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利用MTS815 Flex GT岩石力学试验系统,对雪峰山隧道围岩中的砂板岩开展单轴和三轴试验,研究这种砂板岩中的细微层理对岩石变形特性、强度特性及其参数的影响,结果表明:岩石力学特性的各向异性特征显著。层理面与轴向力夹角0°时应力-应变曲线呈不稳定破裂特征,破坏面沿层理面方向发育;夹角90°时曲线呈峰后迅速软化特征,破坏面为对角贯通性剪切破坏。单轴试验中夹角0°的抗压强度比夹角90°高出约20%,弹性模量和变形模量比夹角90°分别约大50%和80%。三轴试验中2种夹角情况破坏时主应力差(σ1?σ3)max相近,夹角0°的弹性模量和变形模量分别比夹角90°时约大6%和20%,围压对砂板岩的各向异性特征有弱化效应。这些结论揭示了该砂板岩各向异性的力学特性,对解决工程实际问题有重要的参考价值。
Using MTS815 Flex GT rock mechanics test system, the uniaxial and triaxial tests of the sandstone in the surrounding rock of the Xuefengshan tunnel were carried out. The effects of fine bedding in this sandstone on deformation characteristics, strength characteristics and parameters of the rock The results show that the anisotropy of rock mechanics characteristics is remarkable. The stress-strain curve shows instable rupture when the included angle between layer plane and axial force is 0 °, and the failure surface develops along the direction of layer bedding plane. When the included angle is 90 °, the curve is rapidly softened after the peak, and the failure surface is diagonal through Sexual shear damage. In the uniaxial test, the compressive strength of 0 ° is about 20% higher than the included angle of 90 °, and the modulus of elasticity and the modulus of deformation are about 50% and 80% larger than the included angle of 90 °, respectively. In the triaxial test, the difference of the principal stress (σ1? Σ3) max is similar when the two kinds of angle conditions are destroyed, and the elastic modulus and the modulus of deformation at the included angle of 0 ° are about 6% and 20% larger than those at the included angle of 90 ° The anisotropic characteristics of sandstone have a weakening effect. These conclusions reveal the anisotropy of sandstone mechanical properties, to solve practical engineering problems have important reference value.