尾砂充填连续开采采场顶板稳定性数值分析

Numerical Analysis on Roof Stability in Continuous Milltailings Filling Stope

针对金属矿山上向分尾砂充填连续采矿法开采条件的复杂性,通过运用弹塑性有限单元分析方法,建立平面应变数学模型,对采场顶板稳定性及采场结构参数进行分析和优化计算。结果表明,控制采场跨度或暴露面积是维系采场顶板稳定的根本措施;单层矿体开采时,随着采场跨度的加大,顶板预应力拉应力也相应增大,但伴随采高的增加,围岩内部的最大主应力、最大剪应力逐渐增大,顶板下沉量也逐渐增大,而顶板内拉应力却逐渐减小。相对1#脉脉矿体,推荐采场顶板极限暴露面积为600 m2左右,以此为基础确定的采场长、宽尺寸采场顶板稳定性最好。

For the complexity of mining conditions in metal mine continuous railings backfilling mining method,elastic-plastic finite element analysis method was adopted. The plane strain mathematical model was founded for stope roof stability analysis and structure parameters optimization design. The results showed that the fundamental measures to maintain the basic stability of stope roof was eontroling the stope span or exposed area. For single ore body minning, with the increase of stope span,roof pre-stress stress increased accordingly,and when mining height increased,the maximum principal stress and the maximal shear stress and subsidence of roof were growing larger around the stope,but the tensile stress in the roof decreased gradually. For 1^# ore body, recommend stope roof area was about 600 m^2 limit exposure. Based on this to make stope longer and wide, stope roof stability was the best.