| 摘要: |
| 为了研究岩桥倾角α对岩石力学行为和裂纹扩展机制的影响，采用PFC3D程序中的颗粒平行黏结模型，通过试错法获得一组能够反映完整花岗岩宏观力学特性的细观参数，并建立不同α下微孔洞与平行裂隙①、②组合的数值模型，对三轴压缩中试样变形破坏过程进行了模拟分析。结果表明：α对起裂强度与峰值强度的比值没有显著的影响；当α=0°和75°时裂纹扩展模式相近，裂隙①、②内外尖端均产生翼型裂纹，随后与微孔洞贯通j；当α=15°、30°、90°时裂纹的扩展模式较相近，裂隙①、②内外尖端也可见翼型裂纹；当α=45°、60°时裂纹呈相近方式扩展，裂隙①、②与微孔洞之间在剪切面上出现裂纹贯通，且在裂隙①、②外尖端有剪切裂纹，此时平行裂隙和微孔洞在剪切面上；剪切裂纹远多于拉伸裂纹，且微裂纹是从初始损伤部位开始扩展的。上述研究成果对分析含初始损伤岩样的受载破坏机理有一定参考价值。 |
| 关键词: 花岗岩 初始缺陷 岩桥倾角 裂纹演化 数值模拟 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| Particle flow simulation of deformation and failure process of defective rock samples under triaxial compression |
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Wang Haoran, Wang Zhiliang, Wang Xingchen
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Hefei University of Technology
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| Abstract: |
| To study the influence of dip angle of rock bridge on rock mechanical behavior and crack propagation mechanism, the particle parallel bonding model in the PFC3D code was used to obtain a group of microscopic parameters, which could reflect the macroscopic mechanical properties of intact granite via trial and error method. A numerical model of the combination of micro-void and parallel fissures ① and ② under different rock bridge angles was established, and the deformation and failure process of the sample in the triaxial compression were analyzed. Results show there was no significant effect on the ratio of the initiation strength to the peak strength; when α = 0° and 75°, the crack propagation modes were similar, and wing cracks were initiated at the inner and outer tips of the fissure ① and ②, and then coalesced with the micro-void; when α=15°, 30°, and 90°, the crack propagation mode was relatively similar, the wing cracks could be observed at the tips of the fissures ① and ②; when α=45°, 60°, the cracks grew in a similar manner, there were crack coalescence on the shear plane between the fissures ① and ② and the micro-void, and there were shear cracks at the outer tips of the fissures ① and ②. In this case, both the parallel fissures and the micro-void were on the shear plane; the number of shear cracks was far more numerous than that of the tensile cracks, and the micro-cracks extended from the initial damage zone. The above research has a certain reference value for analyzing the failure mechanism of rock samples with initial flaws. |
| Key words: Granite initial flaw dip angle of rock bridge crack evolution numerical simulation |
