基于FLAC^(3D)分析的某铁矿充填效果研究

Research on filling effect of an iron mine based on FLAC^(3D) analysis

为解决辽宁某铁矿开采后地表沉陷问题,验证自研的复合激发尾砂胶结充填体充填效果,运用FLAC^(3D)模拟软件对铁矿二步骤充填开采和地表沉陷进行数值模拟计算研究。研究结果表明:采用3种胶结充填体分别进行二步骤充填后,盐基、碱基、水泥基胶结充填体内部的应力平均值分别为0.92,0.79,0.93 MPa,最大位移值分别为38,22,75 mm,说明碱基胶结充填体在改善采场应力环境、减小顶底板变形情况具有一定的优势;以对采空区充填的模拟结果来看,碱基复合激发胶结充填体对围岩具有良好的支撑作用,能够很好地改善地表沉降现象;通过对采场应力和地表沉陷进行为期1 a的跟踪监测,表明监测区域位移变化量基本稳定,且全年监测点位移变化形态与应力变化趋势相同。

In order to solve the problem of surface subsidence after mining of an iron mine in Liaoning,and verify the filling effect of self-developed composite excitation tailings cemented filling body,the FLAC^(3D) simulation software was used to carry out the numerical simulation calculation on the two-step filling mining and surface subsidence of iron mine.The results showed that after the two-step filling with three types of cemented filling body,the average stress in the salt-based,alkali-based and cement-based cemented filling body was 0.92,0.79 and 0.93 MPa,respectively,and the maximum displacement was 38,22 and 75 mm,respectively,which indicated that the alkali-based cemented filling body had certain advantages in improving the stress environment of stope and reducing the deformation of roof and floor.According to the simulation results of the goaf filling,the alkali-based composite excitation cemented filling body had good support effect on the surrounding rock,which could improve the surface subsidence well.Through the one-year tracking monitoring of stope stress and surface subsidence,it showed that the displacement change of the monitoring area was basically stable,and the change pattern of displacement at the monitoring point throughout the year was the same as the change trend of stress.