冬瓜山铜矿在进行完大规模1步骤矿房回采和2步骤矿柱回采后,形成了大量的采空区和充填采场,致使岩体应力分布十分复杂,盘区隔离矿柱的回采条件已发生根本性改变。通过对开采状态的调研分析,以52—54线隔离矿柱为例,提出了2种隔离矿柱回采方案,从开采难度、矿石回收率、采切工程量等方面进行了对比分析,并结合数值模拟软件FLAC^3D对2种矿柱回采方案进行了模拟。模拟分析显示:方案1隔离矿柱在回采过程中侧壁出现了较大的位移,容易形成侧壁垮塌,并且其塑性区面积较大;方案2在隔离矿柱回采后,采场侧壁位移很小,对于在回采过程中出现的应力集中区域,减小矿房跨度,避免矿壁受到进一步破坏,回采作业对围岩的影响最小。通过综合比较,认为方案2较为合理,为可行性较高的方案。
A large number of mined-out areas and filling stope were formed after Dongguashan copper mine finished large-scale mining of step 1 and step 2 pillars, resulting in a very complex stress distribution in rock mass. The mining conditions of panel isolated pillar had changed radically. Through the research analysis on the mining state, two stoping schemes were proposed and contrasted from aspects of mining difficulty, and mining recovery and mineral movement volume with 52-54 isolated pillar line as a case. The two stoping schemes of isolated pillar were simulated with the numerical simulation software FLAC^3D. The results showed that: in Scheme 1, side wall appears large displacement, where collapse and a large plastic zone are easily formed. In scheme 2, side wall displacement is less after recover of isolated pillars. For the stress concentration zone during stoping,it is necessary to reduce the room span and avoid the ore wall from further damage, so that the mining activities have a less impact on surrounding rock. Through comprehensive analysis on the two schemes, the scheme 2 is relatively reasonable and feasible.