含预制椭圆形孔洞大理岩变形破坏力学特性试验研究
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摘要
通过对含预制椭圆形孔洞板状大理岩试样进行单轴压缩试验,研究椭圆长短轴比m及倾角?对大理岩力学特性的影响,并借助数字图像相关技术(DIC)记录并分析试样的变形破裂过程。研究发现,含椭圆形孔洞试样的峰值强度、弹性模量和起裂应力水平都随倾角的增大而增大,且对倾角和长短轴比的变化都有不同的敏感性,其中峰值强度对倾角变化的敏感程度随长短轴比的增大而增大。含椭圆形孔洞试样的最终破坏模式随倾角的增大可分为拉–剪混合破坏和剪切破坏2种,而孔洞长短轴比的变化对裂纹搭接及岩样破坏形态的影响较小。含椭圆形孔洞岩样在峰值前后的变形破裂特征能够通过观测试样表面应变场得到清晰地表征,其中局部高应变区预示着裂纹的起裂和扩展。基于局部化特征,提出一种含孔洞缺陷岩石起裂应力的测量方法,当含椭圆形孔洞试样起裂应力水平达到39.83%～76.18%时,试样处于拉伸裂纹临界起裂状态。
By conducting uniaxial compression tests on prismatic marble specimens containing prefabricated elliptical holes,the effects of major-minor axis ratio(m) and inclination angle(?) of ellipse on the mechanical characteristics of rock were studied. Digital image correlation(DIC) was also applied to record and analyze the fracturing process and damage evolution of marble. The results show that the peak strength,elastic modulus and crack initiation stress level of specimens containing elliptical holes increase with the increase of ?,and all have different sensitivity to ? and m,in which the sensitivity of the peak strength to ? increases with the increase of m.With the increase of ?,the final failure modes of specimens containing elliptical holes can be mainly classified into splitting-shearing failure and shearing failure,while the influence of m on the crack coalescence and rock failure mode is not obvious. By observing the strain field on specimen surface,it is found that the deformation and fracture characteristics of marble before and after peak stress can be clearly characterized,where the local high strain zones are good indications of crack initiation and propagation. Based on the localization characteristics of global strain field,a method for measuring the crack initiation stress of rock with hole defects is proposed. When the crack initiation stress level reaches 39.83%–76.18%,the specimens containing elliptical holes are in the critical tensile crack initiation state.
By conducting uniaxial compression tests on prismatic marble specimens containing prefabricated elliptical holes,the effects of major-minor axis ratio(m) and inclination angle(?) of ellipse on the mechanical characteristics of rock were studied. Digital image correlation(DIC) was also applied to record and analyze the fracturing process and damage evolution of marble. The results show that the peak strength,elastic modulus and crack initiation stress level of specimens containing elliptical holes increase with the increase of ?,and all have different sensitivity to ? and m,in which the sensitivity of the peak strength to ? increases with the increase of m.With the increase of ?,the final failure modes of specimens containing elliptical holes can be mainly classified into splitting-shearing failure and shearing failure,while the influence of m on the crack coalescence and rock failure mode is not obvious. By observing the strain field on specimen surface,it is found that the deformation and fracture characteristics of marble before and after peak stress can be clearly characterized,where the local high strain zones are good indications of crack initiation and propagation. Based on the localization characteristics of global strain field,a method for measuring the crack initiation stress of rock with hole defects is proposed. When the crack initiation stress level reaches 39.83%–76.18%,the specimens containing elliptical holes are in the critical tensile crack initiation state.
引文
[1]刘晓丽,王思敬,王恩志,等.单轴压缩岩石中缺陷的演化规律及岩石强度[J].岩石力学与工程学报,2008,27(6):1 195-1 201.(LIU Xiaoli,WANG Sijing,WANG Enzhi,et al.Evolutionary rules of flaws in rock subjected to uniaxial compression and rock strength[J].Chinese Journal of Rock Mechanics and Engineering,2008,27(6):1 195-1 201.(in Chinese))
[2]靖洪文,苏海健,杨大林,等.损伤岩样强度衰减规律及其尺寸效应研究[J].岩石力学与工程学报,2012,31(3):543-549.(JINGHongwen,SU Haijian,YANG Dalin,et al.Study of strength degradation law of damaged rock sample and its size effect[J].Chinese Journal of Rock Mechanics and Engineering,2012,31(3):543-549.(in Chinese))
[3]YANG S Q,JING H W,XU T.Mechanical behavior and failure analysis of brittle sandstone specimens containing combined flaws under uniaxial compression[J].Journal of Central South University,2014,21(5):2 059-2 073.
