超千米竖井岩爆防控对策研究

针对深竖井施工中的岩爆问题,以弹性应变能、平均能量释放率、塑性区体积为评价指标,研究不同掘进速率、竖井掌子面实施不同应力释放孔方案及井壁有无锚喷支护情况下围岩的能量释放与聚集情况等,得出降低掘进速率可以降低施工中的平均能量释放率;掌子面周边均匀布置应力释放孔,可以更好降低掌子面后方的应力集中,引导掌子面在主动释放较少能量的情况下在其周围形成较大的低压破碎区;对井壁进行锚喷支护,可减小井壁的位移,降低开挖后井壁围岩的能量释放速率。以上三种方式相辅相成,各自从不同的角度、位置出发,整体对岩爆的发生进行调控,可为深竖井的顺利施工提供有益指导。

Study on the countermeasures for the prevention and control of rock burst in the over-kilometer shaft

In view of the problem of rockburst during the construction of deep shaft, the elastic strain energy, average energy release rate, and volume of plastic zone are used as evaluation indicators to study the energy release and accumulation of surrounding rocks under the conditions of different bore speeds, different stress relief hole schemes are implemented on the shaft face, and whether the shaft wall is supported by anchor and shotcrete. It is concluded that reducing bore speed can reduce the rate of the average energy release during construction; The uniform arrangement of stress release holes around shaft face can better reduce the stress concentration on the shaft face, and lead to form a large low-pressure crushing zone around the shaft face under the condition of less energy release. By bolting and shotcreting support, the displacement of the shaft wall can be reduced, that means, the energy release rate of the shaft wall after excavation can be reduced. The above three methods complement each other, starting from different angles and positions, and regulating the occurrence of rockburst as a whole, which can provide useful guidance for the smooth construction of the deep shaft.