Water drainage law in No. 8 coal seam roof of Donghuantuo Coal Mine

ZHENG Yan; MA Ya-jie; ZHANG Chang-jiang; WANG Dong

doi:10.11799/ce201701020

Abstract：In order to optimize the layout and design of drainage boreholes, enhance the drainage efficiency, the water drainage law was studied for No. 8 coal seam roof in No. 2 north district of Donghuantuo Coal Mine. Theoretical analysis was carried out on the water enrichment law of water-filled aquifers in No. 8 coal seam roof under the control of syncline structure. Statistics was done on water drainage yield of 32 drainage drillings and 6 influence factors. Yield-time dynamic feature, and correlation coefficient between drainage yield and influence factors were studied. The results show that, the mining fracture zone will conduct the aquifers above No. 5 coal seam; aquifers 0~30m above No. 5 coal seam are drained to decrease its water head of geological structure developed, hydraulic connection is good along the dip and poor along the strike of stratum. It is appropriate to arrange drill socket scattered along the roadway, while staggered in upper and lower roadway. Among the 6 indicators, borehole location and the initial drainage time have the most significant effects on borehole water yield. The relationship between borehole direction and the fracture strike direction also have significant effect on borehole water yield. Advance drainage time shall be 8 to 10 months.