Deterministic cascade evolution in coal and gas outbursts: From early acoustic signatures to system-wide failure
Yang Lei, Zhijie Wen, Liang Wang, Ting Ren, Yujun Zuo
Abstract
Coal and gas outbursts constitute a critical hazard in underground mining operations, characterized by rapid transitions from localized instability to catastrophic failure. Understanding the relationship between initial characteristics and final outburst scale remains a fundamental challenge in geomechanics. This study conceptualizes outbursts as deterministic cascade systems through integrated physical simulations combining high-sensitivity infrasound monitoring with energy analysis under controlled gas pressure (0.5–1.0 MPa) and confining stress (5–10 MPa) conditions. Our complementary analytical algorithms—the absolute amplitude integral and predominant period function—revealed characteristic step-wise patterns in outburst development. Quantitative analysis established a robust correlation ( R 2 =0.91) between initial acoustic response and final outburst intensity. Energy analysis demonstrated that gas expansion dominates the outburst process (91.81%–99.09% of total energy), with desorption gas contributing 59.1%–77.7%. Time-frequency analysis showed systematic frequency migration from high (12–15 Hz) to low (4–8 Hz) bands during outburst progression, reflecting hierarchical spatial scale expansion. The concentrated energy release (>20% of total) within initial 0.2 s provides a mechanistic basis for the deterministic nature of outburst evolution. These mechanistic insights establish a quantitative framework for developing physics-based monitoring protocols and risk assessment methodologies applicable to underground coal mining operations.