充填体荷载作用下金属矿山采空区顶板稳定性分析

针对如何提高研究区深部矿体采矿活动安全性的问题，通过理论计算方法和数值模拟计算法对采空区顶板的稳定性进行了分析。结果表明，厚跨比理论、载荷传递交汇线理论和结构力学梁理论求得的采空区顶板安全厚度基本一致，具有较好的线性变化关系，获得采空区顶板安全距离为10.0～18.0 m(采空区跨度为20 m);通过数值模拟极端后，确定了研究区顶板的临界破坏厚度为12.5 m,最终确定了采空区顶板的安全厚度为15 m。此时，采空区的水平方向最大的位移量可达28.2 mm,垂直方向上最大下沉量可达368 mm;采空区开挖后的最小主应力为-1.42 MPa,最大主应力为-6.7 MPa。

Stability analysis of goaf roof in metal mine under backfill load

Aiming at how to improve the safety of mining activities in deep ore bodies in the research area，the stability of the roof of the mining area is analyzed by theoretical calculation method and numerical simulation calculation method.The results show that the safety thickness of the goaf roof obtained by the thickness-span ratio theory，the load transfer intersection line theory and the structural mechanics beam theory is basically the same，and has a good linear change relationship，and the safe distance of the goaf roof is 100~180 m（the goaf span is 20 m）.After numerical simulation of the extremes，the critical failure thickness of the roof in the study area was determined to be 125 m，and the safety thickness of the roof in the goaf area was finally determined to be 15 m.At this time，the maximum displacement of the goaf in the horizontal direction can reach 282 mm，and the maximum sinking amount in the vertical direction can reach 368 mm，the minimum principal stress after excavation of the goaf is -1.42 MPa，and the maximum principal stress is -6.7 MPa.