冲击波预裂工艺技术在高地压矿井上覆硬岩层的工程实践

Engineering Practice of Shock Wave Pre-cracking Technology in Overlying Hard Rock Layer in High Ground Pressure Mine

高地压矿井煤层采空后上覆硬岩层容易造成悬顶等动力灾害隐患,常规的治理方式效果欠佳,亟需探索一种新型的工艺技术来实现顶板灾害绿色治理。提出高位定向钻孔+可控冲击波长距离断顶工艺技术,通过专用设备对岩层进行单点多次冲击破碎,进而实现致裂岩层的目的。对某矿顶板坚硬岩层进行先导性试验,设计1个高位定向长钻孔,预裂作业每隔10 m冲击1次,每点冲击10次;采用1个穿层顶板窥视钻孔来检验预裂效果。试验结果表明:愈靠近定向聚能棒裂缝的形态愈发育且呈递减趋势,初步确定上覆岩层的有效预裂半径为10 m。通过效果对比试验证明,该技术在顶板灾害治理中技术可行,值得推广。

The overlying hard rock layer in the coal seam of high earth pressure mine is easy to cause the hidden danger of dynamic disaster such as hanging roof.The conventional treatment method is not effec⁃tive,so it is urgent to explore a new technology to realize the green roof disaster treatment.The technology of high directional drilling+controlled shock wave for long distance top-breaking is put forward,which can be used to break the rock layer multiple times by single point through special equipment,so as to realize the purpose of cracking the rock layer.A pilot test was carried out on the hard rock in the roof of a mine.A high directional long borehole was designed.The pre-cracking operation struck once every 10 m and 10 times at each point.A peep hole through the roof was used to test the effect,and the pre-cracking effect was ana⁃lyzed.A pilot test was carried out on the hard rock in the roof of a mine.A high directional long borehole was designed.The pre-cracking operation struck once every 10 m and 10 times at each point.A peep hole through the roof was used to test the pre-cracking effect.The experimental results show that the shape of the fracture is more developed and decreasing the closer it is to the oriented shaped rod.The effective prefrac⁃ture radius of the overlying rock is determined to be 10 m.The results show that the technology is feasible and worth popularizing in roof disaster control.