基于3D打印技术的岩体结构面各向异性剪切力学行为

Anisotropic shear behavior of rock joint based on 3D printing technology

结构面形貌特征是影响结构面剪切行为的重要因素,而且结构面形貌特征的各向异性与其剪切力学行为的各向异性之间存在一定的联系。利用三维激光扫描和3D打印技术模拟了天然结构面,并以水泥砂浆为材料浇筑了尺寸为100 mm×100 mm×150 mm的含结构面试样,开展了不同法向应力下沿不同方向的剪切试验。结果表明,结构面的剪切行为具有明显的各向异性,这种特性可以体现在峰值剪切强度及相应的剪切位移和抗剪强度参数上;在低法向应力条件下,峰值剪切强度各向异性的强弱程度与法向应力之间并非呈现简单的单调变化关系;抗剪强度参数c(黏聚力)、Φ(内摩擦角)值沿不同剪切方向的变化趋势总体上较相似;通过分析不同剪切方向上c、Φ值相对于0°方向的差异程度,可以发现剪切方向对c值的影响更为强烈。

Topography is an important factor affecting the shear behavior of joint.Furthermore,there are certain connections between the anisotropy of topography and the anisotropy of shear behavior.In this study,3D laser scanning technology and 3D printing technology were used to make molds for simulating the topography of natural joint.Then,the cement mortar samples with dimension of 100 mm×100 mm×150 mm were cast,and shear tests with different shear directions under different normal stresses were conducted.The results indicate that obvious anisotropy has been shown in the joint shear behavior,which is reflected in the peak shear strength and the corresponding shear displacement and shear strength parameters,respectively.In addition,the anisotropy of the peak shear strength do not present simple monotone to the normal stress under low normal stress.The shear strength parameters c and?with different directions both show significant anisotropy,and the values of them have similar variation tendency.What’s more,the results also indicate that the shear direction has a stronger influence on the cohesion by analyzing the discrepancy of cohesion and internal friction angle compared to 0°.