采用数字图像相关方法(digital image correlation,DIC)对含不同填充裂隙大理岩单轴压缩破坏过程进行观测,通过分析破裂过程大理岩表面全局变形场的演化,结合电镜扫描(scanning electron microscope,SEM)技术,从定性和定量的角度,总结...采用数字图像相关方法(digital image correlation,DIC)对含不同填充裂隙大理岩单轴压缩破坏过程进行观测,通过分析破裂过程大理岩表面全局变形场的演化,结合电镜扫描(scanning electron microscope,SEM)技术,从定性和定量的角度,总结不同裂隙倾角和不同裂隙填充条件下裂纹起裂、扩展及贯通的规律。结果表明:预制裂隙倾角的变化,会对裂纹的起裂点、起裂角和岩石的强度产生不同程度的影响;而填充物的存在使得岩石的抗压强度有一定程度的提高;无论裂隙填充与否,裂隙大理岩的破坏大都为剪切和张拉共同作用的结果;由于填充物的影响,岩石在宏观上表现为翼裂纹主导的破坏形式,在细观上表现为明显的剪切破坏趋势;但当裂隙中无填充时,大理岩在宏观上则有翼裂纹和反翼裂纹这2种主导破坏形式,在细观上表现为较明显的张拉破坏趋势。因此,采用DIC方法定量描述岩石破裂过程的裂纹位移场演化,直观的判断含填充和未填充裂隙岩石断裂类型,突破了传统以经验为主判断岩石断裂类型存在的局限性,该研究有助于提升人们对含填充裂隙岩体破坏机制的认识。展开更多
In the present work,uniaxial compressive tests were carried out on limestone-like samples containing two parallel open fissures or cement-infilled fissures with different geometries.Mechanical property and crack behav...In the present work,uniaxial compressive tests were carried out on limestone-like samples containing two parallel open fissures or cement-infilled fissures with different geometries.Mechanical property and crack behavior of limestone-like samples with two parallel open fissures or cement-infilled fissures were affected by bridge inclination angle and fissure inclination angle.Four types of coalescence of rock bridge for samples containing open fissures or cement-infilled fissures were summarized and classified.The closure of tensile crack was observed in the samples with small fissure inclination angle.This is a new phenomenon which is not mentioned in previous studies.Test results show that the peak strength,crack initiation stress,and coalescence type are different between open fissures and cement infilled fissures.The reason for this phenomenon is that grouting of cement can transfer stress and reduce stress concentration at the flaw tip and rock bridge area.展开更多
文摘采用数字图像相关方法(digital image correlation,DIC)对含不同填充裂隙大理岩单轴压缩破坏过程进行观测,通过分析破裂过程大理岩表面全局变形场的演化,结合电镜扫描(scanning electron microscope,SEM)技术,从定性和定量的角度,总结不同裂隙倾角和不同裂隙填充条件下裂纹起裂、扩展及贯通的规律。结果表明:预制裂隙倾角的变化,会对裂纹的起裂点、起裂角和岩石的强度产生不同程度的影响;而填充物的存在使得岩石的抗压强度有一定程度的提高;无论裂隙填充与否,裂隙大理岩的破坏大都为剪切和张拉共同作用的结果;由于填充物的影响,岩石在宏观上表现为翼裂纹主导的破坏形式,在细观上表现为明显的剪切破坏趋势;但当裂隙中无填充时,大理岩在宏观上则有翼裂纹和反翼裂纹这2种主导破坏形式,在细观上表现为较明显的张拉破坏趋势。因此,采用DIC方法定量描述岩石破裂过程的裂纹位移场演化,直观的判断含填充和未填充裂隙岩石断裂类型,突破了传统以经验为主判断岩石断裂类型存在的局限性,该研究有助于提升人们对含填充裂隙岩体破坏机制的认识。
基金Projects(42007256, 41672258) supported by the National Natural Science Foundation of ChinaProject(B210201002)supported by the Fundamental Research Funds for the Central Universities,China。
文摘In the present work,uniaxial compressive tests were carried out on limestone-like samples containing two parallel open fissures or cement-infilled fissures with different geometries.Mechanical property and crack behavior of limestone-like samples with two parallel open fissures or cement-infilled fissures were affected by bridge inclination angle and fissure inclination angle.Four types of coalescence of rock bridge for samples containing open fissures or cement-infilled fissures were summarized and classified.The closure of tensile crack was observed in the samples with small fissure inclination angle.This is a new phenomenon which is not mentioned in previous studies.Test results show that the peak strength,crack initiation stress,and coalescence type are different between open fissures and cement infilled fissures.The reason for this phenomenon is that grouting of cement can transfer stress and reduce stress concentration at the flaw tip and rock bridge area.
