对含有不同倾角的预制裂隙类岩石试样进行单轴静载态压缩试验,研究裂隙倾角对于试样强度、破坏模式、破坏过程及裂纹起裂和扩展规律的影响。研究发现,含有预制裂隙的类岩石试样与完整试样的应力-应变曲线相似,可分为压密段、线弹性段、裂纹稳定扩展段、应变软化段和残余强度段。含裂隙岩石的峰值抗压强度随裂隙倾角的逐渐增大呈V 字形变化,裂隙倾角45°时,岩石的峰值抗压强度最低,裂隙倾角0°和90°时,岩石的峰值抗压强度最高。裂纹的起裂角随裂隙倾角的增加而逐渐减小,裂纹的起裂速度和稳定扩展速度随裂隙倾角的增大逐渐增大。裂纹随载荷的逐渐增加,从预制裂隙尖端开始起裂,在初始加载阶段,由于岩石还具有一定的强度,裂隙扩展不明显,达到一定的载荷时,裂隙迅速而稳定扩展,直至完全破坏。
The effect of crack inclination angle on strength, failure mode, failure process, law of crack initiation and propagation is studied by uniaxial compression test on rocklike specimens with single pre-existing cracks of different inclination angles. It has been found that the stress-strain curve of the cracked specimen goes through five stages: compressive densification stage, stable linear elastic stage, crack extension stage, strain softening stage and residual strength stage, which is similar to the intact sample. The peak compressive strength of the cracked sample changes as a V-shaped curve with the increase of the crack inclination angle, and the minimum peak compressive strength is at the angle of 45° and the maximum compressive strength at angle 0°or 90°. The crack initiation angle decreases gradually with the increase of the crack inclination angle; on the contrary, the initiation speed and stable propagation speed of the crack increase with the crack inclination angle. The crack starts to expand with the increasing load gradually. The crack extension is stable and not obvious at first, when the load reaches a certain value, the crack expands quickly until the cracked specimen is broken completely.
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