压剪作用下节理倾角对类岩石材料破坏模式的影响

Influence of joint inclination angle on failure style of rock-like material with compressive-shear

采用在水泥砂浆初凝前预埋云母片的方法制作含不同分布形态的充填节理试件,并对试件进行压剪试验,探究压剪复合作用下节理倾角对岩体破坏模式的影响及节理岩体破坏机理。应用RFPA2D有限元程序建立相应的数值模型,进行数值计算。试验和数值模拟结果表明:节理倾角对试件初始破坏时翼裂纹的产生位置和最终破坏形态都有显著影响;不同倾角的节理在不同程度上弱化了类岩石试件的抗剪强度,节理倾角为15°时抗剪强度最小,而60°时最大;节理倾角小于45°时,试件破坏所需剪切位移小于无节理试件破坏时的剪切位移,节理倾角大于或等于45°时大于无节理试件破坏时的剪切位移。

To study the failure mechanism and failure mode of joint rock with compressive-shear, a series of experiments were carried out. In the experiments, the way of burying mica sheets in the cement mortar before initial setting was used to make specimens contain filled joints. The compressive-shear tests at 45° were conducted and RFPA2D was adopted to simulate the physical experiments. The results of experiments and numerical simulation show that the dip of joint plays a key role in the position of emerging wing cracks which first exist in the specimens’ breakage and markedly influence the finial failure modes. Joints of different inclination angles weaken shear strength of the specimens. The specimen with a joint inclination angle of 15° has the smallest shear strength, while the biggest value happens at 60°. When the shear stress reaches the peak value, the shear displacement in the specimens of a inclination angles ranging from 0° to 30° is less than those of intact specimens, and whilst the angle equals 45° or more, the shear displacement is much higher than those of intact specimens.