论文部分内容阅读
岩石内天然存在长度、倾角和形态不同的裂隙,造成岩石的各向异性特征。为揭示岩石内天然随机裂隙发育特征对岩石物理力学特性的影响规律,以泥巴山隧址区采集裂隙性流纹岩为研究对象,首先对试样裂隙进行素描统计分析;然后基于Oda裂隙结构张量,获得天然随机分布裂隙的几何统计参数;最后对裂隙性流纹岩试样分别进行单轴和常规三轴压缩试验,得到不同应力路径下流纹岩的应力-应变曲线及物理力学参数。分析Oda裂隙结构张量定义的各向异性参数与试验获得的力学参数之间的规律,研究结果表明:(1)Oda裂隙结构张量适用于天然随机分布裂隙的几何统计分析,各向异性参数A(F)越大,裂隙优势方向越明显;(2)单轴压缩下,随着各向异性参数I1和A(F)的增大,流纹岩各向异性程度增大,弹性模量减小,泊松比增大;(3)常规三轴压缩下,流纹岩弹性模量和泊松比随各向异性参数改变的规律较不明显,Oda裂隙结构张量不再适用。
Rocks naturally exist in the length, inclination and shape of the cracks, causing the anisotropy of rock characteristics. In order to reveal the regularity of the influence of natural random fractures in the rock on the physical and mechanical properties of rock, taking the fissured rhyolite collected from the tunnel site of the Nabashan Mountain as the research object, the fractures of the samples were first analyzed by the sketch statistical analysis. Then, The geometrical statistical parameters of the randomly distributed fractures were obtained. Finally, the uniaxial and conventional triaxial compression tests of the fractured rhyolite samples were carried out respectively, and the stress-strain curves and physico-mechanical parameters of rhyolite under different stress paths were obtained. The results show that: (1) The tensor of Oda crack structure is suitable for the geometrical statistical analysis of randomly distributed natural fractures. The anisotropy parameter (2) Under the uniaxial compression, the anisotropy of rhyolite increases with the increase of anisotropy parameters I1 and A (F), the elastic modulus (3) Under conventional triaxial compression, the law of elastic modulus and Poisson’s ratio changing with anisotropy parameters is less obvious, and the tensor of Oda fracture structure is no longer applicable.