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采用煤矿煤层顶板岩石作为加锚基体,用钢丝模拟锚杆,对由二者组成的加锚岩石进行了巴西劈裂、单轴压缩和压剪试验研究。结果表明,当加锚试件岩石基体出现塑性屈服裂纹开始扩展后,锚杆逐渐取代岩石基体成为外荷载的承载主体,试件的破坏特征由脆性向延性转变。加锚试件劈裂过程中,圆盘中心出现裂缝后,部分试件仍具有一定的承载能力,其抗拉强度提高了51.1%;另有部份试件则表现为迅速破坏并丧失承载能力,其抗拉强度提高了91.6%。单轴压缩试验中,加锚试件的破坏形式可分为两类:一类为裂纹平行锚杆轴向发展;另一类为裂纹垂直锚杆轴向发展,加锚试件的抗压强度提高了34.6%。加锚试件剪切过程中,其承载能力出现了明显的二次劣化现象,回归试验结果可得加锚试件的内摩擦角基本不变,而凝聚力提高了22.9%。
Coal seam roof rock is used as anchoring base, and steel wire is used to simulate anchor. The anchored rock composed of the two is subjected to Brazil splitting, uniaxial compression and compression shear tests. The results show that when the plastic yielding crack begins to expand in the anchored rock specimen, the rock bolt gradually replaces the rock matrix as the bearing body of the external load, and the failure characteristics of the specimen change from brittleness to ductility. In the process of anchoring test piece splitting, after some cracks occurred in the center of the disc, some of the test pieces still have some bearing capacity and the tensile strength increased by 51.1%; while some test pieces showed rapid destruction and loss of carrying capacity , Its tensile strength increased by 91.6%. In the uniaxial compression test, the failure modes of anchored specimens can be divided into two types: one is axial development of parallel cracked anchor; the other is axial development of vertical cracked anchor, and the compressive strength of anchored specimens Increased by 34.6%. During the shearing process of anchoring test pieces, the bearing capacity of the anchoring pieces showed a significant secondary degradation phenomenon. The results of regression test showed that the internal friction angle of anchorage test pieces remained unchanged and the cohesion increased by 22.9%.