赵同彬, 邹建超, 傅知勇, 于凤海. 双节理贯通岩石锚固机理试验研究[J]. 煤炭学报, 2020, 45(9): 3065-3072. DOI: 10.13225/j.cnki.jccs.2019.0984
引用本文: 赵同彬, 邹建超, 傅知勇, 于凤海. 双节理贯通岩石锚固机理试验研究[J]. 煤炭学报, 2020, 45(9): 3065-3072. DOI: 10.13225/j.cnki.jccs.2019.0984
ZHAO Tongbin, ZOU Jianchao, FU Zhiyong, YU Fenghai. Experimental study on anchoring mechanism of double persistent jointed rock[J]. Journal of China Coal Society, 2020, 45(9): 3065-3072. DOI: 10.13225/j.cnki.jccs.2019.0984
Citation: ZHAO Tongbin, ZOU Jianchao, FU Zhiyong, YU Fenghai. Experimental study on anchoring mechanism of double persistent jointed rock[J]. Journal of China Coal Society, 2020, 45(9): 3065-3072. DOI: 10.13225/j.cnki.jccs.2019.0984

双节理贯通岩石锚固机理试验研究

Experimental study on anchoring mechanism of double persistent jointed rock

  • 摘要: 锚杆支护在矿山采动巷道裂隙围岩中应用范围不断扩大,揭示节理岩石锚固控制机理有利于提出科学合理的参数设计。采用声发射和数字散斑相关方法对45°倾角双节理岩石单轴压缩试验过程中的声发射数和变形场进行监测,建立了应力-应变曲线与声发射信号的对应关系,研究了曲线的变化特征以及声发射信号的分布规律,并分析了锚固作用对双节理岩石强度及变形特性影响。基于不同加载阶段双节理岩石表面散斑位移场分布特征和演化过程,总结了锚杆对节理岩石变形破坏模式和形态的影响规律。通过分析双节理岩石在不同阶段的变形演化特征与声发射数据活跃点位置及数据的对应关系,对试件破坏过程进行了划分。结合锚杆的变形形态,建立了压剪状态下锚固节理岩石力学模型,对其在不同加载阶段下进行受力分析,分析了双节理岩石破坏模式以及锚杆抗压剪、抑滑移锚固作用机理。结果表明:① 锚固双节理岩石可以承受较大的轴向变形而不发生失稳破坏,其起裂强度、弹性模量、峰值应变比无锚试件分别提高了30.7%,45.0%,109.9%,而泊松比仅为无锚试件的50%;② 锚固双节理岩石的破坏模式主要为断裂失稳,断裂失稳过程分为节理填充物滑动、节理面错动致裂、底部岩石起裂、上部岩石裂纹扩展、裂纹贯通5个阶段;③ 基于锚杆自身抗剪能力以及完整岩石的协同作用增强了锚固体抗压剪强度,锚杆抑制岩石基体相对滑动提高了节理岩石的变形能力。

     

    Abstract: Bolt support plays an important role in the mining of the cracked surrounding rock. The exploration of the anchorage control mechanism with joint rock would help to optimize the design of the parameters. In this study,the acoustic emission signals and the deformation fields of the double-joint rock with a 45° dip were monitored by employing the acoustic emission and digital speckle correlation method (DSCM) in the course of the uniaxial compression test. The corresponding relationship between stress-strain curves and acoustic emission signals was established to study the change characteristics of the curves and the distribution rules of the acoustic emission signals. Meanwhile, the effects of anchorage strength and deformation behavior of double-joint rock masses were analyzed. Based on the distribution characteristics and evolution process of the speckle displacement field of double-joint rock surface,the influences of bolt on the failure modes and morphologies of jointed rock were summarized. By analyzing the corresponding relationship between the deformation evolution characteristics of the double-joint rock and the position of the active signals of the acoustic emission,the failure process of the specimen was divided. Combined with the deformation morphologies of the bolt,the mechanics model of the anchored double-joint rock under the compression-shear condition was established,and the force analysis was carried out under different loading stages. The failure mode and the mechanism of anti-compression shear and restraining slip of bolt were well explored. The results show that:① By comparing with the non-anchored specimen,the cracking strength,elastic modulus,and peak strain of the anchored double-joint rock was increased by 30. 7% ,45% ,and 109. 9% ,respectively,while its passion ration was decreased by 50% ,which indicates the axial deformation capability without instable failure was enhanced;② Unstable fracture is the major failure mode of the anchored double-joint rock,which includes five stages: joint filler slip,joint surface dislocation cracking,bottom rock cracking,upper rock crack propagation,and crack penetration;③ The bolt could be not only used to improve the compression-shear strength of the anchorage by combining the bolt's shearing ability with the intact rock's synergistic collaboration,but also enhance the deformation ability of the joint rock through sharing the deformation produced by the external force and inhibiting the sliding of the rock matrix.

     

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