Engineering Practice of Shock Wave Pre-cracking Technology in Overlying Hard Rock Layer in High Ground Pressure Mine
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.
shock wavepre-crackingtop-breakinghigh ground pressureoverlying hard rock
NETL
NSTL
万方数据
维普
