应力集中区域矿体开采过程的应力与位移监测

Stress and displacement monitoring during mining in stress concentrated areas

七角井铁矿采用分段空场法开采,在采深185m范围内形成了约350万m^3的采空区,导致2016年6月出现了一次大规模的地压活动,并在塌陷区底部的S19、S21和S27采场周围出现了应力集中现象。为了预测应力集中区域的矿体回采过程的地压变化规律,提出采用应力监测和位移监测相结合的地压监测技术。结果表明,经过半年的监测,确定了地压集中区域和相对稳定区域,根据监测结果调整了采矿方法及回采顺序,保障了应力集中区域S19、S21和S27采场的安全回采,矿石综合回收率达到74%,贫化率为18%。

The sublevel open stoping has been used in Qijiaojing iron mine, and a total of 3.5 million m3 gobs were accumulated within the mining depth of 185 m. In June 2016, a serious geostress activity was induced by the gobs, which resulted in a stress concentration around the stope S19, S21 and S27 under the subsidence area. A combination scheme of stress and displacement monitoring was proposed to predict the stress concentration during mining process. The results were beneficial to ascertain the area where tress concentrated areas and relatively stable regions after monitoring for half a year. The mining method and the stopping directions were adjusted according to the monitoring data, which insured the safe mining of stope S19, S21 and S27 in the stress concentrated areas. In these areas, the comprehensive ore recovery reached 74%, and the dilution rate was 18 %.