基于现场监测数据的金属矿地下崩落法开采覆岩冒落规律研究

Study on Caving Law of Overlying Rock in Underground Caving Mining of Metal Mines Based on Field Monitoring Data

针对大红山铁矿地下主矿体无底柱崩落法开采的实际,借助“冒落拱”理论对覆岩自然冒落与持续冒落进行了判别。基于大红山铁矿覆岩冒落的巷道观测、钻孔探测数据,得到了该矿地下开采的覆岩冒落发展过程与规律。研究结果表明:随着地下主采区矿体被不断崩落采出,覆岩会发生自然冒落与持续冒落,并最终贯通地表。在首采480 m分段,且年平均出矿量为94万m^(3)的条件下,按照覆岩的半年冒落速率,可将覆岩冒落大致分为快速冒落阶段(每半年冒落高度为68.3 m)和匀低速冒落阶段(每半年冒落高度为28.65 m)。得到了大红山铁矿崩落法开采覆岩冒落至地表的滞后时间经验公式,可为大红山铁矿露天与地下联合开采动态优化时空开采顺序提供指导。

In view of the actual situation of non-pillar caving mining of the main underground ore body in Dahongshan Iron Mine,the theory of caving arch was used to distinguish the natural caving and continuous caving of overlying rock.Based on the roadway observation and borehole detection data of overlying rock caving in Dahongshan Iron Mine,the development process and law of overlying rock caving in underground mining were obtained.The results show that with the continuous caving and mining of the ore body in the main underground mining area,the overlying rock will experience natural caving and continuous caving,and finally penetrate the surface.Under the condition of the first mining of 480 m sublevel and the average annual output of 9400o00 m^(3),according to the half-year caving rate of the overlying rock,the overlying rock caving can be roughly divided into the rapid caving stage(the caving height per half year is 68.3 m)and the uniform low-speed caving stage(the caving height per half year is 28.65 m).The empirical formula of the lag time of overlying rock falling to the surface in caving mining of Dahongshan Iron Mine was obtained,which can provide a guidance for the dynamic optimization of space-time mining sequence in open-pit and underground combined mining of Dahongshan Iron Mine.