金属矿山阶段嗣后充填采场空区破坏机理

依据和睦山铁矿现场实测资料，证明金属矿山阶段嗣后采场围岩破坏具有明显的间歇性和突发性；对其破坏机理进行了数值模拟分析。结果表明：采场顶部围岩产生卸压圈，受拉伸作用，卸压圈内岩体自重应力通过应力拱传递到矿柱上，导致矿柱应力集中出现剪切滑移破坏；其变形破坏程度受顶板、矿柱围岩稳定性以及二次开采扰动的影响。基于普氏拱理论，以矿柱为研究对象，建立了阶段嗣后采场失稳演化模型，得到了矿柱破坏方式和采场失稳演化过程：矿柱稳定阶段、矿柱大形变阶段、部分矿柱失效以及矿柱整体失效。

Failure mechanism of stope and exploited areas with stage backfill method in metal mine

According to the field investigation information in Hemushan Iron Mine,it was proved that the surrounding rock failure of stage backfill stope in metal mine was obviously intermittent and sudden change.The collapsed mechanism was studied with numerical simulation,it shows that the pressure relief ring happens in roof rock which is tensile,the stress arch transmits the stress to the top of pillar,which results in the stress concentration and shear failure of pillar.The collapsed zone mainly occurs at the roof rock and pillar,the collapsed zone area depends on the stability of the roof rock,the pillar and the disturbance are induced by secondary excavations.Based on the PU’s arch theory,taking the pillar as an object,the failure model of backfill stope was established,then the failure mode of pillar and the process of destabilization of stope were also introduced:pillar stability phase,pillar deformed phase,pillar partial failure,pillar overall failure.