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

• Xintong Wang
• Shucai Li
• Zhenhao Xu
• Peng Lin
• Jie Hu
• Wenyang Wang
Technical Article

## Abstract

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.

## Keywords

Risk assessment Fuzzy mathematics Interval number AHP Weight

## Zusammenfassung

Es wurde ein nichtlineares Fuzzy-Intervall-Verfahren zur Risikobewertung von Bodenwassereinbrüchen in Kohlebergwerken etabliert, das aus einem Multi-Index-Bewertungssystem und einem Rechenmodell besteht. Das Multi-Index-Bewertungssystem besteht aus Ziel-, Kriterien- und Indikator¬schichten, wobei die Risikostufen für Bodenwassereinstrom in fünf Stufen unterteilt sind. Die geologische Struktur, der hydrologische Zustand, der Zustand der Bodenaquifuge und der Abbauzustand wurden analysiert. Dreizehn Faktoren wurden als Bewertungsindizes berücksichtigt. Ein Berechnungsmodell wird basierend auf nichtlinearer Fuzzy-Mathematik und dem analytischen hierarchischen Prozess (AHP) vorgeschlagen. Unter Berücksichtigung der Unsicherheit der aus der Feldforschung gewonnenen Bewertungsindizes wurde die Intervallnummer zur Darstellung von Variablen übernommen. Die Gauß‘sche Zugehörigkeitsfunktion wurde verwendet, um die Zugehörigkeitsfunktion und den Zugehörigkeitsgrad zu bestimmen. Die 1−9 AHP-Skalen-Methode wurde verwendet, um die Intervallzahl-Beurteilungsmatrizen zu berechnen. Die endgültigen Bewertungsstufen wurden durch die Methode der relativen Überlegenheit erhalten. Die vorgeschlagene Methode wurde erfolgreich auf der 13301-Arbeitsfläche der Wanglou-Mine und bei vier weiteren Kohlebergwerken in China angewendet. Die für diese praktischen Situationen gewonnenen Ergebnisse waren sehr konsistent, was die Verlässlichkeit dieser Studie bestätigt.

## Notes

### Acknowledgements

Much of the work presented in this paper was supported by the National Basic Research Program of China (973 Program, Grant 2013CB036002), the National Natural Science Foundation of China (Grant 51509147), and the promotive research fund for excellent young and middle-aged scientists of Shandong Province (Grant BS2014NJ004). The authors thank the reviewers for their valuable comments and suggestions that helped improve the quality of the paper.

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