露天转地下嵌入式复合型人工境界矿柱构建

Construction of Embedded Compound Artificial Boundary Pillar from Open-pit to Underground Mining

针对传统方法处理露天坑底的矿量损失大、隔离效果差等缺陷,提出采用地下开采方法对露天坑底的矿体进行回采,铺设底部结构,使用混凝土充填采空区,构建露天转地下矿山嵌入式复合型境界矿柱的新方法.利用嵌入式复合结构对充填体进行连接,在完成进路假底铺设、进路充填、进路与围岩间、进路与进路间、进路与沟槽间的锚固连接后,形成完整的覆盖矿体的10m厚的人工境界矿柱.数值计算表明,嵌入式复合型人工矿柱的施工过程对于边坡的应力场与塑性区影响不大,不会对边坡的稳定性产生影响.工程实践表明,嵌入式复合型人工矿柱铺设的同时对矿体进行回收,回收率可达95%,铺设的境界矿柱密闭性良好,具有隔水、防洪、承压能力,能很好地隔离露天地下相互影响.

Considering the disadvantages of traditional methods,such as great mine loss of open-pit bottom and bad isolation effect,an embedded compound artificial pillar that is used during the transition from open-pit to underground mining is designed.This method is to employ the underground mining method to extract the open-pit bottom,to lay out bottom structure and then to fill the mine-out area with concrete.It tends to connect the obturator with the embedded compound structure,to accomplish the man-made bottom layout access road,to backfill the access road and to anchor the rockmass between access road and rocks,between access and grooves and among access roads.Therefore,the 10 m thick complete artificial boundary pillar,covering the whole ore body,may be finished.Numerical calculation shows that the implementation procedure of the embedded compound artificial pillar may not exert great influence on the stress field of slopes and plastic zone,which means no harm to the slope stability.Engineering practice demonstrates that laying out embedded compound artificial pillar while exploring the ore body may lead to a recovery rate of 95%.The accomplished boundary pillars enjoy sound impermeability,waterproofness,flood control and load-bearing capability.This may perfectly isolate the interactive influence between open-pit and underground mining.