空场嗣后充填开采法矿房数值模拟分析与参数优化

Study on room parameter optimization of open-stope subsequent filling mining in fluorite mine

针对近地表萤石矿房(埋深仅8.34 m)开采所导致的顶板及地表沉陷问题,建立了矿体开采摩尔-库伦模型,通过数值分析,针对开采扰动对上覆岩层的影响进行了研究,得到了不同开采方案下顶板位移沉降值及应力分布,综合模拟结果进行分析,由于矿房开采宽度减小,出现应力集中现象,导致10、8、6、4 m矿房宽度开采阶段顶板最大垂直应力基本呈递增趋势。结合位移分析结果可知,由于埋深较浅及顶板悬露跨度大幅减少的原因,最终使应力的小幅增长未对顶板沉降产生更大的影响,顶板沉降量与矿房宽度仍呈正比关系。在支护条件下,4 m宽度方案开采推进至30 m左右位置时,顶板及地表都会发生一定的沉降。为近地表矿体的地下开采参数选择提供了一定的指导意见。

In this paper,aiming at the problem of roof and surface subsidence caused by near-surface fluorite room mining,the Mohr-Coulomb model of ore body mining is established.The influence of mining disturbance on overlying strata is studied by numerical analysis,and the displacement settlement value and stress distribution of roofs under different mining schemes are obtained.The comprehensive simulation results are analyzed.Due to the decrease in the width of the room mining,the stress concentration phenomenon occurs,which leads to the increase of the maximum vertical stress of the roof of the 10,8,6,and 4 m room width mining schemes.Combined with the displacement analysis results,it can be seen that due to the shallow buried depth and the large reduction of the roof hanging span.Finally,the small increase in stress does not have a greater impact on the roof settlement,so the roof settlement is still proportional to the width of the mine.Under the supporting conditions,when the mining of the 4 m width scheme is advanced to about 30 m,the roof and the surface will have a certain settlement.