大体积充填体下胶结充填法回采进路参数优化研究

为了提高金川二矿区深部下向进路式胶结充填法开采效率,针对大体积充填体下大断面进路生产的安全可行性问题,通过弹塑性理论和三角塌落拱理论计算充填体人工假顶均布荷载,并依据简支梁理论和薄板理论对深部850 m水平中段回采进路宽度进行理论计算,在现有回采进路参数基础上,设计了9组不同回采进路参数的试验。通过数值模拟,分析了各组参数下进路断面的应力、位移、平均屈服率变化特征和采场安全系数,以生产效率及开采安全为目标,得出金川二矿区深部大体积充填体下的胶结充填法回采进路宽度可增加至6 m、分层高度可增加至4.5 m。现场局部试验结果表明,增大参数后的进路顶板和两帮稳定性较好,能满足安全生产的需要。

Parameter Optimization for Stoping by Cemented Backfilling Below Massive Filling Body

In order to improve the mining efficiency of underhand cemented backfilling method in the Jinchuan №2 mining area, the uniformly distributed load of the artificial roof of the filling body was calculated by using the elastoplastic theory and the triangular collapsed arch theory in view of the safety and the feasibility of the access drift with large cross section below massive filling body. And the width of the stoping drifts at 850 m level in the middle horizontal section of the mine was calculated theoretically based on the simply supported beam theory and the thin plate theory. Based on the existing parameters of the stoping drifts, 9 groups of testing schemes with different drift parameters were designed. By numerical simulation, the variation characteristics of stress, displacement and average yield rate, and safety factors of the stoping drift were analyzed for the different schemes. For achieving a certain production efficiency and ensuring mining safety, it is determined that the stoping drifts for the cemented backfilling, which is below the massive filling bodies in №2 mining area, should have its width increased to 6 m and its slicing height increased to 4.5 m. Field tests with these parameters have proven that both the roof of the stoping drifts and the two sides of the stope are highly stable, meeting the requirement of safe production.