Experimental Investigation of Sensitivity for Coal and Gas Outburst Risk Prediction Indexes in Raw and Tectonic Composite Coal Seams

ABSTRACT The prediction of coal and gas outburst risk is a critical first step in preventing and controlling gas‐related accidents. To evaluate the sensitivity of outburst risk prediction indexes in raw and tectonic composite coal seams, both regional and local indexes for the No. 3 coal seam in the Daning Coal Mine were analyzed. Results indicate that tectonic coal exhibits higher initial gas desorption capacity and faster desorption rates than those of raw coal, resulting in a greater risk of coal and gas outbursts in tectonic coal seams. Among the regional outburst risk prediction indexes for the raw and tectonic composite coal seams, gas content was found to be more sensitive than gas pressure. A gas content of 8.00 m 3 /ton is identified as a safer critical threshold for the No. 3 coal seam. For local outburst risk prediction indexes, a comparison of gas desorption characteristics and index values under consistent laboratory‐determined pressure conditions reveals that the drilling cuttings gas desorption index K 1 exhibits lower determination error and higher sensitivity than Δ h 2 , enabling more accurate prediction of coal and gas outburst risk. Furthermore, a K 1 value of 0.46 mL/(g·min 0.5 ) is identified as a safer critical threshold for the No. 3 coal seam. These findings provide a crucial theoretical foundation for guiding the prevention and control of coal and gas outbursts and can inform process engineering design and coal mine safety practices.