不少金属矿山由于前期民采在井下遗留下大小不一的众多空区,其中某些采空区体积多达数万立方米,暴露面积达数万平方米,是造成大规模冲击地压及塌陷隐患的主要诱因。为保证下部及相邻中段安全回采,提出在合理水平实施废石充填,形成应力隔离层。以某金矿为例,采用数值模拟手段研究了大采空区充填前后围岩应力及剪应变增量情况。分析计算结果表明,充填处理后,大采空区围岩应力集中程度明显减小,拉应力区域相应减少且值较小,剪应变增量值减小且剪应变增量区域不贯通,安全隐患得到消除。
Due to previous unlicensed mining in many metal mines,many different sized mined-out areas are left underground.And volume of some large mined-out area could reach to 10000 m3 and 10000 m2 square meters are exposed.It is the main reason of causing large-scale rock burst and collapse hazard.To order to guarantee the safe stoping of underneath and the adjacent level,waste rock filling carried out on the reasonable level,then the stress layer formed was proposed.Taken a gold mine as an example,stress and shear strain increment situation of surrounding rock before and after large mined-out area filling were researched by numerical simulation method.Numerical results indicate that surrounding rock stress concentration of large mined-out area decreased obviously.Tensile stress area decreased accordingly and the value was little.Value of shear strain increment decreased and the area of shear strain increment were unconnected after filling treatment,and the potential safety hazard was eliminated.