“横切-纵爆”复合卸压机制研究与应用

    Research and application of combined pressure relief technology of roof hydraulic fracturing and deep hole blasting

    • 摘要: 为实现赵庄煤业1311工作面高强度复合顶板顺利垮落,避免大面积悬顶诱发强矿压灾害,分析了“横切-纵爆”复合卸压机制,即爆破裂纹二次扩展半径r在压裂损伤长度R和暴轰裂纹半径a0的基础上大幅增加,提升了顶板预裂效果;在1309工作面工业性试验的基础上,合理确定了“横切-纵爆”卸压工艺参量,并开展现场应用。结果表明:“横切-纵爆”复合卸压工艺,能够增加钻孔轴向裂隙和钻孔径向裂隙密度,应用区域巷道顶板离层量较低;“横切-纵爆”卸压工艺能够有效破坏了顶板完整性,降低了巷道围岩应力集中程度,对强矿压灾害起到防治效果。

       

      Abstract: In order to realize the smooth collapse of high-strength composite roof in 1311 working face of Zhaozhuang Coal Industry company and avoid strong ground pressure disaster caused by large-area roof suspension, firstly, the composite pressure relief mechanism of “cross cutting and longitudinal explosion” is analyzed theoretically, in other words, the secondary propagation radius r of blasting crack is greatly increased on the basis of fracturing damage length R and explosion crack radius a0, which improves the effect of roof pre-cracking, then, based on the industrial test of 1309 working face, the pressure relief process parameters of “cross cutting and longitudinal explosion” are reasonably determined and applied in the field. The results show that: the “cross cutting and longitudinal blasting” composite pressure relief process can increase the density of borehole axial fractures and borehole radial fractures, and the roof separation of roadway in the application area is low; it shows that the “cross cutting and longitudinal blasting” pressure relief process can effectively destroy the integrity of the roof, reduce the stress concentration of the surrounding rock of the roadway, and play a preventive effect on the strong ground pressure disaster.

       

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