Determination of critical thresholds for sensitive indicators in coal and gas outburst prediction for deep complex...

Coal and gas outburst represents a highly destructive dynamic phenomenon inherent in deep coal mining operations. Currently, outburst prediction frameworks rely heavily on a uniform critical threshold system recommended by national regulations. However, within heterogeneous coal seams characterized by complex geological conditions, this universal approach frequently leads to "low-index outburst" incidents or excessive engineering redundancy, significantly undermining the intrinsic safety of mine operations. To address this core scientific bottleneck, the present study establishes a theoretical methodology for the quantitative determination of sensitive prediction indicators and proposes a hierarchical optimization framework for both regional and local critical thresholds. By integrating long-term historical statistics, laboratory kinetic tests of gas desorption, and in-situ multi-point tracking and verification, the critical thresholds undergo scientific calibration and site-specific alignment. Empirical research conducted on the No. 1 coal seam of the Miluo Coal Mine in Guizhou demonstrates that, at the regional prediction level, gas content and gas pressure exhibit equivalent sensitivity, with established critical values of 8.0 m³/t and 0.74 MPa, respectively. Furthermore, the sensitivity hierarchy for local prediction indicators was determined as [Formula: see text]. Significantly, the finalized local thresholds ([Formula: see text]= 0.47 mL/(g·min^0.5), [Formula: see text]= 184 Pa, and S= 6.0 kg/m) are more stringent than the recommendations set forth in the Detailed Rules for Prevention and Control of Coal and Gas Outburst. The proposed prediction system effectively standardizes disaster characterization in complex coal seams and provides strategic guidance for coal mining enterprises to establish precision-based, site-specific outburst prevention standards. Coal and gas outbursts constitute a highly destructive dynamic phenomenon inherent in deep coal mining operations. Current outburst prediction frameworks largely depend on a uniform critical threshold system mandated by national regulations. However, in heterogeneous coal seams characterized by complex geological conditions, this universal approach frequently leads to "low-index outburst" incidents or excessive engineering redundancy, significantly undermining the intrinsic safety of mining operations. To resolve this fundamental scientific bottleneck, the present study establishes a theoretical methodology for the quantitative determination of sensitive prediction indicators and proposes a hierarchical optimization framework for both regional and local critical thresholds. By integrating long-term historical statistics, laboratory kinetic tests of gas desorption, and in-situ multi-point tracking and verification, the critical thresholds undergo rigorous scientific calibration and site-specific alignment. Empirical research conducted on the No. 1 coal seam of the Miluo Coal Mine in Guizhou demonstrates that, at the regional prediction level, gas content (w) and gas pressure (p) exhibit equivalent sensitivity, with established critical values of 8.0 m³/t and 0.74 MPa, respectively. Furthermore, the sensitivity hierarchy for local prediction indicators was established as [Formula: see text]. Significantly, the finalized local thresholds ([Formula: see text]= 0.47 mL/(g·min^0.5), [Formula: see text]= 184 Pa, and S= 6.0 kg/m) are more stringent than the standards set forth in the Detailed Rules for Prevention and Control of Coal and Gas Outburst. The proposed prediction system effectively standardizes hazard characterization in complex coal seams and provides strategic guidance for coal mining enterprises to establish precision-based, site-specific outburst prevention standards.