综采工作面过陷落柱毫秒延时松动爆破研究与应用

Research and Application of Millisecond Delay Loosening Blasting during Fully Mechanized Working Face Passing Collapse Column

为了解决3203综采工作面过陷落柱困难的问题,结合陷落柱现场地质条件,提出基于毫秒延时起爆技术的松动爆破专项方案,并采用理论设计、数值模拟和现场试验相结合的方法,对比总结同时起爆模型和毫秒延时起爆模型的裂隙扩展模式和应力传播规律,分析在顶板处质点的振速和位移变化规律。研究表明:通过毫秒延时松动爆破可以使相邻炮孔间形成贯通裂隙,相比于同时起爆,延时起爆模型优先创造自由面,从而破碎陷落柱岩石并减少爆破飞石,解决了综采面过陷落柱困难的问题。毫秒延时起爆相比于同时起爆,对顶板的峰值合振速减小了9 cm/s,对顶板的峰值合位移减小了0.095 mm。现场试验发现,松动爆破对陷落柱的破碎效果明显,陷落柱岩石强度得到有效减弱。实践证明,毫秒延时松动爆破技术能够极大提高截煤作业效率,保护采煤区顶板,经济效益显著。

To solve the difficult problem of passing the collapse column in 3203 fully mechanized working face,combined with the geological conditions of the collapse column,a special program of loosening blasting based on millisecond delay detonation technology is proposed.Meanwhile,adopting the combination of theoretical design,numerical simulation,and field test,the fracture expansion mode and stress propagation law of the simultaneous detonation model and millisecond delay detonation model are compared and summarized and the change rules of vibration velocity and displacement of the mass points at the top plate are analyzed.The study shows that millisecond delay loosening blasting can make the adjacent boreholes form penetrating cracks,compared with the simultaneous detonation,the delay detonation model gives priority to the creation of the free surface,thus crushing the collapse column rock and reducing the blasting flyrock,and solving the difficult problem of passing the collapse columns in the fully mechanized working face.Millisecond delay detonation compared to simultaneous detonation,the peak combined vibration velocity of the roof plate is reduced by 9 cm/s,and the peak combined displacement of the roof plate is reduced by 0.095 mm.Field tests have found that the effect of loosening blasting is obvious in the crushing of collapse columns,and the strength of the collapse column rock has been effectively weakened.The practice has proved that the millisecond delay loosening blasting technology can greatly improve the efficiency of coal-cutting operations,and protect the roof of the coal mining area,with significant economic benefits.