岩爆灾害控制的动静组合支护原理及初步应用

PRINCIPLE AND PRELIMINARY APPLICATION OF COMBINED STATIC-DYNAMIC SUPPORT TO ROCKBURST DISASTER CONTROLLING

目前岩爆支护理论研究以岩石准静力学理论为基础,存在一定局限性。从围岩结构效应的角度,分别探讨外界扰动和岩爆围岩本身诱发岩爆的动力学机制,外界扰动易在围岩破裂区和弹性区交界处发生应力波反射拉伸破坏,岩爆是满足一定条件下围岩内部自稳时变结构调整的过程,提出岩爆支护的结构时变控制原则。现有支护措施下岩爆动力学破坏特征表现为洞室表面岩体层裂剥离造成锚杆托板悬空,基于此,进一步提出岩爆灾害控制的动静组合支护原理,相应提出预留锚固方式、动静组合锚杆等关键技术,强调锚杆可伸长构件应设置在围岩体内部破裂区和弹性区边界附近,从而给应力波扰动破坏的弹性区岩石提供扩容变形空间,同时,锚固的杆尾能对层裂岩石提供补强作用。通过深部矿井岩爆巷道的现场初步应用,该支护技术能取得良好的防治效果。

There are certain limitations in the current theory of rockburst supporting based on static rock mechanics. The dynamical mechanism of rockburst caused by the external disturbance and the surrounding rock itself was discussed from the perspective of structural effect of surrounding rock. The external disturbance may easily lead to the damage of the elastic rock zone adjacent to the broken rock zone because of the reflection wave of stresses. Rockburst can be regarded as the adjustment process of self-sustained time-varying structure of surrounding rock under certain conditions. A principle of controlling the time-varying the structure in supporting was put forward. With the present supporting measures, the surface rocks of underground cavern would spall and peel and the bolt pallets would hang in the air after the happening of rockbursts. A static-dynamic combined supporting method to control the rockburst disaster was put forward with the key techniques of anchoring reservation and static-dynamic combined bolts. The extensible components of bolts should be installed in the vicinity of the elastic rock zone and in the broken rock zone; so that enough spaces may be provided for the dilatancy and deformation of rocks in elastic zone damaged by the reflected stress waves. Meanwhile, the tail of the anchoring rod can strengthen the broken zone rock. The preliminary application to a deep rockburst roadway, it is proved that the new technology of supporting is effective in the prevention of rockburst.