Strong Mining-Induced Seismicity Characteristics and Precursor Signals Based on Statistical Seismology

As a consequence of the ongoing expansion of coal mining operations in China, the geological conditions encountered in these operations have become increasingly complex. Mining-induced seismicity is a frequent occurrence, resulting in significant economic losses. A total of 12,000+ mining-induced seismic events have been recorded during deep coal mining in the Ordos Mining Area. This study examines the distribution pattern of mining-induced seismicity and analyzes the aftershock attenuation and seismic migration patterns of mining-induced seismic events based on typical mining-induced seismic sequences. The findings demonstrate that the modified Omori law offers a clear description of the decay pattern of aftershocks triggered by strong mining-induced seismicity. Over time, the magnitude and frequency of the aftershocks exhibit a decay pattern consistent with a t-p law. The power law GR relationship is applicable to the mining-induced seismic sequence. In advance of a strong mining-induced seismicity, the b-value will decline below the norm (1.0-1.1) and the number of microseisms will rise markedly, indicating the commencement of the nucleation phase. Such signals may be regarded as an indicator of an impending strong mining-induced seismicity. The seismic migration rate in the Ordos Mining Area, which is influenced by the geological environment, has been observed to be relatively stable at approximately 65 m/day. The mining-induced seismic migration and diffusion laws provide a theoretical explanation for the phenomenon of coordinated fracture of overlying key strata.