Evaluation of water inrush risk from coal seam floors with an AHP-EWM algorithm and GIS

As coal mining is extended to ever-greater depths, the factors affecting the safe mining of coal seams are becoming increasingly complicated. High-pressure confined water in the coal seam floor can pose a major threat to the safety of coal mining. Therefore, based on the analysis of various factors that affect water inrush from coal seam floors, this study develops a geological engineering model of high-pressure confined water damage assessment for coal mine face floors. The model adopts six evaluation factors: coal mining depth, coal seam thickness, thickness of the aquiclude, hydrostatic pressure, brittle-rock thickness, and the distribution of faults and folds. The comprehensive weight of the six factors is obtained through analytic hierarchy processing (AHP) and the entropy weight method (EWM) to establish an AHP-EW risk index model (AEM). AEM is applied for the evaluation of two coalfaces in a study area in North China, and the water inrush risk zonation of the coalface floors is determined. Finally, the results given with AEM are compared with those from the traditional water inrush coefficient method, and its applicability in other mining areas is also validated. The results show that the proposed model provides more accurate evaluation results than the traditional method and that its application is more practical.