Study on water conductive zones in the roof and floor strata induced by mining of coal seam group under enriched aquifers

摘要

To insure a security mining of coal seam group under enriched aquifers, the height of water conductive fracture zones in overlying strata and the depth of fracture zones in floor strata are calculated, the fracture distribution with respect to the main aquifers and coal seam group was elaborated. The width of waterproof coal pillar when rich water quaternary is on one side of work-face is theoretically determined. The fracture features in the roof and floor of the coal seam group are analyzed by using of UDEC2D numerical simulation. The results show that there is small disturbance on quaternary if an adequate width of waterproof coal pillar is used for protection. Much attention should be paid on K7 and K5 sandstones which are the main enriched aquifer strata. The effective measures should be employed in advance to prevent and control water inflow particularly when the thick coal seams of No.3 and No.6 are extracted.