Evolution law of strain field and precursor identification of flawed sandstone based on Digital Image Correlation method
-
摘要:
目前数字图像相关方法在岩石力学领域的应用主要集中于获取变形场云图，缺乏结合一些指标对变形数据进行定量分析。采用数字图像相关方法对裂隙砂岩试件压缩加载过程进行非接触式、实时变形测量，结合方差量化描述应变场分异特征；而后对应变场方差变化曲线进行有限差分求导，量化描述应变场分异速率，分析应变场演化规律及前兆特征。研究结果表明：裂隙砂岩试件的变形破裂过程可划分为压密、弹性变形、裂纹稳定扩展、裂纹快速扩展及破坏等4个阶段。加载过程中裂隙砂岩试件的裂纹萌生和扩展行为，在应变场上表现为应变局部化带的产生与发展，进而导致应变场方差和分异速率发生变化。应变场方差-轴向应变曲线表现出阶段性特征，可划分为稳定分异、加速分异以及加加速分异等3个阶段。应变场分异速率-轴向应变曲线在张拉裂纹起裂时均出现第一个尖峰，可作为裂隙岩体失稳破坏前的前兆信号，对应的前兆应力与峰值应力之比为0.80～0.96。研究成果对工程岩体失稳预测具有较好的理论参考价值。
Abstract:Previous studies on the application of Digital Image Correlation(DIC) method in rock mechanics have mainly focused on obtaining the contours of deformation fields, whereas little attention has been paid to perform quantitative analysis on these deformation data by combining some indicators. The digital image correlation method was applied for real-time and non-contact monitoring deformation of flawed sandstone specimens during the compressive loading process. The differentiation characteristic of strain field was quantitatively described by using the variance. The differentiation rate of strain field was quantitatively described by using the finite difference derivative of the variance variation curve. The evolution laws of strain field and precursor characteristics were analyzed. The results show that the deformation and fracturing process in flawed sandstone specimens can be divided into four stages, namely, compaction, elastic deformation, steady crack propagation, rapid crack propagation and failure. The crack initiation and propagation behavior during the loading process is associated with the generation and development of strain localization zones in the strain field, resulting in the variations of variance and differentiation rate of strain field. The evolution process of variance of strain field shows an obvious periodic characteristic. The variance of strain field-axial strain curve can be divided into three stages, namely, steady differentiation, accelerated differentiation and accelerated acceleration differentiation. When the tensile crack appears, the first peak occurs in the differential rate of the strain field-axial strain curve, which could be regarded as a precursor before the failure of fractured rock mass. The ratio of precursor stress to peak stress is in the ranges of 0.80～0.96. The research results have theoretical significance for the failure prediction of engineering rock mass.
-
Key words:
- sandstone /
- flaw /
- Digital Image Correlation method /
- strain field /
- fracturing /
- precursor
-
-
[1] 郭朋瑜, 吉锋, 何双, 等. 节理分布位置对岩体剪切破裂特征影响试验研究[J]. 水文地质工程地质,2019,46(3):81 − 87. [GUO Pengyu, JI Feng, HE Shuang, et al. An experimental study of the influence of discontinuous structural planes at different locations on the shear fracture characteristics of rock mass[J]. Hydrogeology & Engineering Geology,2019,46(3):81 − 87. (in Chinese with English abstract)
