Study On The Failure Law Of Top And Bottom Plates In Close Coal Seam Group Mining

Through the close distance coal seam group in different mining sequences repeated mining dynamic study, summarizing and analyzing the close distance coal seam group mining effect of roof and floor failure rules should force propagation law and displacement variation. For mine gas drainage, the deployment of mining, water prevention and control outstanding provide theoretica l basis and technical support, but also for our province near distance coal seam group mining to provide reference.Using a 2D similarity simulation experiment and the FLAC3 D numerical simulation software of Shanjiaoshu Coal Mine and Lin Hua mine close d istance coal seam group repeated mining is simulated. Through simulation of short distance coal seams repeated mining rock damage range were observed. At the same time, the repeated mining, coal seam roof and floor stress and rock movement monitoring. To compare and analyze the different simulation results, summed up in the near distance coal seam group mining rule of roof failure.Through the comparison of Shanjiaoshu Mine and Lin Hua mine close distance coal seam group repeated mining roof and floor damage summed up, seam spacing is effect of near distance coal seam group mining roof and floor damage range of the main factors, in the polar distance coal seam group downward mining, adjacent to the coal seam roof and floor have been greatly damage. In mining within the scope of influence, Repeated mining strata of roof rock lithology of the smaller appears separation layer, floor lithology smaller rock swelling and produce many tensile cracks. Repeated mining roof pressure intensity and pressure range is small. Repeated mining moving inside the surrounding rock does not appear too much new shear and tensile failure, therefore the surrounding rock pressure relief strength and rock movement are in the original on the basis of the dynamic production increased, and not repeated mining of Jane single summation.