[4]赵程,田加深,松田浩,等.单轴压缩下基于全局应变场分析的岩石裂纹扩展及其损伤演化特性研究[J].岩石力学与工程学报,2015,34(4):763-769.(ZHAO Cheng,TIAN Jiashen,MATSUDA Hiroshi,et al.Crack propagation and damage of rock under uniaxial compression based on global strain field analysis[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(4):763-769.(in Chinese))
[5]BOBET A.Modelling of crack initiation,propagation and coalescence in uniaxial compression[J].Rock Mechanics and Rock Engineering,2000,33(2):119-139.
[6]SAMMIS C G,ASHBY M F.The failure of brittle porous solids under compressive stress states[J].Acta Metallurgica,1986,34(3):511-526.
[7]HORII H,NEMAT-NASSER S.Compression-induced microcrack growth in brittle solids:axial splitting and shear failure[J].Journal of Geophysical Research Solid Earth,1985,90(B4):3 105-3 125.
[8]LAJTAI E Z,LAJTAI V N.The collapse of cavities[J].International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts,1975,12(4):81-86.
[9]CARTER B J,LAJTAI E Z,PETUKHOV A.Primary and remote fracture around underground cavities[J].International Journal for Numerical and Analytical Methods in Geomechanics,2010,15(1):21-40.
[10]KOBAYASHI A S,JOHNSON B,WADE B G.Crack approaching a hole[C]//Proceedings of 1973 Nat?l.Symp.[S.l.]:ASTMSTP,1974:53-68.
[11]WONG R H C,LIN P,TANG C A.Experimental and numerical study on splitting failure of brittle solids containing single pore under uniaxial compression[J].Mechanics of Materials,2006,38(1/2):142-159.
[12]李地元,成腾蛟,周韬,等.冲击载荷作用下含孔洞大理岩动态力学破坏特性试验研究[J].岩石力学与工程学报,2015,34(2):249-260.(LI Diyuan,CHENG Tengjiao,ZHOU Tao,et al.Experimental study of the dynamic strength and fracturing characteristics of marble specimens with a single hole under impact loading[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(2):249-260.(in Chinese))
[13]杨圣奇,刘相如,李玉寿.单轴压缩下含孔洞裂隙砂岩力学特性试验分析[J].岩石力学与工程学报,2012,31(增2):3 539-3 546.(YANG Shengqi,LIU Xiangru,LI Yushou.Experimental analysis of mechanical behavior of sandstone containing hole and fissure under uniaxial compression[J].Chinese Journal of Rock Mechanics and Engineering,2012,31(Supp.2):3 539-3 546.(in Chinese))
[14]杨圣奇,吕朝辉,渠涛.含单个孔洞大理岩裂纹扩展细观试验和模拟[J].中国矿业大学学报,2009,38(6):774-781.(YANGShengqi,LU Chaohui,QU Tao.Investigations of crack expansion in marble having a single pre-existing hole:experiment and simulations[J].Journal of China University of Mining and Technology,2009,38(6):774-781.(in Chinese))
[15]刘招伟,李元海.含孔洞岩石单轴压缩下变形破裂规律的试验研究[J].工程力学,2010,27(8):133-139.(LIU Zhaowei,LI Yuanhai.Experimental investigation on the deformation and crack behavior of rock specimen with a hole undergoing uniaxial compression load[J].Engineering Mechanics,2010,27(8):133-139.(in Chinese))
[16]宋义敏,马少鹏,杨小彬,等.岩石变形破坏的数字散斑相关方法研究[J].岩石力学与工程学报,2011,30(1):170-175.(SONGYimin,MA Shaopeng,YANG Xiaobin,et al.Experimental investigation on failure of rock by digital speckle correlation methods[J].Chinese Journal of Rock Mechanics Engineering,2011,30(1):170-175.(in Chinese))
[17]纪维伟,潘鹏志,苗书婷,等.基于数字图像相关法的两类岩石断裂特征研究[J].岩土力学,2016,37(8):2 299-2 305.(JIWeiwei,PAN Pengzhi,MIAO Shuting,et al.Fracture characteristics of two types of rocks based on digital image correlation[J].Rock and Soil Mechanics,2016,37(8):2 299-2 305.(in Chinese))
[18]赵程,鲍冲,松田浩,等.数字图像技术在节理岩体裂纹扩展试验中的应用研究[J].岩土工程学报,2015,37(5):944-951.(ZHAO Cheng,BAO Chong,MATSUDA Hiroshi,et al.Application of digital correlation method in experimental research on crack propagation of brittle rock[J].Chinese Journal of Geotechnical Engineering,2015,37(5):944-951.(in Chinese))
[19]赵程,鲍冲,田加深,等.基于应变局部化的双裂纹岩样贯通模式及强度试验研究[J].岩石力学与工程学报,2015,34(11):2 309-2 318.(ZHAO Cheng,BAO Chong,TIAN Jiashen,et al.Experimental study of coalescence mode of cracks and strength of rock with double flaws based on strain Localization[J].Chinese Journal of Rock Mechanics Engineering,2015,34(11):2 309-2 318.(in Chinese))
[20]ZHANG H,FU D H,SONG H P,et al.Damage and fracture investigation of three-point bending notched sandstone beams by DICand AE techniques[J].Rock Mechanics and Rock Engineering,2015,48(3):1 297-1 303.
