Evolution law of stress and energy field accumulation during the fracture of plate structure in thick and hard rock strata
;It is of great significance to master the fracture mechanism and stress and energy e-volution laws of thick and hard rock strata for preventing and controlling the dynamic disasters in deep coal mines.Based on the engineering geological conditions of the 63upper05 and 63upper06 working faces in the sixth mining area of Dongtan Coal Mine,the distribution of high-energy e-vents was analyzed combined with on-site microseismic monitoring data,and the correlation between the fracture of thick and hard rock strata and high-energy mining earthquake events was summarized.A mechanical model for the key stratum group Ⅱ thick plate structure was established,the influence of various factors on energy accumulation within thick and hard rock strata was analyzed,then the law of energy accumulation and release during the fracture of thick hard rock strata was revealed.The FLAC3D numerical simulation software was used to explore the accumulation and evolution law of stress and energy field under thick and hard rock strata,and the numerical results were verified through the high-energy event triggered during the mining process of the 63upper 05 working face.This study determined that the fracture and migration of key stratum groups was the root cause of high-energy mining earthquakes,ob-tained the maximum stress σmax of key stratum groups and the expressions of internal flexural elastic energy Ew of rock strata,and analyzed the influence of various factors on energy accu-mulation within thick and hard rock strata.The distribution characteristics of vertical stress field,horizontal stress field,and energy field under the influence of thick and hard rock strata during the mining process of the working face were clarified.The fracture law and energy accu-mulation-release evolution process of the overlying thick and hard rock strata on the 63upper05 working face were divided into five stages,namely the initial accumulation release stage of key strata group Ⅰ,the periodic failure stage of key strata groups Ⅰ and Ⅱ,the energy storage deformation stage of key strata group Ⅲ,the fracture settlement stage of key strata group Ⅲ,and the settlement deformation stage of key strata group Ⅳ.The research results can provide theoretical and technical support for the prevention and control of dynamic disasters in deep coal mine under thick and hard strata.
thick and hard rock stratastrong mine earthquakerock fracturethick plate structureenergy accumulation
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