| Roof caving is one of the common disasters in mine production, so the study of evaluating stability of roof and analyzing destruction characteristic of superincumbent stratum during mining process is of vital importance to safety production. The major coal roof of Wugou coal mine were chosen to be the research objects in this article. Sedimentologic factors affecting coal roof stability were analyzed synthetically, and also the vertical sequence of sedimentary facies were analyzed. The development degree of folds, faults and other geological structure in mining area were analyzed according to exploration drilling, geophysical prospecting and production data. Rock structure of coal roof was divided by fractal dimension values as characteristic quantity. Rocks in1021working face of No.10coal roof were took to have a test in physics mechanical properties.After the weight of factors that affected roof stability were determined with the AHP method, research area was divided into several units, then by using the overlay function of GIS, the stability types of coal seam roof were divided into several units comprehensively. The result showed unstable region of roof on No.10coal seam was mainly distributed in south-two mining area, first mining area and south middle area, occupying about25%of the whole area.The roof of No.82coal seam was mainly distributed by unstable area, occupying about70%of the whole area.The changes of stress field and displacement promoting to different stages from open-cut eye in the rock of1021working face on No.10coal seam were accurately reflected with FLAC3D,and the destruction characteristic of superincumbent stratum was analyzed too. The result showed Max vertical stress at roof above goaf was more than15MPa with the working face promoting continuously.The height of caving zone in roof was from7m to8m, and the height of fractured zone was from29m to36m. |
PDF Full Text Request