[21]杜明瑞,靖洪文,苏海健,等.含预制椭圆形孔洞砂岩强度及破坏特征试验研究[J].中国矿业大学学报,2016,45(6):1 164-1 171.(DU Mingrui,JING Hongwen,SU Haijian,et al.Experimental study of strength and failure characteristics of sandstone containing prefabricated elliptical hole[J].Journal of China University of Mining and Technology,2016,45(6):1 164-1 171.(in Chinese))
[22]杜明瑞,靖洪文,苏海健.椭圆形孔洞对砂岩试样强度及变形特征影响研究[J].采矿与安全工程学报,2017,34(1):141-147.(DUMingrui,JING Hongwen,SU Haijian.Study on the influence of elliptical hole on strength and deformation characteristics of sandstone sample[J].Journal of of Mining and Safety Engineering,2017,34(1):141-147.(in Chinese))
[23]陈新,彭曦,李东威,等.基于两种破裂判据的裂隙岩体单轴压缩起裂分析[J].工程力学,2013,30(10):227-235.(CHENXin,PENG Xi,LI Dongwei,et al.Analysis on cracking mechanism of fractured rock masses under uniaxial compression based on the two cracking criteria[J].Engineering Mechanics,2013,30(10):227-235.(in Chinese))
[24]LI X B,ZHOU T,LI D Y,et al.Experimental and numerical investigations on feasibility and validity of prismatic rock specimen in SHPB[J].Shock and Vibration,2016,(2):1-13.
[25]NOLEN-HOEKSEMA R C,GORDON R B.Optical detection of crack patterns in the opening-mode fracture of marble[J].International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts,1987,24(2):135-144.
[26]BROWN E T.Rock characterization,testing and monitoring:ISRMsuggested methods[M].London:Pergamon Press,1981:171-183.
[27]章超.数字图像相关方法在动态测试中的应用[硕士学位论文][D].合肥:中国科学技术大学,2014.(ZHANG Chao.Application of digital imaging correlation in dynamic testing[M.S.Thesis][D].Hefei:University of Science and Technology of China,2014.(in Chinese))
[28]LI D Y,ZHU Q Q,ZHOU Z L,et al.Fracture analysis of marble specimens with a hole under uniaxial compression by digital image correlation[J].Engineering Fracture Mechanics,2017,183:109-124.
[29]MARTIN C D.The strength of massive Lac du bonnet granite around underground openings[Ph.D.Thesis][D].Winnipeg,Manitoba:University of Manitoba,1993.
[30]YANG S Q.Crack coalescence behavior of brittle sandstone samples containing two coplanar fissures in the process of deformation failure[J].Engineering Fracture Mechanics,2011,78(17):3 059-3 081.
[31]王宇,李晓,武艳芳,等.脆性岩石起裂应力水平与脆性指标关系探讨[J].岩石力学与工程学报,2014,33(2):264-275.(WANG Yu,LI Xiao,WU Yanfang,et al.Research on relationship between crack initiation stress level and brittleness indices for brittle rocks[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(2):264-275.(in Chinese))
[2]靖洪文,苏海健,杨大林,等.损伤岩样强度衰减规律及其尺寸效应研究[J].岩石力学与工程学报,2012,31(3):543-549.(JINGHongwen,SU Haijian,YANG Dalin,et al.Study of strength degradation law of damaged rock sample and its size effect[J].Chinese Journal of Rock Mechanics and Engineering,2012,31(3):543-549.(in Chinese))
[3]YANG S Q,JING H W,XU T.Mechanical behavior and failure analysis of brittle sandstone specimens containing combined flaws under uniaxial compression[J].Journal of Central South University,2014,21(5):2 059-2 073.
