Risk evaluation of water inrush from seam floor during mining of lower group in Zhaizhen coal mine

For mining lower group of coal safely in Zhaizhen coal mine, have used multi-originated information complex to evaluate risk of water inrush from seam floor during mining. This paper analyzed main factors which affect water inrush from seam floor with the function of multi-originated in Surfer to modify the method of water inrush coefficient and built up model of water inrush index adapt to coal mine. The coal mine was divided into three areas, danger zones, relative danger zones and safe zones with the model. The results show that water inrush from floor is a result by various elements working together, water yield property of floor confined aquifer play a decisive role, geologic structure play a control action, hydraulic pressure and mining pressure are the dynamic condition, aquifuge takes the restriction effect. Guiding mine the lower group coal safely in Zhaizhen coal mine by district results.