Abstract:
For the uncovering coal and coal and gas accidents existing in the process of close coal seam rock driving, in order to ensure the safety of heading face, the coal detection technology of twice coal detection and once gas content prediction was proposed, and test was carried out in +1 650 m concentrated transportation roadway of Hongfa Coal Mine. The research results show that the roof and floor of roadway contour of top and bottom coal seams in extension direction were fitted according to the drilling completion parameters, then inferred that the top and bottom coal seam dip angle is 13° to 18° and 5° to 13°, respectively. The thickness is 2.76 to 3.16 m and 2.64 to 3.61 m respectively. The minimum normal range with rock drift is 2.94 m and 5.23 m respectively, and the error of forecast and actual maximum is 11.1%. Six coal samples are collected in top and bottom coal seam at the same time respectively; the gas content of top coal seam is 6.588 1 to 7.998 1 m
3/t, which is 5.963 2 to 7.693 2 m
3/t in bottom coal seam.