混凝土矿柱嗣后充填法采场稳定性监测与分析

兴隆磷矿为提高资源回收率,采用两步骤回采法,先矿柱胶结充填,后矿房废石充填。为保障作业的安全,验证胶结矿柱的强度,优化采场结构参数,采用区域的微震监测与局部的点监测相结合的方式,对胶结矿柱及顶板覆岩应力显现进行立体、实时动态监测。通过分析开采过程中获取的应力、应变及位移变化数据,得到了回采工作面前方的采动超前影响距离约为20 m;当矿房回采跨度约36 m时,覆岩累积应力集中较大,顶板局部会有冒落,但采场顶板移动诱发的应力远小于胶结混凝土矿柱强度,胶结矿柱无破坏。结果表明:采用两步骤回采嗣后充填的开采方法及采场结构参数等,能够保证采场稳定。该监测方法能够及时准确地为采场稳定性做出评价,为安全高效生产提供指导。

Monitor and Analysis of the Stability of Stope in Concrete Pillar with Subsequent Filling

In order to improve resource recovery in Xinglong phosphate mine，the two steps of cementing fill of pillar following by waste rocks backfilling at stope room are adopted.To ensure safety of operations，verify the strength of cemented pillar，and to optimize stope structural parameters，the stereo and dynamic stress of cementing pillar and roof overburden is monitored by the combination of micro-seismic monitoring and point monitoring in local.By analyzing the data of stress，strain and displacement in the mining process，the advance distance away from the impact at working face is determined to be 20 m; When mining stope span is about 36 m，the accumulated stress at roof overburden is large，mainly resulting in caving in partial roof.However，stress induced by stope roof movement is much less than the strength of cement concrete pillar，no damage on cementing pillar appeared.The results show that the two-step mining method with subsequent filling and the stope structural parameters can ensure the stability of the stope.The monitoring method can be used to evaluate stope stability timely and accurately，and provide guidance for the safe and efficient mining.