Abstract: To release once for all the pressure in the coal seam with high rockburst risk before driving or mining, and to achieve the goal of regional rockburst prevention, the fixed-point hydraulic fracturing technique for coal seam is developed. To explore theoreticallythe feasibility and effectiveness of the fixed-point hydraulic fracturing method for coal seam rockburst prevention, a mechanical model is first developed for the coal seam, and then used to analyze, both qualitatively and quantitatively, the mechanism of the fixed-point hydraulic fracturingfor rockburst prevention. It is shown that hydraulic fracturing can prevent rockburst by increasing the resistance and releasing the energy of the coal seam.By introducing the efficiency index In, a procedure is proposed for evaluating the efficiency of the proposed rockburst prevention method, and a formulation is developed for calculating the critical volume of the bursting rockmass, providing a reference for the selection of hydraulic fracturing parameters. Finally, the proposed hydraulic fracturing method is applied to No.1412 working face of Huafeng Coal Mine, and its feasibility and effectiveness of rockburst prevention is illustrated with field observation, pipeline pressure, microseismic events and stress variation.

Key words: rockburst risk, regional rockburst prevention, hydraulic fracturing, rockburst, hydraulic fracturing efficiency index, key bumping mass