The practice of rock burst disaster prevention and control in the stress concentration area of Zhangshuanglou Coal Mine

The current pressure relief blasting methods are only for the coal seam roof, and there are few researches on the roof-coal-floor synergistic pressure relief blasting management, especially for the rock burst disaster prevention and control in the hard and thick sandstone roof overburden area. In order to solve the above problems, taking the 74101 working face of Zhangshuanglou Coal Mine of Jiangsu Xukuang Energy Co., Ltd. as the engineering background, this study analyzes the rock burst disaster inducing factors from the aspects of mining layout, coal rock burst tendency and sandstone overburden area stress concentration degree. This study reveals the reasons for the rock burst disaster induced by the sudden instability of coal rock mass. It is proposed that the local high stress concentration, caused by the geological conditions such as abnormal sandstone overburden area of roof, fault geological structure and hard fine sandstone of floor, is the main cause of rock burst disaster. The CT inversion technology of mine rock burst vibration wave is used to accurately detect the high rock burst risk area of 74101 working face: the transportation lane side is 75 m along the roadway and the extended working face is 60 m elliptical area; the track lane side is 60 m along the roadway and the extended working face is 80 m elliptical area. Aiming at the targeted high stress concentration areas, a precise "roof-coal-floor" synergistic pressure relief blasting technology is proposed to relieve pressure in the rock burst risk area of 74101 working face and adopt micro-seismic monitoring methods and on-site observation methods to evaluate the effect of pressure relief and rock burst prevention. The results show that after pressure relief blasting, the daily cumulative energy of mine rock burst in the hard and thick sandstone overburden area of 74101 working face is reduced from 1.57×104 J to below 104 J and the vibration frequency is reduced by 50%. Moreover, the characteristics of mine rock burst are low energy and low frequency, and rock burst risk is significantly reduced. Therefore, it is verified that the synergistic pressure relief blasting technology is applicable to the prevention and control of rock burst disasters in the hard and thick sandstone overburden area of Zhangshuanglou Coal Mine.