高应力坚硬顶板深孔爆破卸压及见方效应分析OA

Under the conditions of hard roof,the working face is mined to the goaf to form a"square",which is easy to cause the structural instability of the overlying strata and induce rock burst.Deep-hole blasting in roof is an important means to prevent rock burst.However,there is currently insufficient research on the impact of deep-hole blasting on pressure relief in the"square"areas.This study takes the hard roof of N2107 working face in Yuwu Coal Mine as the engineering back-ground,and develops the deep-hole blasting technology for the roof.It adopts microseismic monitoring,drilling stress and drilling debris monitoring to evaluate the pressure relief effect of two goaf"square"periods.The results show that roof deep-hole blasting plays a positive role in preventing rock burst.During the two goaf"square"periods,there are no large energy events in the microseismic monitoring,and the drilling stress monitoring and drilling debris monitoring are stable within the safe range.The goaf"square"shows the pressure manifestation characteristics of the"square"effect.The energy of micro-seismic events in local areas approach the warning value,and the drilling stress maintaining an upward trend.We propose optimization suggestions for pressure relief in the goaf"square"to ensure timely access to dynamic pressure information and improve pressure relief effect.