露天转地下开采时境界顶柱的最优厚度研究

摘要

许多露天矿山的后期会面临由露天开采转地下开采设过渡问题。通过在露天坑底留设境界顶柱可以保障露天开采与地下开采的同时进行。然而，境界顶柱的留设会给地下开采的安全带来隐患：如果境界矿柱留设过薄，易造成境界顶柱突然塌落，反之会造成资源浪费。以马鞍山铁矿3号矿体露天转地下开采的实际工程为研究对象，借助FLAC3D软件进行正交数值模拟试验，依据试验结果通过多元线性回归的方法，建立了能够反映各影响因素综合作用下的境界顶柱最优安全厚度的数值预测模型，获得了不同剖面下境界顶柱的最佳厚度。可为类似工程设计时参考。%Many opencast mines will face the transition from open-pit mining to underground in their late stage . The arrangement of boundary crown pillars in the bottom of open pit can guarantee the simultaneous operation of the open-pit and underground mining .However ,boundary crown pillars will bring potential danger to the safety of under-ground mining:if the boundary pillars are too thin ,they are prone to sudden collapse; and if thick,a waste of re-sources.This paper has taken the practical engineering of No.3 Orebody of Maanshan Iron Mine as the research sub-ject.With the help of FLAC3D software to carry out orthogonal numerical simulation experiments ,and on the basis of the experimental results ,numerical prediction model reflecting the optimal safety thickness of boundary crown pillars under the comprehensive influence effect is established by multiple linear regression method .And the optimal thick-ness of different profiles of boundary pillar has been obtained .References can be provided for similar projects .