切顶高度对巷旁支护沿空留巷稳定性的影响

Effect of cutting roof height on the stability of gob-side retaining roadway with roadside support

为了研究深孔爆破切顶高度对混凝土巷旁支护沿空留巷稳定性的影响,以南阳煤矿3207工作面皮带巷沿空留巷工程为背景,采用离散元UDEC软件数值模拟计算和分布式监测手段,监测测点变量随顶板垮落到稳定的连续变化值和测线变量在顶板测线长度范围内的数值,经分析得到3207工作面的合理切顶高度,结合实践经验的其他爆破参数,进行现场试验和应用。结果表明,切顶能有效消除基本顶悬臂梁对留巷结构的挤压破坏,合理的切顶高度使留巷围岩稳定性得到增强。最后提出在较薄直接顶、厚煤层综放开采条件下,采用超前深孔爆破切顶巷旁混凝土沿空留巷技术是可行的。

In order to study the effect of cutting height of deep-hole blasting on the stability of retained entry supported by gob-side support wall,with the retained entry of 3207 working face in Nanyang Coal Mine as the engineering background,the discrete element UDEC numerical simulation calculation and distributed monitoring method have been used to monitor the continuous variation of measuring point variables with roof collapse to stability and the value of measuring line variables in the range of measuring line length of roof.Through analysis,the reasonable cutting height of 3207 working face has been obtained.Combined with other blasting parameters of practical experience,field test and application have been carried out.The results have shown that the roof cutting can effectively eliminate the extrusion damage of the basic roof cantilever beam on the retained roadway structure,and the reasonable roof cutting height can enhance the stability of the retained roadway surrounding rock.Finally,it is put forward that under the condition of fully mechanized top-coal caving mining with thin direct roof and thick seam,it is feasible to adopt the technology of retaining roadway along goaf by advanced deep hole blasting.