玄武岩节理系数及其与强度和变形特性的关系研究

Joint factor of basalt and its relationship with strength and deformation characteristics

节理密度、节理倾角与节理粗糙度情况等是控制玄武岩力学响应的三个关键因素。基于3D打印技术,通过开展单轴压缩与界面剪切试验,针对不同的模拟柱状节理玄武岩试样的破坏模式深入探究了特殊柱状节理的存在对玄武岩强度与变形的弱化作用,分析了节理系数与试样各向异性效应的关系。研究结果表明随节理系数的增大,模拟柱状节理玄武岩试样强度折减系数的线性减小程度及模量折减系数以指数关系式降低幅度受失效模式影响显著;强度各向异性效应与模量各向异性效应数值越大,表明柱状节理对玄武岩的岩块弱化作用越强;不同失效模式工况下,随节理系数的增加,强度各向异性效应线性增大,模量各向异性效应以指数关系式升高。研究成果可为工程岩体各向异性力学响应分析提供一定的技术支撑。

The joint density,joint inclination angle and joint roughness are the three key factors that control the mechanical response of basalts.Based on the 3D printing technology,the uniaxial compression and interfacial shear tests are carried out to deeply explore the weakening effects of the existence of special columnar joints on the strength and deformation of the basalts according to the failure modes of different columnar jointed basalt samples,and the relationship between the joint factor and the anisotropy effects of samples is analyzed.The research results show that with the increase of the joint factor,the linear reduction degree of the strength reduction coefficient and the exponential relation reduction degree of the modulus reduction coefficient of the simulated columnar jointed basalt samples are significantly affected by the failure mode.The larger the values of the strength anisotropy effects and modulus anisotropy effects,the stronger the weakening effects of columnar joints on basalt blocks.Under different failure modes,the strength anisotropy effects increases linearly with the increase of the joint factor,and the modulus anisotropy effects increase exponentially.The research results can provide some technical support for the anisotropic mechanical response analysis of engineering rock masses.