为防止深井坚硬顶板沿空留巷的充填墙体在顶板垮落时被压坏,特采取深孔爆破强制放顶来释放顶板压力以提高沿空留巷的护巷效果。通过数值模拟和理论分析的方法,阐述深孔爆破强制放顶的卸压机制。炸药在坚硬岩体中爆破,爆破孔周边的岩体受爆轰应力波作用产生大量裂隙并发生大幅度位移,使爆破孔周围的应力重新分布,厚层顶板垮落,降低了巷旁充填墙体的附加载荷,从而起到护巷作用。最后,在潘一矿东区1252(1)工作面进行超前深孔爆破强制放顶的现场应用,在经历工作面回采和充填留巷稳定阶段后,墙体整体维护效果良好,对类似条件下沿空留巷强制放顶具有很好的借鉴意义。
In order to prevent the filling wall along gob-side entry retaining being crushed when roof caves in deep well, the deep borehole blasting forced roof caving was taken to release the roof pressure and improve the supporting roadway gob-side entry retaining effect. The pressure relief mechanism of deep borehole blasting to forced roof caving was expounded by numerical simulation and theoretical analysis method. After dynamite blasting in hard rock, the surrounding rock of blasting boreholes produces a large number of fissures and the significant displacement by the explosion stress waves; and stresses were redistributed. So the additional load of filling body and the deformation of the surrounding rock were reduced which play the role of supporting roadway. Finally, in the working face 1252(1) of eastern area of Panyi coal mine, the deep borehole blasting was applied to forced roof caving field test; and the filling wall kept stable after mining. It provides a good reference for gob-side entry retaining under similar conditions.