冲击危险巷道锚杆支护防冲原理解析

Analytical analysis of anti-impact mechanism of bolt supporting for bump-prone roadways

为揭示锚杆支护对冲击地压的防治原理,基于失稳理论进行锚杆支护巷道冲击地压解析,探究锚杆支护间排距对冲击地压发生的临界阻力区、临界载荷以及冲击释放能量的影响规律。结果表明,对于脆性岩体,锚杆支护间排距对冲击地压影响微弱;对于塑性岩体,随着锚杆支护间排距减小,冲击地压发生的临界阻力区、临界载荷与冲击释放能量逐渐增加,且这种规律随着岩体冲击倾向性降低越发明显。从临界阻力区与临界载荷角度看,降低锚杆支护间排距,能够增加冲击地压发生难度,但锚杆支护间排距降低导致冲击释放弹性能增加,冲击破坏能力提升。因此,应在弹性区与塑性区交界处设置吸能结构吸收多余的弹性能,从而削弱冲击能对锚固岩体的破坏力。

Based on the instability theory, rockburst in circular tunnel supported by bolts was analyzed. And effects of bolt interval on the critical resistance zones depth, critical impact load size and the release of energy of rockburst were discussed. The results show that when the burst tendency of coal is moderate, with the increase in bolt density, the depth of critical resistance zone, the critical load and release energy become greater, and the phenomenon is more obvious as burst tendency decrease. However, it has unconspicuous effects when the burst tendency of coal is very strong that increase in bolt density makes rockburst more difficult, but the release energy become greater which cause the stronger damage of rockburst,and that in practical projects, the energy absorption structure absorbing redundant elastic energy should be installed in the vicinity of the elastic rock zone and in the broken rock zone so that destructiveness of impact energy acted on bolted rock mass can be weakened.