Comprehensive Evaluation of Water-inrush Risk from Coal Floor by Both Water-inrush Coefficient and Fuzzy Cluster Methods

Based on comprehensive analysis of the influence factors of water-inrush risk from seam floor,this paper extracted the key indexes for evaluating water-inrush risk from seam floor.The paper introduced the comprehensive method of fuzzy cluster to evaluate the water-inrush risk from seam floor in order to solve the limitations in evaluation of water-inrush risk from seam floor by the method of water-inrush coefficient.The method of fuzzy cluster gave a comprehensive consideration of many influence factors and it solved the problems of critical values in evaluation by the method of water-inrush coefficient.By taking the lower group of coal seams in No.11 mining area of Nantun Mine as an example,this paper extracted the mining depth,the thickness of water-resisting layer and water pressure as the key indexes,and conducted a comprehensive evaluation on the water-inrush risk from seam floor by both water-inrush coefficient and fuzzy cluster methods,so this has important guiding significance for the prevention and control of water in Ordovician limestone during mining of the lower group of coal seams of Nantun Mine.