再生岩体受扰动后易松散、破碎,但在支护作用下再生岩体仍具有一定的承载能力,尤其是峰后承载能力有明显的改善。为研究再生岩体承载特性及巷道支护对再生岩体承载能力的影响,设计了再生岩体单轴加载的四因素混水平正交试验,分析再生岩体承载机理,并基于正交方差分析,检验了锚杆间距、杆径、锚固长度及金属网对再生岩体峰后弱化趋势及承载能力的显著性。结果表明:无支护和部分锚杆支护条件下再生岩体在单轴加载出现压剪破坏,部分锚杆支护再生岩体呈劈裂破坏,金属网约束再生岩体试件呈塑形滑移破坏;再生岩体破裂后的峰后残余强度具有波动性特征,峰后承载阶段稳定性取决于多裂隙面的摩擦效应,支护强化摩擦效应抵抗破碎块体在外载荷作用下的滑移、错动;金属网对再生岩体峰后承载能力影响显著,锚杆参数的变化仅对再生岩体的强度弱化趋势产生影响。
After being disturbed, the regenerated rock mass is prone to looseness and fragmentation, but under the support effect, the regenerated rock mass still has a certain bearing capacity, especially with significant improvement in post peak bearing capacity, which is the foundation for controlling the stability of the regenerated rock mass roadway. To study the bearing characteristics of recycled rock mass and the influence of support on the bearing capacity of recycled rock mass, a four-factor mixed level orthogonal test was designed for uniaxial loading of recycled rock mass. The bearing mechanism of recycled rock mass is analyzed. The significance of anchor spacing, rod diameter, anchor length, and metal mesh on the post peak weakening trend and bearing capacity of recycled rock mass is tested based on orthogonal analysis of variance. The results show that: Under the conditions of no support and partial anchor support, the regenerated rock mass undergoes compression shear failure under uniaxial loading, while some anchor support regenerated rock mass undergoes splitting failure, and the metal mesh constrained regenerated rock mass specimen undergoes plastic sliding failure. The residual strength of the regenerated rock mass after fracture exhibits fluctuating characteristics. The stability of the post peak bearing stage depends on the friction effect of multiple fracture surfaces, and the support reinforcement friction effect resists the sliding and dislocation of the broken block under external loads. The metal mesh has a significant impact on the post peak bearing capacity of the recycled rock mass, while the change in anchor rod parameters only affects the weakening trend of the strength of the recycled rock mass.
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