[4]赵程,田加深,松田浩,等.单轴压缩下基于全局应变场分析的岩石裂纹扩展及其损伤演化特性研究[J].岩石力学与工程学报,2015,34(4):763-769.(ZHAO Cheng,TIAN Jiashen,MATSUDA Hiroshi,et al.Crack propagation and damage of rock under uniaxial compression based on global strain field analysis[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(4):763-769.(in Chinese))
[5]BOBET A.Modelling of crack initiation,propagation and coalescence in uniaxial compression[J].Rock Mechanics and Rock Engineering,2000,33(2):119-139.
[6]SAMMIS C G,ASHBY M F.The failure of brittle porous solids under compressive stress states[J].Acta Metallurgica,1986,34(3):511-526.
[7]HORII H,NEMAT-NASSER S.Compression-induced microcrack growth in brittle solids:axial splitting and shear failure[J].Journal of Geophysical Research Solid Earth,1985,90(B4):3 105-3 125.
[8]LAJTAI E Z,LAJTAI V N.The collapse of cavities[J].International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts,1975,12(4):81-86.
[9]CARTER B J,LAJTAI E Z,PETUKHOV A.Primary and remote fracture around underground cavities[J].International Journal for Numerical and Analytical Methods in Geomechanics,2010,15(1):21-40.
[10]KOBAYASHI A S,JOHNSON B,WADE B G.Crack approaching a hole[C]//Proceedings of 1973 Nat?l.Symp.[S.l.]:ASTMSTP,1974:53-68.
[11]WONG R H C,LIN P,TANG C A.Experimental and numerical study on splitting failure of brittle solids containing single pore under uniaxial compression[J].Mechanics of Materials,2006,38(1/2):142-159.
[12]李地元,成腾蛟,周韬,等.冲击载荷作用下含孔洞大理岩动态力学破坏特性试验研究[J].岩石力学与工程学报,2015,34(2):249-260.(LI Diyuan,CHENG Tengjiao,ZHOU Tao,et al.Experimental study of the dynamic strength and fracturing characteristics of marble specimens with a single hole under impact loading[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(2):249-260.(in Chinese))
[13]杨圣奇,刘相如,李玉寿.单轴压缩下含孔洞裂隙砂岩力学特性试验分析[J].岩石力学与工程学报,2012,31(增2):3 539-3 546.(YANG Shengqi,LIU Xiangru,LI Yushou.Experimental analysis of mechanical behavior of sandstone containing hole and fissure under uniaxial compression[J].Chinese Journal of Rock Mechanics and Engineering,2012,31(Supp.2):3 539-3 546.(in Chinese))
[14]杨圣奇,吕朝辉,渠涛.含单个孔洞大理岩裂纹扩展细观试验和模拟[J].中国矿业大学学报,2009,38(6):774-781.(YANGShengqi,LU Chaohui,QU Tao.Investigations of crack expansion in marble having a single pre-existing hole:experiment and simulations[J].Journal of China University of Mining and Technology,2009,38(6):774-781.(in Chinese))
[15]刘招伟,李元海.含孔洞岩石单轴压缩下变形破裂规律的试验研究[J].工程力学,2010,27(8):133-139.(LIU Zhaowei,LI Yuanhai.Experimental investigation on the deformation and crack behavior of rock specimen with a hole undergoing uniaxial compression load[J].Engineering Mechanics,2010,27(8):133-139.(in Chinese))
[16]宋义敏,马少鹏,杨小彬,等.岩石变形破坏的数字散斑相关方法研究[J].岩石力学与工程学报,2011,30(1):170-175.(SONGYimin,MA Shaopeng,YANG Xiaobin,et al.Experimental investigation on failure of rock by digital speckle correlation methods[J].Chinese Journal of Rock Mechanics Engineering,2011,30(1):170-175.(in Chinese))
[17]纪维伟,潘鹏志,苗书婷,等.基于数字图像相关法的两类岩石断裂特征研究[J].岩土力学,2016,37(8):2 299-2 305.(JIWeiwei,PAN Pengzhi,MIAO Shuting,et al.Fracture characteristics of two types of rocks based on digital image correlation[J].Rock and Soil Mechanics,2016,37(8):2 299-2 305.(in Chinese))
