深孔爆破切顶对沿空留巷围岩稳定性影响的研究

Study on influence of advanced deep-hole blasting pre-splitting roof on stability of gob side entry retaining

为了在山西省南阳煤矿3207工作面顺利实施沿空留巷无煤柱开采,在靠近巷旁支护墙的采空区侧进行超前深孔爆破预裂顶板,通过数值模拟计算和现场工业试验,进行了深孔爆破切顶对沿空留巷围岩稳定性影响的研究。以南阳煤矿3207工作面运输巷沿空留巷为背景,构建了数值模拟计算模型,计算了留巷的顶、底板位移和墙体、煤帮的位移,分析了留巷围岩的应力分布与变化。数值计算表明,切顶后沿空留巷围岩应力和位移的减小幅度较大,围岩稳定性显著提高。现场工业试验研究表明,深孔爆破切顶能有效地消除悬臂梁顶板对留巷围岩的旋转挤压破坏,有助于沿空留巷结构保持稳定和完整。

In order to smoothly implement gob-side entry retaining and mining without coal pillar in 3207 working face of Nanyang Coal Mine,Shanxi Province,this paper proposes to carry out advanced deep-hole blasting pre-splitting roof near gob side supporting wall.Through numerical simulation and field industrial test,the influence of deep-hole blasting roof cutting on surrounding rock stability of gob-side retaining roadway is studied.Based on the backdrop of retaining roadway along goaf in 3207 working face of Nanyang coal mine,a numerical simulation model was established,the displacement of roof and floor,wall and coal body of retained roadway,the stress distribution and variation of surrounding rock of retaining roadway were calculated.The numerical calculation shows that the variation of stress and displacement of surrounding rock in gob-side retaining roadway decreases greatly after roof cutting,and the stability of surrounding rock is improved significantly.The field industrial test results show that deep-hole blasting roof cutting can effectively eliminate the rotational extrusion damage of cantilever beam roof to surrounding rock of gob-side retaining roadway,and help to maintain the stability and integrity of gob-side retaining roadway structure.The research results of this paper can be used for reference in the design and construction of gob-side entry retaining project.