Study on “drilling-cutting- fracturing” integrated energy dissipationtechnology for hard coal rock mass

In order to solve the problem of rockburst prevention and control of hard coal rock mass in Hulusu Coal Mine, combined with the bump characteristics of No.21103 working face, the global influencing factors and local influencing factors of working surface impact hazard were analyzed in detail, and the mechanism of bump of coal and rock mass in No.21103 working face was obtained. .The analysis shows that the hard coal seam is the main internal condition which No.21103 working surface impacts starts, the hard roof is the main external condition for the impact start of the No.21103 working face. By reducing the elastic energy in the coal and rock mass system and increasing the energy consumed during system damage, it may destroy the energy storage conditions inside and outside the system and achieve the purpose of releasing energy and reducing the possibility of bump. In view of No.21103 hard coal rock mass, the design of the hard roof hydraulic fracturing, the roof deep hole pre-cracking blasting, the roof hydraulic cutting, the hard coal large diameter drill hole release of pressure, and the coal body release of pressure blasting combined with the drill-cut-pressure integrated energy release and reduction scheme adopted hydraulic fracturing as the foundation pressure relief measure for hard roof, the large-diameter drilling of coal seam was used as the foundation pressure relief measure for hard coal body. In order to improve the pressure relief effect of coal seam, the coal bed release of pressure hole diameter was set to ø150 mm and the drill hole spacing was set to is 1 m. The coal body pressure relief blasting was used as a supplementary pressure release measure. The implementation principles included: small bore diameter, high bore density, and small explosive line density and so on. The practice results show that this technical scheme can reduce the destructive power of strong mine earthquakes, and effectively reduce the occurrence of impact geostatic pressure accidents, and achieve the effect of “releasing energy and limiting bump”, which has certain promotion value.