[18]赵程,鲍冲,松田浩,等.数字图像技术在节理岩体裂纹扩展试验中的应用研究[J].岩土工程学报,2015,37(5):944-951.(ZHAO Cheng,BAO Chong,MATSUDA Hiroshi,et al.Application of digital correlation method in experimental research on crack propagation of brittle rock[J].Chinese Journal of Geotechnical Engineering,2015,37(5):944-951.(in Chinese))
[19]赵程,鲍冲,田加深,等.基于应变局部化的双裂纹岩样贯通模式及强度试验研究[J].岩石力学与工程学报,2015,34(11):2 309-2 318.(ZHAO Cheng,BAO Chong,TIAN Jiashen,et al.Experimental study of coalescence mode of cracks and strength of rock with double flaws based on strain Localization[J].Chinese Journal of Rock Mechanics Engineering,2015,34(11):2 309-2 318.(in Chinese))
[20]ZHANG H,FU D H,SONG H P,et al.Damage and fracture investigation of three-point bending notched sandstone beams by DICand AE techniques[J].Rock Mechanics and Rock Engineering,2015,48(3):1 297-1 303.
[21]杜明瑞,靖洪文,苏海健,等.含预制椭圆形孔洞砂岩强度及破坏特征试验研究[J].中国矿业大学学报,2016,45(6):1 164-1 171.(DU Mingrui,JING Hongwen,SU Haijian,et al.Experimental study of strength and failure characteristics of sandstone containing prefabricated elliptical hole[J].Journal of China University of Mining and Technology,2016,45(6):1 164-1 171.(in Chinese))
[22]杜明瑞,靖洪文,苏海健.椭圆形孔洞对砂岩试样强度及变形特征影响研究[J].采矿与安全工程学报,2017,34(1):141-147.(DUMingrui,JING Hongwen,SU Haijian.Study on the influence of elliptical hole on strength and deformation characteristics of sandstone sample[J].Journal of of Mining and Safety Engineering,2017,34(1):141-147.(in Chinese))
[23]陈新,彭曦,李东威,等.基于两种破裂判据的裂隙岩体单轴压缩起裂分析[J].工程力学,2013,30(10):227-235.(CHENXin,PENG Xi,LI Dongwei,et al.Analysis on cracking mechanism of fractured rock masses under uniaxial compression based on the two cracking criteria[J].Engineering Mechanics,2013,30(10):227-235.(in Chinese))
[24]LI X B,ZHOU T,LI D Y,et al.Experimental and numerical investigations on feasibility and validity of prismatic rock specimen in SHPB[J].Shock and Vibration,2016,(2):1-13.
[25]NOLEN-HOEKSEMA R C,GORDON R B.Optical detection of crack patterns in the opening-mode fracture of marble[J].International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts,1987,24(2):135-144.
[26]BROWN E T.Rock characterization,testing and monitoring:ISRMsuggested methods[M].London:Pergamon Press,1981:171-183.
[27]章超.数字图像相关方法在动态测试中的应用[硕士学位论文][D].合肥:中国科学技术大学,2014.(ZHANG Chao.Application of digital imaging correlation in dynamic testing[M.S.Thesis][D].Hefei:University of Science and Technology of China,2014.(in Chinese))
[28]LI D Y,ZHU Q Q,ZHOU Z L,et al.Fracture analysis of marble specimens with a hole under uniaxial compression by digital image correlation[J].Engineering Fracture Mechanics,2017,183:109-124.
[29]MARTIN C D.The strength of massive Lac du bonnet granite around underground openings[Ph.D.Thesis][D].Winnipeg,Manitoba:University of Manitoba,1993.
[30]YANG S Q.Crack coalescence behavior of brittle sandstone samples containing two coplanar fissures in the process of deformation failure[J].Engineering Fracture Mechanics,2011,78(17):3 059-3 081.
[31]王宇,李晓,武艳芳,等.脆性岩石起裂应力水平与脆性指标关系探讨[J].岩石力学与工程学报,2014,33(2):264-275.(WANG Yu,LI Xiao,WU Yanfang,et al.Research on relationship between crack initiation stress level and brittleness indices for brittle rocks[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(2):264-275.(in Chinese))