Analysis of Factors Influencing Floor Water Inrush in Coal Mines: A Nonlinear Fuzzy Interval Assessment Method

A nonlinear fuzzy interval method for risk assessment of floor water inrush in coal mines was established, consisting of a multi-index evaluation system and a computational model. The multi-index evaluation system is formed by the destination, criteria, and indicator layers and the risk levels of floor water inrush were divided into five grades. Geological structure, hydrologic condition, the state of the floor aquifuge, and the mining condition were analyzed. Thirteen factors were considered as assessment indices. A computational model is proposed based on nonlinear fuzzy mathematics and the analytic hierarchical process (AHP). Considering the uncertainty of evaluation indices obtained from field exploration, the interval number was adopted to represent variables. Gaussian membership function was used to determine the membership function and membership degree, and the 1–9 AHP scales method was used to calculate the interval number judgment matrixes. The final evaluation levels were obtained by the relative superiority analysis method. The proposed method was successfully applied to the 13301 working face of the Wanglou mine and four additional coal mines in China. The results were highly consistent for these practical situations, which verify the reliability of this study.