含横向节理的柱状节理岩体力学特性试验研究

针对柱状节理岩体的构造特性，采用水泥砂浆等材料制作出具有不同柱体倾角且含有横向节理分布的柱状节理岩体模型，并通过单轴压缩试验，研究柱体倾角和横向节理对岩体各向异性力学特性及破坏机制的影响。结果表明：试样峰值强度和变形模量随柱体倾角变化曲线均近似为U形，并体现出典型的各向异性特征；随着柱体倾角的变化，试样单轴压缩破坏模式可分为垂直于柱体轴向的劈裂破坏、沿纵向节理面的剪切滑移破坏、滑移破坏与劈裂破坏同时发生的复合破坏和平行于柱体轴向的劈裂破坏4类；横向节理的存在降低了柱状节理岩体沿柱轴方向的完整性，并影响了劈裂破坏裂纹的分布与扩展，因此，横向节理切割柱体是影响柱状节理岩体承载能力的重要因素。

Experimental study of mechanical behaviour of artificial columnar jointed rock mass containing transverse joints

Based on the geological structure of columnar jointed rock mass, artificial columnar jointed rock mass specimens with different column dip angles and transverse joints were made of cement mortar. Uniaxial compression tests were carried out to investigate the effect of dip angles and transverse joints on mechanical behaviour and failure modes. The results showed that the shape of various curves of deformation modulus and peak strength with dip angles were similar to the letter “U” which indicated significant anisotropy. With the dip angles changed, the failure modes of columnar jointed rock mass under uniaxial compression would be different. Four typical failure modes were summarised, i.e., the splitting failure orthogonal to column axis, shear-sliding failure, comprehensive failure of splitting and shear-sliding, splitting failure along the column axis. Since the transverse joints cut off columns, the integrity of rock mass was reduced along the axial direction, which influenced the distribution and coalescence of splitting fracture. Thus, the bearing capacity of columnar jointed rock mass was largely affected by the transverse joints.