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针对岩爆巷(隧)道树脂锚杆锚固机制研究的不足,利用真三轴加卸载试验系统,开展了两种加载模式下的具有岩爆倾向性的树脂锚杆锚固硬岩试样在一侧约束情况下的双轴压缩试验。分析和探讨了树脂锚杆锚固体岩爆破裂演化及锚固控制。结果表明,在逐级连续加载模式下,锚固体试样产生了小幅度应力降,没有垫板约束的部分可见明显裂纹并呈现层裂现象,观察锚固体内部断面发现锚固体本身基本完好;在逐级断续加载模式下,试样发生整体成层爆裂,小直径锚杆发生断裂,随着锚杆直径的增大,锚固体在控制层爆方面的效果越明显,可用岩爆控制的锚杆组合梁理论来解释其锚固机理;锚固体呈现出比较小的应力松弛现象,是试样内部能量传递、吸收和耗散变化调整的结果,在加载后期一旦应力松弛过程存在非弹性变形极易诱发岩爆;两种加载模式下树脂锚杆锚固体破裂演化不同,原因在于锚杆锚固体内部能量传递和吸收的程度不同。
Aiming at the shortcomings of research on bolt anchoring mechanism of rock burst tunnel (tunnel), a three-axis loading and unloading test system was used to test the rock bolt anchorage hard rock samples with rock burst tendency under two loading modes. Biaxial Compression Test with Side Constraints. The evolution of rockburst and anchorage control of resin bolt anchors were analyzed and discussed. The results show that under the successive loading mode, the specimens have a small amplitude of stress drop, and the obvious cracks and the phenomenon of delamination can be observed in the part without the constraint of the backing plate. The anchoring body itself is basically intact observed in the internal section of the anchoring body. In the step-by-step loading mode, the whole layer bursts and the small-diameter anchor breaks, and as the diameter of the anchor increases, the effect of the anchor in controlling the layer explosion is more obvious. Rod composite beam theory to explain the anchoring mechanism; anchor showed a relatively small stress relaxation phenomenon is the result of energy transfer within the sample, absorption and dissipation changes in the final stage of stress relaxation process once there is inelastic deformation easily Induced rockburst. The fracture evolution of resin anchor under two loading modes is different because of the different degree of energy transfer and absorption inside the anchor.