【摘要】 冲击地压、大变形或分区破裂化正成为我国深部开采的难题.高地压是导致冲击地压、大变形或分区破裂化的根源.钻孔爆破卸压是转移或释放高地压的有效措施.以厂坝铅锌矿灰岩为样本,应用FLAC3D静态模拟巷道掘进中巷帮钻孔卸压的钻孔间距、钻孔深度及有无孔底爆破的卸压效果.研究表明:巷道埋深越深,支承压力越大,钻孔间距也将越大;钻孔深度介于支承压力峰值与支承压力区最大宽度所处的位置之间;仅钻孔而不孔底爆破的卸压效果不明显.上述研究规律应用于文峪金矿、豫灵镇某万米平巷和东桐峪金矿的灰岩、大理岩巷道掘进,成功控制了岩爆飞石.巷道穿过无岩爆倾向的岩石,如煌斑岩时,尽管不会发生岩爆,但是将它们的钻孔间距、钻孔深度较岩爆倾向地段增大0.5~1.0 m并类似孔底爆破,可以确保支承压力持续向围岩深部转移或部分释放,避免巷帮因应力集中而发生开裂或片帮.更多还原

【Abstract】 Rockburst, large deformation and zonal fracturing are becoming technical problems for deep mining in China. High ground pressure is the root cause of rockburst, large deformation and zonal fracturing. Moreover drilling and blasting pressure relief is an effective measure for transferring the abutment pressure peak to deep rock masses and release part concentrated stress. Taking Changba lead-zinc mine limestone as a sample, the drilling space and depth for drilling pressure relief in tunnel wall, and the effects of stress relief with and without bottom-blasting are numerically simulated by FLAC3 D. Research shows that the deeper overburden, the greater abutment pressure, and the borehole space should be larger. The drilling depth for blasting pressure relief lies between the position of abutment pressure peak and the maximum width of abutment pressure zone. In addition, the pressure relief effect is insignificant as compared with drilling without borehole bottom blasting. The control measures following the above mentioned research rules are applied at limestone and marble tunnels in Wenyu gold mine, a myriameter adit in Yuling town and Dongtongyu gold mine. Though rock burst does not occur when tunnelling in no burst-prone rock masses, such as lamprophyre, due to their borehole space and depth increasing 0.5~1.0 m than the location where distressing is needed, it can also reach an ideal effect making sure the abutment pressure transferred to the deep or is partly released, and the tunnel wall cracking or spalling at the stress concentration are avoided by the similar borehole bottom explosion applied in burst-prone zone.更多还原