深部硬岩可切割性及非爆机械化破岩实践

Cutting Characteristic and Non-explosive Mechanized Rock-breakage Practice of Deep Hard Rock

为了系统地认识应力条件、矿岩特性和破岩参数等因素对深部硬岩截割特性的影响,梳理并总结了以往关于深部硬岩截割特性室内试验及非爆机械化破岩现场实践工作。根据3种应力环境对镐型截齿静态和动静组合破岩特性的影响,结合构建的截齿破岩峰值载荷理论及回归模型,发现硬岩在较低围压或无围压条件下具有安全高效的破碎表现;根据高单轴围压下截齿破岩扰动诱发岩爆的过程和机理,揭示了采矿过程中由开采扰动诱发高应力矿柱岩爆的发生机制;基于加卸荷诱导损伤、预切槽和预钻孔等人为诱导缺陷对镐型截齿破岩特性的影响研究,得到人为诱导缺陷可有效提高硬岩的可切割性,获得了改善硬岩可切割性的成套方法;现场试验了多种机械化破岩方法,提出了基于应力解除和动静组合破岩的预切槽硬岩矿体旋转振动连续截割设备及其施工工艺。研究结果可为深部硬岩矿体非爆机械化规模开采提供理论基础和现场实践经验。

The factors such as stress conditions,ore-rock properties and breakage parameters significantly affect the cutting characteristics of deep hard rock,which are also the key factors to determine the successful application of non-explosive mechanized mining.According to the three types of stress conditions of biaxial(single-face excavation),uniaxial(pillar)and low or even unconfined stress(excavation damage zone around pillar)on the rock mass near the mining operation surface,the influences of the above three types of stress conditions on the static and coupled static-dynamic rock breakage characteristics using a conical pick were systematically investigated.Combined with the established peak force theory and regression model of rock fragmentation using a conical pick,it is found that the hard rock has safe and efficient breakage performance under the conditions of low or no confining pressure.According to the process and mechanism of rock burst induced by the disturbance of rock fragmentation using conical pick under high uniaxial confining stress,the mechanism of rock burst induced by mining disturbance in high stress pillar was revealed.The effects of artificially induced defects,such as loading/unloading-induced damage,pre-slitting and pre-drilling,on rock breakage characteristics using a conical pick were investigated.The results show that the artificially induced defects can effectively improve the cuttability of hard rock,and a complete set of methods for improving the cuttability of hard rock were obtained.A variety of mechanized methods for rock breakage have been tested in the mining field,and a rotary vibration continuous cutting equipment based on pre-slitting in hard ore-rock for stress relief and usage of coupled static-dynamic rock breakage have been proposed.The above research results can provide theoretical basis and field practice experience for the large-scale non-explosive mechanized mining in deep hard rock mine.