Classification and prediction of water inrush risk from coal seam floor with deep coal seam mining under lake

To evaluate the risk of water inrush from Ordovician confined aquifer in the western No.161 mining area of Binhu Coal Mine, based on the analysis of the geologic and hydrogeological characteristics of the mining area, five factors were selected as the main control factors of water inrush prediction of coal seam floor, inclu ding the water pressure of the Ordovician aquifers, fault density, the distribution of fault intersections and end points, fault scale index, effective water impermeable floo r thickness, the thematic map and the homogenization map were made, and an evaluation model of water inrush index was established, the risk levels were predicted b y regions and levels respectively.Results showed that, according to the value region of water inrush index n>0.46, 0.562n>0.43, 0.432n>0.35, 0.352n>0.23, nS0.23, the risk level of Ordovician limestone water inrush was divided into extreme danger area, dangerous area, dangerous area with some risks, dangerous area with lttle risks and safe area.It was proved that the prediction results were in accord with reality, and the evaluation results were similar to the water inrush coefficient, were more deta iled and more consistent with the actual situation.The results of classification could help to guide the prevention and control of water hazard during mining.