EXPERIMENTS AND SIMULATIONS ON FRACTURE OF ROCK WITH DIFFERENT NUMBERS OF FISSURES
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摘要: 采用岩石力学伺服试验机,对含有预制裂纹的辉石似长岩进行单轴压缩试验,分析不同裂隙数目的岩石的裂纹启裂、扩展和贯通破坏规律,并利用扩展有限元软件XFEM模拟解释分析试验现象。研究结果表明:辉石似长岩的单轴抗压强度随着裂纹数量的增加而呈线性下降;随着裂纹数量的增加,裂纹尖端位置与远离裂纹位置应变比值增加;多裂纹岩石出现次生裂纹时,试件应力达到峰值之后有应力回弹现象;对单裂纹、双裂纹、三裂纹试件的萌生、扩展及贯通过程的模拟表明,与试验岩石翼裂纹萌生、扩展破坏过程相似度较高。Abstract: Uniaxial compression experiments were conducted for pyroxenite specimens with pre-slotted fissures by the rock mechanics servo-controlled testing system. The laws of initiation, propagation and coalescence of rock specimens with different numbers of fissures were studied. The experiment phenomena were expounded by XFEM simulations. The study showed that the uniaxial compressive strength of pyroxenite specimens decreased linearly with the increase of numbers of cracks; as numbers of pre-slotted fissures increased, the rates of the strain at the pre-slotted fissure tips to that away from the pre-slotted fissures increased. When there were secondary cracks in multiple pre-slotted fissure specimens, stress would rebound after reaching the peak. The process of initiation, propagation and coalescence of specimens with a single, double or three pre-slotted fissures were simulated. The laws of crack initiation, evolution and coalescence processes obtained by numerical simulations were similar to that by tests.
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Key words:
- compressive strength /
- crack propagation /
- crack coalescence /
- strain /
- XFEM
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