To reveal the influence of prefabricated fractures (PFs) with different parameters on the extension of grouting-induced splitting fractures, a combination of numerical simulation and physical experiments were used to carry out grouting trials on similar materials to coal rock. The RFPA software was used to simulate the whole process of fracture initiation and expansion of coal rock with PFs during grouting. In the experiment, acoustic emission (AE) technology was used to monitor the extension process of grouting-induced splitting fractures. The results demonstrated that when the PFs do not intersect with the grouting holes, the extension of grouting-induced splitting fractures in rocks containing PFs experienced four stages: splitting and penetrating, slurry filling, fracture splitting and splitting extension. PFs have an orienting effect on the direction of grouting fracture extension and the size of the PFs influenced the extension of the grouting-induced splitting fractures: the larger the size, the easier the surrounding rocks were ruptured, the easier the connection was formed of channels between the grouting-induced splitting fractures and the PFs were formed, and the more complex the secondary splitting pattern in the PFs. This indicated that the angle of PFs played a decisive role in determining the extension direction of grouting-induced splitting fractures. The extension of grouting-induced splitting fractures during grouting of rock mass with different parameters is revealed by numerical simulation and experimental results.

中文翻译：

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在类似于包含预制裂缝的煤岩的材料中扩展注浆引起的裂隙裂缝

为了揭示具有不同参数的预制裂缝（PFs）对注浆引起的裂隙扩展的影响，数值模拟和物理实验相结合被用于对与煤岩相似的材料进行注浆试验。RFPA软件用于模拟注浆过程中含PF的煤岩裂缝萌生和膨胀的全过程。在实验中，声发射（AE）技术用于监测灌浆引起的裂隙裂缝的扩展过程。结果表明，当PFs不与注浆孔相交时，含PFs的岩石中由灌浆引起的裂隙裂缝的扩展经历了四个阶段：裂隙和渗透，泥浆充填，裂缝裂隙和裂隙扩展。PF对灌浆裂缝的延伸方向具有定向作用，并且PF的尺寸影响灌浆引起的裂隙裂缝的扩展：尺寸越大，围岩破裂越容易，通道的连接越容易形成在灌浆引起的裂隙裂缝和PF之间形成了裂缝，并且PF中的次生裂陷模式更加复杂。这表明，PFs的角度在确定灌浆引起的裂隙裂缝的延伸方向方面起着决定性的作用。通过数值模拟和实验结果揭示了不同参数岩体灌浆过程中灌浆引起的裂隙扩展。