基于采充时序的空场嗣后充填体强度要求优化研究

为解决江西某钨矿空场嗣后充填法一步骤采场充填体强度要求优化设计问题,以该矿开采技术条件为基础,利用加拿大米切尔法进行了强度要求解析计算,并基于实际采充时序过程,考虑充填体与矿岩接触作用、二步骤采场非胶结充填体对一步骤采场胶结充填体侧向推力作用,提出了充填体强度要求修正解析方法,并计算了同等条件采场充填体强度要求,进而采用FLAC3D开展采充时序过程中一步骤采场充填体强度要求数值解的搜索计算,对比分析了充填体强度要求数值解与两种解析解,讨论了米切尔法的适用性,校验了修正解析模型可靠性,可为同类矿山充填体强度要求优化计算提供参考。

Optimization of backfill strength requirement in open stoping with subsequent backfill mining method after considering excavating and filling sequences

For optimization of cemented backfill strength in primary stopes of a Tungsten mine in Jiangxi Province where open stoping with subsequent backfill mining method is utilized, firstly Mitchell analytical model was employed to calculate the required strength based on parameters of stope dimensions and backfill properties in this mine. Then a modified analytical solution has been proposed after considering actual sequences of excavating and filling, in which influences from the interaction between backfill and surrounding rock together with the lateral pressure from uncemented backfill in adjacent secondary stope on back wall of exposed cemented backfill in primary stope. The strength requirement was evaluated with the new proposed analytical solution based on the same parameters. Furthermore, numerical modellings were carried out with FLAC3D to simulate excavating and filling processes to search for the minimum required strength. And the numerical solution for backfill strength requirement was compared with the above two analytical results for the discussion of applicability of Mitchell method and the validation of reliability of new proposed solution. The modified analytical model and the numerical search method in this study after considering actual excavating and filling sequences can be a good guidance for the optimization of the backfill strength requirement in other similar mines.