“V型”切槽顶板闭合方法研究

On the roof closure method resulting from the “V”-shaped top-grooving

针对某萤石矿的薄脉急倾斜采空区,提出"V型"切槽顶板闭合法,即应用爆破技术在采空区上盘实施"V型"切槽,引起采空区闭合或形成自然平衡拱,从而消除上部采空区。借助材料力学推导了"V型"槽凿岩爆破位置的设计方法。应用有限元仿真了该采空区处理方法的力学原理。结果表明,"V型"切槽能引起采空区上盘向下盘移动,从而引起采空区闭合或形成自然平衡拱。该采空区处理方法技术可行,经济合理,简便适用。

This paper aims to introduce a renovated roof-closure method developed by its authors to deal with the thin and steep slanting forsaken stopes in the mining area. To be exact, the ＂V＂ groove is supposed to be excavated by blasting technology at the top of forsaken stope and make the forsaken stope closed or form a naturally balanced arch. In so doing, the top plate of the forsaken stope can therefore be removed. The method here mentioned known as the ＂V＂ groove drilling and blasting is actually deduced by application of material mechanics. Wherefrom, the method is simulated by the finite element approach. The results of our use of the method demonstrate that it can cause the upper plate removal to the plate beneath, and forsaken the stope next to it so as to result in a natural balanced arch. In doing so, it becomes possible to achieve the purpose of the forsaken stope disposal so as to form a the horizontal distance （L） of tunnel （about 10 m） from the edge of the forsaken stope, and then the tensile area of the top plate could be further broadened. In the moderate rock mass, the method can ensure the tunnel stable. Otherwise, L must be 20 m if the tendency of forsaken stope along the vertical direction is not overturned. Theories and techniques to be applied are all characteristic of advanced nature, which are surely expected to bring about reasonable economy, confident safety and great economic benefits.