Improved Grey Correlative Method for Risk Assessment on Coal and Gas Outburst

The improved grey correlative model was put forward in order to improve the objectivity of grey synthetic evaluation method. Balanced degree was ascertained by entropy theory. Weighted grey correlative degree was synthesized by grey correlative coefficient and entropy weights. Balanced adjacent degree, which was derived from weighted grey correlative degree and balanced degree, was taken as the evaluation criteria in the improved model. Therefore, grey synthetic evaluation result is more reasonable. The model has been applied in the safety assessment of coal and gas outburst for four mining faces from east area of Ping Dingshan mining area. The risk differences among four faces were attained. At the same time, corresponding countermeasures to prevent outburst are put forward. The evaluation results indicate that the improved method be more reasonable and objective than general grey correlative method.