长周期扰动应力下盘区柱内巷道锚杆支护动态响应规律

长周期扰动应力下盘区柱内巷道稳定及盘区柱整体稳定是大规模开采的关注重点。采用数值模拟方法,构建了大规模、多中段、长周期强烈开采扰动下的数值模型,建立了锚杆支护的拉伸破断、剪切破断数值力学模型,研究了不同水平、不同阶段回采过程中盘区柱内巷道锚杆支护的受力特性和盘区柱围岩的应力和塑性区发展特征。研究结果表明:不同开采阶段不同开采水平的锚杆轴力和巷道顶板变形响应明显,锚杆剪力由于变形监测部位的限制响应程度甚微,盘区柱内巷道稳定性好。盘区柱内巷道围岩偏应力场与塑性区动态演化仅在前两个中段开采时反应强烈,大规模开采结束时盘区柱仍然能够保持正常稳定。分析方法及分析结果能够对盘区柱内巷道稳定及盘区柱整体稳定做出提前预判,为盘区柱的正常使用提供安全保障。

Dynamic Response Rule of Rockbolt Support of Drift in the Panel Pillar with Long-period Induced Stress

Under long-period induced stress, the stability of the drift in the panel pillar and itself are the focus of large-scale mining. Numerical simulation method was used to construct a numerical model which suffers from a large-scale, multi-middle, long-period mining-induced stress, and a numerical mechanics model of tensile and shear fracture for the rockbolt support was established. The mechanical characteristics of the rockbolt support for the drift in the panel pillar, the developing characteristics of the stress around surrounding rockmass and its plastic area were studied at the different mining levels and processes. The research results show that the axial forces of rockbolts and the roof deformation of the drifts were obviously responded at different mining levels and processes, and the shear forces of the rockbolts was very small due to the limitation of monitoring sites. The dynamic evolution of the deviatoric stress field and the plastic area of the surrounding rockmass in the panel pillar only reacted strongly during the first two mining middle, and the panel pillar remained stable at the end of the large-scale mining. The analysis method and results can predict and evaluate the stability of the drift in the panel pillar and itself in advance, and provide safety guarantee for the normal use of the panel pillar.