大西沟铁矿露采境界内空区顶板安全厚度研究

Study on Safety Thickness of Goaf Roof in Open-pit Mining Boundary of Daxigou Iron Mine

大西沟铁矿露天开采安全受原地下开采残留空区的影响。为确保境界内台阶开采的安全,采用4种理论计算方法和数值模拟,确定不同跨度采空区的顶板安全厚度,建立顶板安全厚度与采空区跨度的函数关系,对境界内采空区进行分类,并结合采空区顶板安全厚度确定其处置时机。研究结果表明,采空区顶板安全厚度随跨度增加呈二次函数增长,露采境界内已探知的5个空区均为简单易处理的Ⅰ类空区。当前阶段应在1343.9 m标高对2个采空区进行处理,未来应在1368 m标高对2个采空区进行处理,在1356 m标高对1个采空区进行处理,处理手段均为爆破崩落。研究结果为大西沟铁矿境界内采空区的安全处置奠定基础。

The safety of open-pit mining in Daxigou Iron Mine is affected by the residual goaf in the original underground mining.In order to ensure the safety of bench mining in the boundary,four theoretical calculation methods and numerical simulation are used to determine the safe thickness of the roof in different span goafs,and the functional relationship between the safe thickness of the roof and the span of the goaf is established.The goaf in the boundary is classified,and the disposal time is determined in combination with the safe thickness of the roof of the goaf.The results show that the safety thickness of the roof of the goaf increases quadratically with the increase of the span,and the five mined-out areas that have been discovered in the open-pit mining boundary are all Class I mined-out areas that are simple and easy to deal with.At the current stage,two goafs should be treated at the elevation of 1343.9 m.In the future,two goafs should be treated at the elevation of 1368 m,and one goaf should be treated at the elevation of 1356 m,and the treatment means are blasting collapse.The research results lay a foundation for the safe disposal of goaf in the boundary of Daxigou Iron Mine.