[2] 周洪福, 宋志, 李富, 等. 鸡公山斜坡岩体裂隙网络模拟及强度参数研究[J]. 水文地质工程地质,2016,43(3):153 − 158. [ZHOU Hongfu, SONG Zhi, LI Fu, et al. Research on fracture network simulation and parameters of shear strength of the Jigongshan slope[J]. Hydrogeology & Engineering Geology,2016,43(3):153 − 158. (in Chinese with English abstract)
[3] 李滨, 张青, 王文沛, 等. 金沙江乌东德水电站坝区高陡边坡地质灾害监测预警研究[J]. 地质力学学报,2020,26(4):556 − 564. [LI Bin, ZHANG Qing, WANG Wenpei, et al. Geohazard monitoring and risk management of high-steep slope in the Wudongde dam area[J]. Journal of Geomechanics,2020,26(4):556 − 564. (in Chinese with English abstract) doi: 10.12090/j.issn.1006-6616.2020.26.04.048
[4] 王军朝, 孙金辉. 川东红层缓倾角岩质崩塌特征与稳定性分析[J]. 地质力学学报,2019,25(6):1091 − 1098. [WANG Junchao, SUN Jinhui. Characteristics and stability analysis of rock collapse of low-angled red-bed slope in east Sichuan[J]. Journal of Geomechanics,2019,25(6):1091 − 1098. (in Chinese with English abstract)
[5] 赵洪宝, 胡桂林, 李伟, 等. 预制裂隙岩石裂纹扩展规律的研究进展与思考[J]. 地下空间与工程学报,2016,12(增刊2):899 − 906. [ZHAO Hongbao, HU Guilin, LI Wei, et al. Research progress and thinking on the crack propagation law of pre-fractured rock[J]. Chinese Journal of Underground Space and Engineering,2016,12(Sup2):899 − 906. (in Chinese with English abstract)
[6] WONG L N Y, EINSTEIN H H. Systematic evaluation of cracking behavior in specimens containing single flaws under uniaxial compression[J]. International Journal of Rock Mechanics and Mining Sciences,2009,46(2):239 − 249. doi: 10.1016/j.ijrmms.2008.03.006
[7] 曹平, 曹日红, 赵延林, 等. 岩石裂纹扩展-破断规律及流变特征[J]. 中国有色金属学报,2016,26(8):1737 − 1762. [CAO Ping, CAO Rihong, ZHAO Yanlin, et al. Propagation-coalescence and rheologic fracture behavior of rock cracks[J]. The Chinese Journal of Nonferrous Metals,2016,26(8):1737 − 1762. (in Chinese with English abstract)
[8] 杨圣奇, 戴永浩, 韩立军, 等. 断续预制裂隙脆性大理岩变形破坏特性单轴压缩试验研究[J]. 岩石力学与工程学报,2009,28(12):2391 − 2404. [YANG Shengqi, DAI Yonghao, HAN Lijun, et al. Uniaxial compression experimental research on deformation and failure properties of brittle marble specimen with pre-existing fissures[J]. Chinese Journal of Rock Mechanics and Engineering,2009,28(12):2391 − 2404. (in Chinese with English abstract) doi: 10.3321/j.issn:1000-6915.2009.12.003
[9] HUANG D, GU D M, YANG C, et al. Investigation on mechanical behaviors of sandstone with two preexisting flaws under triaxial compression[J]. Rock Mechanics and Rock Engineering,2016,49(2):375 − 399. doi: 10.1007/s00603-015-0757-3
[10] 赵洪辉, 靖洪文, 苏海健, 等. 含共面裂隙群砂岩强度与破裂特征的试验研究[J]. 工程力学,2015,32(2):183 − 189. [ZHAO Honghui, JING Hongwen, SU Haijian, et al. Strength and fracture characteristics of sandstone containing coplanar fissure group[J]. Engineering Mechanics,2015,32(2):183 − 189. (in Chinese with English abstract)
[11] YAMAGUCHI I. A laser-speckle strain gauge[J]. Journal of Physics E: Scientific Instruments,1981,14(11):1270 − 1273.
[12] PETER W H, RANSON W F. Digital image technique in experimental stress analysis[J]. Optical Engineering,1982,21(3):427 − 431.
