A research on increasing mining upper limit is important for coal mining

which can fully utilize coal resources and release most of the mines from the tension of limited successive exploitation. Based on the hydrologic and geologic data and data of nearby mines

taking the N2601 working face of Tianzhuang Mine for example

water resources of the producing area and water-existing character of the floor are analyzed; based on the plastic strain of the cover rock

the height range of caving zone and water flow fractured zone are analyzed through numerical simulation; finally

the upper mining limit is obtained by synthesizing the numerical simulation and exploitation regulations.