Partitioning prediction on the risk of water inflow in the first mining area of Zhangjiamao mine

In the light of the surfacing cracks and the shortage of water resources problems resulted from mining of Zhangjiamao mine. According to analyses of water-filling factors for the first mining area, this paper selects the formula in the Standard on the Exploration of Hydrogeology and Engineering-Geology in the Mining Area (GB12719-91) ( Standard for short) to calculate the heights of water flowing fractured zone at coal seam No.4^-2, 5^-2 respectively, and draws up two roof-breaking safety division maps. On the basis of the goaf water and the surface gully water, a scientific risk evaluation system for the roof water-bursting condition during mining coal seam No. 4^-2, 5^-2 is established, and a division scheme for the condition is also put forward in the paper, which provides basis for carrying out “The twelfth five-year plan” of the mine.