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裂隙岩体是工程最普遍的施工对象之一,工程扰动下裂隙的萌生、扩展和贯通均对岩体变形及强度特性产生显著影响。利用RMT–150C试验机及侧向加压设备,对含不同形式预制裂隙类岩石试样开展单轴及双轴压缩试验。结合不同加载条件下岩体裂隙扩展路径、破坏模式及声发射能量特征分析,并根据声发射定位事件特征,研究岩体裂隙网络在复杂应力条件下的扩展机制。分析结果表明:(1)侧向压力作用下,应力–应变曲线延性逐渐增强;(2)新生裂隙均自初始裂隙尖端产生并扩展,且侧压使得裂隙扩展路径会发生明显偏转;(3)声发射事件空间定位与宏观裂隙扩展过程具有较好的对应关系;(4)典型试样裂隙扩展前声发射定位事件占总定位事件比值均在80%以上,表明宏观裂隙扩展源自微裂隙的损伤累积。研究成果对于更加真实地分析模拟工程岩体失稳过程具有重要指导意义。
The fractured rock mass is one of the most common construction objects. The initiation, propagation and penetration of the fractures under the engineering disturbance all have a significant effect on the deformation and strength characteristics of the rock mass. Uniaxial and biaxial compression tests were carried out on rock samples containing different types of prefabricated fractures using RMT-150C testing machine and lateral pressure equipment. According to the propagation characteristics of rock crack propagation path, failure mode and acoustic emission energy under different loading conditions, the expansion mechanism of rock fracture network under complex stress conditions is studied according to the characteristics of acoustic emission positioning events. The results show that: (1) the ductility of the stress-strain curve gradually increases under the lateral pressure; (2) the nascent fissures are generated and propagated from the initial fissure tip and the lateral pressure causes the fissure propagation path to deflect significantly; (3) (4) The acoustic emission location events of typical samples before crack propagation are all above 80%, which shows that the macroscopic fracture propagation originates from the micro-fracture Damage accumulation. The research results have important guiding significance for more realistic analysis and simulation of rock instability process.