含节理层状类岩石在单轴压缩下裂纹的定量识别研究  

Quantitative Identification of Cracks in Jointed Layered Rock Specimens under Uniaxial Compression

作　　者：汪学清[1] 赵云猛 汪壮壮 陈博 董泽 吴帅军 WANG Xueqing;ZHAO Yunmeng;WANG Zhuangzhuang;CHEN Bo;DONG Ze;WU Shuaijun(School of Mechanics and Civil Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)力学与建筑工程学院,北京100083

出　　处：《矿业研究与开发》2023年第6期127-133,共7页Mining Research and Development

基　　金：深海矿产资源开发利用技术国家重点实验室开放课题(2021-HYSDDYB-001).

摘　　要：为研究复合岩层在单轴压缩下裂纹扩展机理和破坏模式,通过数字图像相关方法(DIC)观测单轴压缩下含预制节理的层状类岩石试件裂纹走向和应变场变化,引入协方差矩阵对节理倾角分别为0°、15°、30°、45°、60°、75°的试件应变场离散性进行量化,经过分析得到:(1)用新的方法对裂纹两侧点位的位移数据量化处理,判别裂纹类型为拉伸裂纹(Ⅰ型)、剪切裂纹(Ⅱ型)和拉剪复合裂纹(Ⅰ-Ⅱ型);(2)基于协方差矩阵得到的参数V可表征裂纹起裂和扩展过程,V增长速率与裂纹发育的充分程度有较强相关性;(3)根据V的增长速率识别裂纹类型分别为:拉伸裂纹(0.12×10^(-4)~0.49×10^(-4))、剪切裂纹(1.17×10^(-4)~4.5×10^(-4))、拉剪复合裂纹(0.72×10^(-4)~0.99×10^(-4))。In order to study the crack propagation mechanism and failure mode of composite rock strata under uniaxial compression,the crack strike and strain field change of layered rock-like specimens with prefabricated joints under uniaxial compression were observed by digital image correlation method(DIC).The covariance matrix was introduced to quantify the strain field dispersion of specimens with joint dip angles of 0°,15°,30°,45°,60°,and 75°.The results show that the new method can be used to quantify the displacement data of the two sides of the crack,and the crack types are identified as tensile crack(TypeⅠ),shear crack(TypeⅡ),and composite tension-shear crack(TypeⅠ-Ⅱ).The parameter Vobtained based on the covariance matrix can characterize the crack initiation and propagation process,and the growth rate of V has a strong correlation with the sufficient degree of crack development.According to the growth rate of V,the crack types are identified as tensile crack(0.12×10^(-4)0.49×10^(-4)),shear crack(1.17×10^(-4)4.5×10^(-4)),and composite tensile-shear crack(0.72×10^(-4)0.99×10^(-4)).

关 键 词：复合岩层 DIC 裂纹类型 裂纹定量 协方差矩阵 

分 类 号：TD313.5[矿业工程—矿井建设] TU458.4[建筑科学—岩土工程]