Influence of microscopic characteristics on the anisotropy of crack initiation stress and crack propagation of schist

被引：0

作者：

Yin X. ^{[1
]}

Yan E. ^{[2
]}

Huang S. ^{[2
]}

Feng B. ^{[1
]}

Wang L. ^{[3
]}

机构：

[1] Faculty of Architecture and Civil Engineering, Xinyang Normal University, Xinyang, 464000, Henan

[2] Faculty of Engineering, China University of Geosciences(Wuhan), Wuhan, 430074, Hubei

[3] Faculty of Mining Engineering, Liaoning Shihua University, Fushun, 113001, Liaoning

来源：

Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | 2019年 / 38卷 / 07期

基金：

中国国家自然科学基金;

关键词：

Anisotropy; Crack initiation stress; Crack propagation; Micro factors; Quartz mica schist; Rock mechanics;

D O I：

10.13722/j.cnki.jrme.2018.1401

中图分类号：

学科分类号：

摘要：

The progressive failure of brittle schist with schistose planes shows anisotropy under compression loading. In order to study the anisotropic properties of crack initiation stress and crack propagation of schist and their correlations with micro factors, three types of quartz mica schist samples were selected. Firstly, the optical section analysis of these samples was carried out, and the differences among the characteristics of micro- fissures(pores) of three type samples were quantitatively analyzed. The results show that the mica minerals in the samples are easy to form heterogeneous layers by directional aggregation, and that the micro-fissures are mainly distributed along the edge of the mineral while the developmental direction of the defects in other parts is irregular. Then, uniaxial compression tests were performed on cylindrical specimens with different schistose angles, and the failure morphology and stress-strain curve characteristics of the specimens were investigated. Theoretical analysis of fracture mechanics shows that, when the compression loading is oblique to(α=30°) and perpendicular to (α=90°) the heterogeneous layer, the initiation of rock fracture is respectively controlled by the directional micro-fissures and the irregular micro-fissures(pores) with dominant angles. The guiding and promoting effect of the weak edge of directionally aggregated minerals on crack growth is closely dependent on the loading direction, which results in the difference of macro shear failure modes of specimens with different schistose angles. Statistical analysis results of stress and strain data as well as the data reflecting micro properties show that the initiation stress and the initiation stress level of specimens have good regularity, which is related to the heterogeneity of rocks and the characteristics of micro-fissures(pores) such as distribution, quantity, size and nature. © 2019, Science Press. All right reserved.

引用

页码：1373 / 1384

页数：11

共 28 条

[1]

Brace W.F., Paulding B.R., Scholz C., Dilatancy in fracture of crystalline rocks, Journal of Geophysical Research, 71, 16, pp. 3939-3953, (1966)

[2]

Bieniawski Z.T., Mechanism of brittle fracture of rock: part I-theory of the fracture process, International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts, 4, 4, pp. 395-406, (1967)

[3]

Martin C.D., The effect of cohesion loss and stress path on brittle rock strength, Canadian Geotechnical Journal, 34, 5, pp. 698-725, (1997)

[4]

Eberhardt E., Stead D., Stimpson B., Et al., Identifying crack initiation and propagation thresholds in brittle rock, Canadian Geotechnical Journal, 35, 2, pp. 222-233, (1998)

[5]

Nicksiar M., Martin C.D., Evaluation of methods for determining crack initiation in compression tests on low-porosity rocks, Rock Mechanics and Rock Engineering, 45, 4, pp. 607-617, (2012)

[6]

Zhou H., Meng F., Lu J., Et al., Discussion on methods for calculating crack initiation strength and crack damage strength for hard rock, Rock and Soil Mechanics, 35, 4, pp. 913-918, (2014)

[7]

Erdogan F., Sih G.C., On crack extension in plates under plane loading and transverse shear, Journal of Basic Engineering, ASME, 85, 4, pp. 519-527, (1963)

[8]

Fan J., He J., Strength characteristics of rock mass with directional closed intermittent joints, Chinese Journal of Rock Mechanics and Engineering, 11, 2, pp. 190-199, (1992)

[9]

He J., Fan J., Strength characteristics of brittle rock mass with a group of uninterrupted intermittent joints, Journal of Sichuan University: Engineering Science, 54, 6, pp. 57-64, (1990)

[10]

Liu Q., Wei L., Liu X., Et al., A revised empirical method for predicting crack initiation based on Griffith strength criterion, Chinese Journal of Rock Mechanics and Engineering, 36, 7, pp. 1561-1569, (2017)

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