点柱分层充填法的点柱间距优化与稳定性分析

Optimization on the Pillars Spacing and Analysis on Stope Stability of Cut-and-fill Method with Pillars

某黑色金属矿山的点柱式上向分层充填法,在开采过程中垂直走向的点柱间顶板经常发生垮塌现象,导致采场无法正常回采,甚至造成永久损失。针对此问题,在原点柱尺寸及沿走向间距布置不变的前提下,利用FLAC3D软件对垂直走向点柱间距不同的3个方案进行研究,分析了不同间距布置条件下点柱间顶板的应力、应变分布及变化规律,并采用安全系数法为判据分析了顶板的稳定性。结果表明:点柱沿垂直走向间距7m时,顶板安全性好且每个矿块可多回收矿石1.5万t,为最优方案。

The upward cut-and-fill method with pillars was used in a ferrous metal mine. During the mining, collapse ac- cidents frequently occurred in the roof between pillars along the vertical trend, which resulted in unnormal recovery and permanent losses. According to the problem, based on the same origin pillars size and pillars spacing along trend, three schemes with different pillars spacings distributing along the vertical trend were researched by FLAC3D. The distribution and change rule of stress and strain in the roof were analyzed under different spacings. And the roof stability was analyzed by safety factor method. The results showed that when the pillars spacing along the vertical trend was 7 m for the best scheme, the roof stability was good and each ore block could recycle more 15,000 t of ore.