金川矿山深部采掘条件下岩石力学研究与实践

STUDY AND PRACTICE OF ROCK MECHANICS IN JINCHUAN MINE UNDER DEEP EXPLOITATION

金川矿山经过几十年开采,开采深度已达1 000 m,复杂的工程地质条件、高地应力以及高渗透压导致深部开采工程的稳定性问题愈加突出。对金川二矿区深部850～1 000 m水平进行大量的现场地质调查研究,测试深部典型岩石的物理力学参数、膨胀与软化特性,研究岩石力学性质和地应力随埋深的变化规律。采用岩体地质力学(RMR)分类法和岩体质量(Q值)分类法,绘制二矿区深部各分段水平的岩体质量分区图。在深入调查金川矿区深部巷道变形和破坏特征的基础上,对高地应力、高渗透压下深部巷道开挖支护稳定性进行研究,结果表明,U型钢和锚杆联合支护效果最佳。全面总结金川矿区深部巷道支护经验,对巷道掘进和支护技术提出几点新的想法。研究不同开采方式对金川矿区深部充填体和围岩稳定性的影响,优化矿体回采方式,建议采用"隔三采一"布置回采进路,有助于控制围岩的变形,减弱上部充填体的下沉。

After decades of exploitation in Jinchuan mine, mining depth has reached to 1 000 m. Due to complex geologic condition, high geostress and high hydraulic pressure, the stability of deep mining engineering is a crucial problem. A large number of field geological surveys of 850 - 1 000 m level in Jinchuan No.2 mining district are carried out. Physico-mechanical parameters, expansion and softening properties of deep typical rock are measured. The change laws of rock mechanics and geostress with mining depth are analyzed. By using geological mechanics（RMR） classification method and rock quality（Q value） classification method, zone maps for quality classification of rock mass in Jinchuan No.2 mining district are plotted. Based on the deep surveys of deformation and failure characteristics in deep roadway in Jinchuan mine, the stabilities of deep roadway excavation and supporting under high geostress and high hydraulic pressure are studied. The result shows that coupled U steel-anchor supporting technology performs best. By summarizing the practice experience of supporting technique in deep roadway in Jinchuan mine, some new ideas on deep roadway excavation and supporting technologies are put forward. The influence of different extraction methods on the stability of surrounding rock and backfill at depth is investigated. By optimizing the sequence of panel mining stope of ore block, the mining sequence of the ＂three stope panels＂ is applied to the mine, which has obvious effect on controlling the displacement of surrounding rock and backfill.