromechanics of compressive failure in Darley Dale sandstone (with initial porosity of 13%) was investigated by characterizing quantitatively the spatial evolution of anisotropic damage under the optical and scanning electron microscopes. Two series of triaxial compression experiments were conducted at the fixed pore pressure of 10 MPa and confining pressures of 20 and 210 MPa, respectively. For each series, three samples deformed to different stages were studied. Failure in the first series was by brittle faulting. In contrast, failure in the second series was ductile, involving shear-enhanced compaction and distributed cataclastic flow. In the ductile series, crack density and acoustic emission activity both increased with the development of strain hardening. The stress-induced cracking was relatively isotropic. In the brittle series, crack density increased with the progressive development of dilatancy, with spatial distributions indicative of clustering of damage at the peak stress and shear localization in the strain softening stage. Dilatancy was associated with significant anisotropy in stress-induced cracking, that was primarily due to intragranular and intergranular cracking with a preferred orientation parallel to the maximum principal stress. Compared with published data for Westerly granite and San Marcos gabbro (with porosities of the order of 1%) and for Berea sandstone (with porosity of 21%), there is an overall trend for the stress-induced anisotropy tin a sample deformed to near the peak stress) to decrease with increasing porosity. The sliding wing crack model was adopted to analyze the evolution of anisotropic damage, using a friction coefficient and fracture toughness inferred from stress states at the onset of dilatancy. Significant discrepancy exists between the model prediction and microstructural data on stress-induced anisotropy, which is possibly due to limitations intrinsic to the microscopy technique as well as the sliding wing crack model. (C) 2000 Elsevier Science Ltd. All rights reserved.
WOS关键词	GEOMETRIC PROBABILITY APPROACH ; WESTERLY GRANITE ; CATACLASTIC FLOW ; BRITTLE SOLIDS ; POROUS ROCKS ; MICROCRACKING ; TRANSITION ; CRACKS ; PROPAGATION ; DEFORMATION
WOS研究方向	Engineering ; Mining & Mineral Processing
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000087457100019
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/75804]
专题	中国科学院地质与地球物理研究所
通讯作者	Wong, TF
作者单位	1.SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA 2.Chinese Acad Sci, Inst Geophys, Beijing 100101, Peoples R China
推荐引用方式 GB/T 7714	Wu, XY,Baud, P,Wong, TF. Micromechanics of compressive failure and spatial evolution of anisotropic damage in Darley Dale sandstone[J]. INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES,2000,37(1-2):143-160.
APA	Wu, XY,Baud, P,&Wong, TF.(2000).Micromechanics of compressive failure and spatial evolution of anisotropic damage in Darley Dale sandstone.INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES,37(1-2),143-160.
MLA	Wu, XY,et al."Micromechanics of compressive failure and spatial evolution of anisotropic damage in Darley Dale sandstone".INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES 37.1-2(2000):143-160.