Research on mechanical properties of heterogeneous rocks using grain-based model under uniaxial compression

被引：0
|
作者：
Liu L.-W. [1 ,2 ]
Li H.-B. [1 ,2 ]
Li X.-F. [1 ]
Zhang G.-K. [3 ]
Wu R.-J. [1 ,2 ]
机构：
[1] State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan
[2] University of Chinese Academy of Science, Beijing
[3] School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing
来源：
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | 2020年 / 42卷 / 03期
关键词：
Acoustic emission; Discrete element method; Grain-based model; Grain-scale crack; Heterogeneous rock;
D O I：
10.11779/CJGE202003016
中图分类号：
学科分类号：
摘要：
In order to investigate the influences of structural heterogeneity on the mechanical properties and crack growth of rocks, the microstructure of granite is modelled by using grain-based model (GBM). In comparison with the results of laboratory experiments, the properties of stress-strain curves, acoustic emission and grain-scale crack growth of rocks with different mineralogies are investigated. The results show that GBM can be used to efficiently study the macro- and micro-mechanical properties of rocks when the mineral components have different structures and strengths. The grain-scale cracks in rocks are mainly intergranular cracks at the onset of loading, then the intragranular cracks become predominant inversely, and the failure pattern of cracks is always dominated by tensile cracks. When the model fails, the ratios of intergranular and intragranular cracks to total cracks are about 93.87% and 60.95%, respectively. During the whole loading, the locations of microcracks are first located randomly, then the clustering of microcracks leads to the appearance of macroscopic failure surface, and the formation of failure surface is related to the propagation and coalescence of intragranular cracks. When the feldspar mineral in rocks increases, the corresponding peak stress and damage stress increase due to the increase of intragranular cracks formed in feldspar mineral and the decrease of intragranular cracks formed in biotite mineral. In this study, the modelling of micro-structure based on GBM and the reason why heterogeneous rocks behave different mechanical properties may promote our understanding of the influences of rock heterogeneity on the mechanical properties. © 2020, Editorial Office of Chinese Journal of Geotechnical Engineering. All right reserved.
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页码：542 / 550
页数：8
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