Study on reconstruction of unsteady flow aquifer and determination of roof group hole drainage point

Taking Baotashan sandstone aquifer in Shicaocun Coal Mine as the engineering background, a three-dimensional visualization model of the aquifer is constructed, and the visualization model is validated by single and porous unsteady flow models. The position of the roof drainage point is estimated by invert calculation. The results show that: the unsteady flow model data of the roof group holes in the mining area agree well with the measured water discharge from the observed holes, the model has high reliability; the optimal solution of aquifer numerical reconstruction can be divided into six zones, it is Ⅰ high permeability medium water storage zone, Ⅱ medium permeability high water storage zone, Ⅲ high permeability high water storage zone, Ⅳ low permeability medium water storage zone, Ⅴ low permeability low water storage zone, Ⅵ medium permeability medium water storage zone; the water drainage point of the well is located between G1-1 and F1-3 observation point, and the water drainage is 150 m³/d to 200 m³/d.