含交叉裂隙类岩石试样物理力学特性试验及其RFPA模拟

为探究含交叉裂隙试样在单轴应力下的物理力学特性,制备了与岩石力学性质相似的类岩石材料,利用预制树脂片法模拟了不同倾角交叉裂隙的情况,对其进行了单轴压缩试验,同时利用RFPA软件对不同工况进行了数值模拟。结果表明,含交叉裂隙类岩石试样在单轴应力下主要有单一裂隙扩展模式、主裂纹扩展贯通模式、次生裂纹扩展贯通模式三种破坏模式;单一裂隙扩展模式与主裂纹扩展模式下,次生裂隙尖端产生剪破坏,主裂纹尖端产生拉破坏,而次生裂纹扩展模式下主裂纹尖端产生剪破坏,次生裂纹尖端产生拉破坏,最终产生的翼裂纹与反翼裂纹属于拉剪破坏;单轴应力下的含交叉裂隙试样应力—应变曲线经历弹性变形阶段、非线性变形阶段、残余变形阶段三个阶段;主裂纹倾角对含交叉裂隙试样的峰值强度起到控制性作用,而次生裂隙仅在主裂纹倾角为0°时对试样的峰值强度有较大影响。

Test and RFPA Simulation of Physical and Mechanical Properties of Rock Specimen with Cross-fracture

In order to investigate the physical and mechanical properties of specimens containing cross-fracture under uniaxial stress, rock-like materials similar to those of rock mechanics were prepared, and the cross-cracks with different inclination angles were simulated by means of prefabricated resin sheet method. Uniaxial compression tests were carried out and numerical simulations were carried out under different working conditions by using RFPA software. The results show that there are mainly three failure modes for rock samples with cross cracks under uniaxial stress: single fracture propagation mode, main crack propagation mode, and secondary crack propagation mode; Under the single crack propagation mode and the main crack propagation mode, the secondary fracture tip produces shear failure, and the main crack tip leads to shear failure. Tensile failure occurs at the end, and shear failure occurs at the main crack tip and tensile failure at the secondary crack tip under the secondary crack propagation mode. Finally, the wing crack and the anti-wing crack are tensile and shear failure. The stress-strain curve of specimen with cross-fracture under uniaxial stress goes through three stages: elastic deformation stage, nonlinear deformation stage, and residual deformation stage; The inclination angle of the main crack plays a controlling role on the peak strength of the specimen with cross fracture, while the secondary crack has a great impact on the peak strength of the specimen only when the inclination angle of the main crack is 0 degrees.