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基于注浆锚固裂隙砂岩单轴压缩试验结果,研究了不同锚固作用下裂隙砂岩破裂模式,探讨了锚杆根数以及预应力对裂隙砂岩破裂特征的影响,分析了含两根锚杆裂隙砂岩变形破坏过程中裂纹萌生、扩展和演化规律。结果表明:随着锚杆根数增加,裂隙砂岩最终宏观破裂模式趋于复杂,对30°裂隙倾角而言,试样逐渐由拉伸破裂过渡到拉剪混合破裂模式;而对45°裂隙倾角而言,试样逐渐由剪切破裂过渡到拉剪混合破裂模式。预应力抑制了裂隙岩样中拉伸裂纹的扩展和延伸,使得呈现的裂纹数显著少于无预应力条件下试样的裂纹数。最后以典型锚固裂隙砂岩试样为例,分析了变形破坏全过程中裂纹扩展特征。注浆锚固裂隙砂岩具有显著渐近破裂特点。
Based on the uniaxial compression test results of grouting anchored fissured sandstone, the fracture modes of fissured sandstone under different anchorage were studied. The influence of the number of anchors and prestressing on the fracture characteristics of fissured sandstone was discussed. The deformation of fissured sandstone with two anchors was analyzed Crack initiation, propagation and evolution in the failure process. The results show that the ultimate macro-fracture mode of fractured sandstone tends to be complicated with the increase of the number of anchors. For the 30 ° fracture angle, the specimen gradually transitions from tensile fracture to mixed shear mode; while for 45 ° fracture angle In terms of, the specimen gradually transition from shear fracture to shear shear mode. Prestressing suppresses the extension and extension of the tensile crack in the fractured rock specimen, so that the number of cracks present is significantly less than that of the specimen without the prestressing force. Finally, taking the typical anchored fractured sandstone sample as an example, the crack propagation characteristics in the whole process of deformation and failure are analyzed. Grouting anchor fractured sandstone has the characteristics of asymptotic collapse.