充填体下水平矿柱回采方案研究

安庆铜矿在生产过程中为确保高中段回采安全,在-385~-400 m之间留有约15 m厚的水平矿柱。随着开采深度加大,预留矿柱量越来越多,为最大限度地回采矿石,现对水平矿柱进行回采。根据工程实际情况,对水平矿柱的回采方法提出上向中深孔嗣后充填,下向中深孔嗣后充填,上向进路分层充填3种方法,3种方法在回采效率和安全性上进行对比,着重考虑回采过程安全性,建议采用上向进路分层充填法进行回采。同时,针对上向充填法的回采顺序提出中间向两翼,左端向右端,右端向左端,两翼向中间等4个方案,耦合surpac与FLAC3D构建矿区数值模拟分析模型,对该4个方案在-385 m中段进行开挖模拟运算。分析结果得出:两翼向中间回采方案垂直位移量最小、最大拉应力较小、塑性区域最小,为最优回采方案。

Study on Stoping Scheme of Horizontal Pillars under the Back-fill

A horizontal pillar with 15 m of thickness was kept between -385 and -400 m to ensure the stoping safety of high or medium section during production period in Anqing copper mine.With the mining deepening，more and more pillars are reserved.It's going to excavate these horizontal pillars in order to recover copper mine as much as possible.Three mining plans including upward medium length hole stopping with subsequent back-fill，downward medium length hole stopping with subsequent back-fill，and upward drift stopping method are proposed for the horizontal pillar mining according to the real working situation.These three plans are contrasted from its efficiency and safety，especially safety.The upward medium length hole stopping with subsequent back-fill is recommended because of its safety.Four kinds of excavation orders are given for this plan，showing as from the middle to the side，from the left to the right，from the right to the left and from the side to the middle.Then，mine numerical model is created based on FLAC3D and Surpac software to calculate the four excavation processes at -385 m.The analysis shows that the vertical displacement，principle stress and plastic distribution are minimum by adopting the excavation order from the side to the middle.So it is the optimal scheme.