深孔卸压爆破技术改变围岩应力结构的试验研究

针对围岩内高应力集中造成巷道支护后难以稳定的问题,应用"深孔卸压爆破技术",重新调整围岩应力分布,使深部围岩内积聚的弹性能以变形破裂的形式释放,使应力集中的弹性区转移到围岩更深处,在围岩深部形成应力集中的自承载圈,在巷道周围表层一定范围内形成低应力卸压圈.通过改变围岩应力分布,使围岩内高应力得到释放和转移,消除巷道附近围岩应力集中,在底板岩层中形成上自撑岩环体和下自撑岩拱体两层自撑结构,有效地控制巷道变形,保持了巷道稳定,达到深部围岩-浅部围岩-支架系统耦和支护的目的,充分发挥了围岩自承能力.卸压后的巷道采取常规支护技术就能保持长期稳定.

The Research and Experiment of Changing the Stress Structure of Wall Rock through the Technology of Blow-up and Stress-discharging in Deep Holes

This article aims at solving the instability of the timbering of laneways resulted from the concentration of the high stress of wall rock. It applies the technology of blow-up and stress-discharging in deep holes to the readjustment of the stress dis- tribution of wall rock. With the technology, the elasticity accumulated within the deep wall rock is distorted and then bursts out. Thus, the elastic area in which the stress eoncentrates is removed to the deeper wall rock and forms a circle discharging low stress on the surface of the walls of laneways. Through changing the stress eontribution of wall rock, the high stress within the wall rock is discharged and removed. As the eoncentrated stress of the wall rock close to the laneways is removed, in the rock base forms a 2-layer self-supporting structure that bears the ring rock upwards and downwards supports the vaulted rock. The self-supporting structure effectively controls the distortion of the laneways, maintains the stability of the laneways and realizes the purpose of the timbering system of deep and surfaoe wall reeks by bringing the self-supporting ability of wall rock into full play. The laneways, with the regular timbering technology, is able to maintain long-term stability after the stress is discharged. e