Water inrush mode and countermeasures for Zhengzhou mining area

In order to reduce risks of water-inrush during coal production, water inrush modes are analyzed and countermeasures of the corresponding mode are put forward based on the systematical research. On the basis of 21 cases of coalmine accident which took place in Zhengzhou mining area, water-inrush mode is classified. According to channels, it can be divided into 3 categories and 4 sub-categories, respectively; Countermeasure are put forward in terms of corresponding mode of water inrush. The results indicate that three modes, which are fault-induced mode, fold-induced mode, and mining-fracture-induced mode, are classified according to channels of water inrush. Then according to the fault size and spatial relationships of strata, fault-induced mode is further divided into four sub-classes, which are roof-fissure-induced mode of slide tectonic, direct-docking-aquifer-induced mode in medium and large fault zone, thickness-thinning-aquifuge-induced mode in medium and large fault zone, and small-fault-induced mode, respectively. In addition, the water inrush mode is further divided into goaf-water-induced mode and high-pressure-aquifer-induced mode. Besides, electronic methods, including transient electromagnetic method and high-density electric method, are the prerequisite countermeasure for the water-inrush mode.