Application and effect analysis of surface hydraulic fracturing for preventing rock bursts in thick hard roofs

YANG Guangyu; XU Gang; LIANG Shichang; LU Chuang; WANG Binchang; JIN Xin; SHENG Pengfei

doi:10.11799/ce202510004

Abstract：To address the challenges of deep-hole roof-cutting blasting technology for weakening thick hard roof strata to prevent rock bursts-such as high engineering workload,limited pressure relief range,and elevated risks-we took the No.20101 first mining face of Dahaize Coal Mine as the engineering case.Utilizing theoretical analysis and field measurements,we investigated the mechanism of surface hydraulic fracturing for rock burst prevention,identified optimal target strata,evaluated fracturing effectiveness,and analyzed the application.Key conclusions are as follows:Firstly,hydraulic fracturing generates fracture networks in thick hard roof strata,compromises their integrity,releases elastic energy in advance,thus to redistribute the high stress,reduce fracture length L,and lower the dynamic loads.Secondly,analysis of fracturing curves,water discharge from roof boreholes in the working face,and microseismic monitoring data confirms that fracturing fluid induces fractures in target strata.The fracture network extends 255.1 m along the strike direction,72.0 m along the dip direction,and 61.9 m vertically.Thirdly,compared to non-fractured conditions,post-fracturing results show reductions in total microseismic event frequency and energy by 58.95%and 67.84%,respectively.Periodic weighting intervals and dynamic load coefficients decrease by 6.3%and 10.8%,while roof collapse intensity remains stable.The findings demonstrate that ground hydraulic fracturing effectively weakens roof strata,significantly reduces rock burst risks in working faces,and achieves pressure relief in thick hard roof zones.The result provides a reference for rock burst prevention in deep mining faces in Yuheng Mining Area.