不良充填体间隔下盘区二步骤采场回采稳定性分析

Stability Analysis on Panel Secondary Stopes Mining Separated by Poor Backfill

针对厚大矿体盘区一步骤采场回采边界欠规整、充填体质量差等问题,为了确保二步骤采场稳定和回采作业安全,开展了区域工程地质调查与分析,采用数值模拟方法对提出的两个二步骤回采优化方案进行对比,并引入破坏接近度指标(FAI)对二步骤采场回采稳定性进行定量分析和评价。结果表明:为降低二步骤回采对一步骤不良充填体的扰动影响,采取“增加回采工艺循环次数,减小单次回采结构参数”的总体思路是合理的,其中方案Ⅱ(高分层回采分层充填采矿法)对采场顶板和侧帮不良充填体的变形和塑性破坏控制效果最佳;二步骤采场区域绝大部分为低扰动至损伤区(FAI<2.0),侧帮局部破坏区最大深度为2.23 m,方案Ⅱ回采扰动下二步骤采场总体稳定性良好。研究成果可为矿山类似条件下二步骤采场安全回采提供参考。

Aiming at the problems of irregular mining boundaries and poor backfill quality of primary stopes in large and thick ore bodies,the regional engineering geological survey and analysis were carried out,numerical simulation was used to compare and select the proposed secondary stoping schemes,thus to ensure the stability of secondary stopes and the safety of the mining operation.The failure approach index(FAI)was introduced to analyze and evaluate the stability of the secondary stopes quantitatively.The results show that,to reduce the disturbance effect of secondary stoping on the poor backfill of primary stopes,the overall idea of increasing the cycle times of the stoping process and reducing the structural parameters of single stoping is reasonable,and the schemeⅡ(high-layer cut-and-fill stoping method)has the best control effect on deformation and plastic failure of the stope roof and poor backfill on the side walls.Most of the secondary stoping areas belong to the low-disturbance or damage zone(with FAI<2.0),and the maximum depth of the local failure zone on the side walls of stopes is 2.23 m.The overall stability of the secondary stopes is good under the mining disturbance in SchemeⅡ.The research results can provide a reference for safe stoping under similar conditions.