[13] 马少鹏. 数字散斑相关方法在岩石破坏测量中的发展与应用[J]. 岩石力学与工程学报,2004,23(8):1410. [MA Shaopeng. Development and application of digital speckle correlation method of failure measurement for rock materials[J]. Chinese Journal of Rock Mechanics and Engineering,2004,23(8):1410. (in Chinese with English abstract) doi: 10.3321/j.issn:1000-6915.2004.08.034
[14] 宋义敏, 姜耀东, 马少鹏, 等. 岩石变形破坏全过程的变形场和能量演化研究[J]. 岩土力学,2012,33(5):1352 − 1356. [SONG Yimin, JIANG Yaodong, MA Shaopeng, et al. Evolution of deformation fields and energy in whole process of rock failure[J]. Rock and Soil Mechanics,2012,33(5):1352 − 1356. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-7598.2012.05.012
[15] 徐金明, 王强, 周廷文. 根据试验视频确定石灰岩中的位移场[J]. 水文地质工程地质,2010,37(2):70 − 75. [XU Jinming, WANG Qiang, ZHOU Tingwen. Displacement field of limestone using video images from laboratory tests[J]. Hydrogeology & Engineering Geology,2010,37(2):70 − 75. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-3665.2010.02.015
[16] 潘红宇, 葛迪, 张天军, 等. 应变率对岩石裂隙扩展规律的影响[J]. 煤炭学报,2018,43(3):675 − 683. [PAN Hongyu, GE Di, ZHANG Tianjun, et al. Influence of strain rate on the rock fracture propagation law[J]. Journal of China Coal Society,2018,43(3):675 − 683. (in Chinese with English abstract)
[17] 大久保诚介, 汤杨, 许江, 等. 3D-DIC系统在岩石力学试验中的应用[J]. 岩土力学,2019,40(8):3263 − 3273. [OKUBO Seisuke, TANG Yang, XU Jiang, et al. Application of 3D-DIC system in rock mechanic test[J]. Rock and Soil Mechanics,2019,40(8):3263 − 3273. (in Chinese with English abstract)
[18] TANG Y, OKUBO S, XU J, et al. Experimental study on damage behavior of rock in compression-tension cycle test using 3D digital image correlation[J]. Rock Mechanics and Rock Engineering,2019,52(5):1387 − 1394. doi: 10.1007/s00603-018-1685-9
[19] 袁媛, 潘鹏志, 赵善坤, 等. 基于数字图像相关法的含填充裂隙大理岩单轴压缩破坏过程研究[J]. 岩石力学与工程学报,2018,37(2):339 − 351. [YUAN Yuan, PAN Pengzhi, ZHAO Shankun, et al. The failure process of marble with filled crack under uniaxial compression based on digital image correlation[J]. Chinese Journal of Rock Mechanics and Engineering,2018,37(2):339 − 351. (in Chinese with English abstract)
[20] ZHOU X P, LIAN Y J, WONG L N Y, et al. Understanding the fracture behavior of brittle and ductile multi-flawed rocks by uniaxial loading by digital image correlation[J]. Engineering Fracture Mechanics,2018,199:438 − 460. doi: 10.1016/j.engfracmech.2018.06.007
[21] 马少鹏, 周辉. 岩石破坏过程中试件表面应变场演化特征研究[J]. 岩石力学与工程学报,2008,27(8):1667 − 1673. [MA Shaopeng, ZHOU Hui. Surface strain field evolution of rock specimen during failure process[J]. Chinese Journal of Rock Mechanics and Engineering,2008,27(8):1667 − 1673. (in Chinese with English abstract) doi: 10.3321/j.issn:1000-6915.2008.08.017
[22] 朱维申, 陈卫忠, 申晋. 雁形裂纹扩展的模型试验及断裂力学机制研究[J]. 固体力学学报,1998,19(4):355 − 360. [ZHU Weishen, CHEN Weizhong, SHEN Jin. Simulation experiment and fracture mechanism study on propagation of echelon pattern cracks[J]. Acta Mechanica Solida Sinica,1998,19(4):355 − 360. (in Chinese with English abstract)
[23] 张艳博, 杨震, 姚旭龙, 等. 基于红外辐射时空演化的巷道岩爆实时预警方法实验研究[J]. 采矿与安全工程学报,2018,35(2):299 − 307. [ZHANG Yanbo, YANG Zhen, YAO Xulong, et al. Experimental study on real-time early warning method of tunnel rock based on infrared radiation spatial and temporal evolutions[J]. Journal of Mining & Safety Engineering,2018,35(2):299 − 307. (in Chinese with English abstract)
-
下载:
图(9)
计量
- 文章访问数: 1850
- PDF下载数: 99
- 施引文献: 0