Large-space mining in multiple working faces in deep mines leads to frequent large-energy strong mine earthquakes,while the surface is accompanied by severe subsidence and deformation.Mastering the spatial and temporal distribution response law of surface movement and strong mine earthquakes under specific stratum con-ditions is of great significance for the prevention of dynamic disasters in deep mines.Based on the engineering circumstances of the 63upper04,63upper05 and 63upper06 working faces in the Dongtan Coal Mine of Yanzhou Min-ing Area,the complex geological strata are scientifically classified using the Key Stratum Theory and the princi-ple of composite failure.Field measurements are conducted to investigate the surface subsidence patterns and the spatiotemporal distribution characteristics of strong mining-induced seismicity during multi-working face mining under the deep and hard rock layer.The evolutionary patterns of the key stratum group during the continuous min-ing of multiple working faces is analyzed,revealing the interactive effects among key stratum group failure,sur-face subsidence patterns,and the distribution of large-energy strong mining-induced seismic events.The main conclusions are as follows:(1)The geological strata in the Dongtan Coal Mine Six Mining Area can be divided into four key stratum groups,each comprising one key stratum and several hard rock layers.Compared to a single key stratum,the seismic energy is higher and the failure step distance is larger when a key stratum group experi-ences composite failure,resulting in a more pronounced impact on the movement of overlying rock layers and surface subsidence.(2)The observation results of surface subsidence show that the surface subsidence coeffi-cients of the 63upper04 and 63upper05 working faces are 0.189 and 0.458,respectively,and the 63upper06 working faces have been mined for 808.29 m,and the surface subsidence coefficient is 0.492,which is much smaller than the average surface subsidence coefficient of other mines in Yanzhou mining area(0.75-0.85)due to the geologi-cal characteristics of multiple key layer groups.Also,the surface is not fully mined,and the subsidence sequen-tially changes from no obvious subsidence,significant subsidence,to the trend that the subsidence space is gradu-ally increasing.(3)During the mining of 63upper04 working face,the strong mine earthquake events with large energy are mainly concentrated near the low key strata group Ⅰ and Ⅱ.With the continuous mining of multiple working faces,the large-energy strong mine earthquake gradually shifts to the high level.gradually concentrated near the second and third layers of the key strata.(4)According to the measured data of surface subsidence and high-energy strong mine earthquakes,the composite cracking overburden structure of the key layer group under the continuous mining of multiple working faces of the No.6 mining area of Dongtan Coal Mine changs between"fault-suspended"structure and"hinged"structure,and the layer-by-layer evolution process verifies that there is a certain linkage effect between overburden movement,surface subsidence and high-energy strong ore earthquake.The research results have a certain guiding significance for the study of compound fracture of multi-key strata and the pre-control of high-energy strong mine earthquakes under similar engineering geological conditions.
key layer groupscompound fracturestrong mine earthquakessubsidence of the earth's surfacemi-gration of overburden rocklinkage effect
国家科技期刊平台
NSTL
维普
万方数据
