Study of shear resistance and anisotropy of layered shales.

Characterizing anisotropy remains challenging in rock mechanics. Particularly, the strengths and failure patterns of layered shales under shear load are significantly anisotropic mainly because of the bedding planes. Meanwhile, understanding the creation and propagation of shear fractures is critica...

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Main Authors: Min Gao, Bin Gong, Zhengzhao Liang, Shanpo Jia, Xianhui Feng
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2024-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0313134
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author Min Gao
Bin Gong
Zhengzhao Liang
Shanpo Jia
Xianhui Feng
author_facet Min Gao
Bin Gong
Zhengzhao Liang
Shanpo Jia
Xianhui Feng
author_sort Min Gao
collection DOAJ
description Characterizing anisotropy remains challenging in rock mechanics. Particularly, the strengths and failure patterns of layered shales under shear load are significantly anisotropic mainly because of the bedding planes. Meanwhile, understanding the creation and propagation of shear fractures is critical for drilling, mining, tunnelling, exploitation of shale gas, etc. In this study, the shear resistance of layered shales is comprehensively investigated based on the direct shear tests numerically. The results show that the shear parameters are greatly affected by the anisotropy induced by the normal stress and orientation of bedding planes; the shear strength, cohesion and internal friction angle generally increase with the growth of bedding plane orientation. Furthermore, three shear failure patterns are summarized, i.e., (1) the shear failure along bedding planes; (2) the shear failure crossing bedding planes; (3) the combination of tensile failure along bedding planes and shear failure crossing bedding planes. Besides, the empirical fitting formula characterizing the shear strength of layered rocks under triaxial compression is provided, and the modified Mohr-Coulomb criterion reflecting rock anisotropy is proposed.
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institution OA Journals
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publishDate 2024-01-01
publisher Public Library of Science (PLoS)
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spelling doaj-art-3dbd3acd99d84a05aa0d1c08ad22a5ee2025-08-20T02:21:52ZengPublic Library of Science (PLoS)PLoS ONE1932-62032024-01-011912e031313410.1371/journal.pone.0313134Study of shear resistance and anisotropy of layered shales.Min GaoBin GongZhengzhao LiangShanpo JiaXianhui FengCharacterizing anisotropy remains challenging in rock mechanics. Particularly, the strengths and failure patterns of layered shales under shear load are significantly anisotropic mainly because of the bedding planes. Meanwhile, understanding the creation and propagation of shear fractures is critical for drilling, mining, tunnelling, exploitation of shale gas, etc. In this study, the shear resistance of layered shales is comprehensively investigated based on the direct shear tests numerically. The results show that the shear parameters are greatly affected by the anisotropy induced by the normal stress and orientation of bedding planes; the shear strength, cohesion and internal friction angle generally increase with the growth of bedding plane orientation. Furthermore, three shear failure patterns are summarized, i.e., (1) the shear failure along bedding planes; (2) the shear failure crossing bedding planes; (3) the combination of tensile failure along bedding planes and shear failure crossing bedding planes. Besides, the empirical fitting formula characterizing the shear strength of layered rocks under triaxial compression is provided, and the modified Mohr-Coulomb criterion reflecting rock anisotropy is proposed.https://doi.org/10.1371/journal.pone.0313134
spellingShingle Min Gao
Bin Gong
Zhengzhao Liang
Shanpo Jia
Xianhui Feng
Study of shear resistance and anisotropy of layered shales.
PLoS ONE
title Study of shear resistance and anisotropy of layered shales.
title_full Study of shear resistance and anisotropy of layered shales.
title_fullStr Study of shear resistance and anisotropy of layered shales.
title_full_unstemmed Study of shear resistance and anisotropy of layered shales.
title_short Study of shear resistance and anisotropy of layered shales.
title_sort study of shear resistance and anisotropy of layered shales
url https://doi.org/10.1371/journal.pone.0313134
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AT bingong studyofshearresistanceandanisotropyoflayeredshales
AT zhengzhaoliang studyofshearresistanceandanisotropyoflayeredshales
AT shanpojia studyofshearresistanceandanisotropyoflayeredshales
AT xianhuifeng studyofshearresistanceandanisotropyoflayeredshales