Theoretical method and technology of precision identification for coal and gas outburst hazard

There are many practical problems for coal and gas outburst in China,such as the frequent occurrence,the new features which has emerged,and the prediction method and index system which need to be improved. In order to better guide the prediction and prevention of coal and gas outburst,the theoretical method of “ Layers of progressive- Precision identification” for coal and gas outburst hazard is proposed,which includes three levels,under the guidance of key structural body theory of coal and gas outburst,and based on the basic understanding that the outburst location must have the special geological structure environment. The abnormal geological structure around the mining face is detected in advance by the method of geophysical prospecting and drilling. Based on the real-time monitoring of micro- seism and gas emission,the change of coal structure,crustal stress and gas in front of the mining face are dynamically analyzed under the condition of mining disturbance. The identification results of the advanced detection and real-time monitoring are further verified by the measured relevant feature parameters and prediction indexes of coal and gas out- burst while drilling. Exploratory engineering tests show that the identification method of outburst hazard,which includes “Advanced detection of abnormal geological structure-real-time monitoring of coal and gas outburst hazard-Measure- ment of coal seam gas while drilling”,can comprehensively indicate the geological structure,coal structure,crustal stress and gas around the mining face,which promotes the transformation of coal and gas outburst prediction from point prediction to face prediction,from discontinuous prediction to continuous prediction,and from contact prediction to contact and non-contact combined prediction. The fine detection technology which includes geophysical prospecting and drilling needs further development. Big data analysis and machine learning algorithm are introduced to train com- prehensive judgment model. A comprehensive early-warning system is developed with the core of “Advanced detection of abnormal geological structure-real-time monitoring of micro-seismic signal and time series of gas emission in mining face-Measurement of various feature parameters and prediction indexes while drilling”. It is expected to realize com- prehensive monitoring of multivariate information and intelligent early warning for outburst hazard,which will better serve the prevention and control of coal and gas outburst.