## 6 Dynamic Regulation Evaluation Methodology for Strata Pressure Manifestations  
Microseismic events are phenomena characterized by the release of elastic waves resulting from localized fracturing due to stress imbalance within rock masses. Their intrinsic nature reflects the dynamic process of energy accumulation and release in coal-rock masses under mining-induced disturbances [24]. Microseismic monitoring evaluates rock mass stability by detecting elastic waves generated by internal microfractures. Through real-time acquisition of elastic wave signals triggered by microfractures, microseismic monitoring systems quantitatively characterize the spatiotemporal evolution of mining-induced stress fields. Microseismic events arise from the coupled effects of mining-induced stress redistribution, overburden deformation, and caving [25]. Given the real-time capability of microseismic monitoring, utilizing multidimensional parameters (event frequency, energy release rate) as the primary basis for face advancing rate adjustment demonstrates scientific validity and technical rationality. Microseismic daily energy and event frequency serve as primary indicators for dynamic regulation. By analyzing their temporal variations, anomalies during advancement  
Figure 21: Correlation between face advancing rate and daily total microseismic energy at Panel 12308. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Stage Name** & **Advance Rate** & **Advance Rate** & **Microseismic Event** & **Total Energy of** & \\
**Range/(m\(\cdot\)d\({}^{-1}\))** & **Rate/(m\(\cdot\)d\({}^{-1}\))** & **Count/(Times\(\cdot\)d\({}^{-1}\))** & **Microseismic Events/(J\(\cdot\)d\({}^{-1}\))** & **Emax/J** \\ \hline Low-speed & 2–4 & 3.7 & 1.4 & 9.4 \(\times\) 10\({}^{3}\) & 7.7 \(\times\) 10\({}^{3}\) \\ mining phase & 8–10 & 8.4 & 3.4 & 2.2 \(\times\) 10\({}^{4}\) & 7.9 \(\times\) 10\({}^{3}\) \\ mining stage & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Relationships between microseismic events and mining advance rates. can be identified. For granular phase-specific analysis, mining operations were categorized as follows:  
1. Low-speed phase: Cumulative advancement = 126 m;
2. High-speed steady phase: Cumulative advancement = 742 m;
3. High-speed unsteady phase: Cumulative advancement = 508 m (total high-speed advancement = 1250 m). Microseismic energy data were statistically analyzed using 10 kJ/d intervals to calculate the percentage distribution across energy ranges, as shown in Figure 22. The results indicate that during the low-speed advancing phase and high-speed steady advancing phase, microseismic energy predominantly fell within the 0-20 kJ/d range, exhibiting regular distribution patterns dominated by low-energy, high-frequency events. In contrast, the high-speed unsteady advancing phase displayed microseismic energy concentrated in the 10-20 kJ/d (20.9%), 30-40 kJ/d (19.4%), and >50 kJ/d (20.9%) ranges, demonstrating significant energy dispersion and fluctuation. Cumulative statistics of microseismic energy intervals (10 kJ/d increments) are presented in Figure 23. The cumulative energy distribution for the low-speed and high-speed steady phases followed an approximate curvilinear trend, while the high-speed unsteady phase exhibited an approximate linear cumulative increase. Cumulative energy analysis using 10 kJ/d intervals (Figure 22) reveals the following: (1) Low-speed and high-speed steady phases: Cumulative energy follows a near-curvilinear ascending trend. (2) High-speed unsteady phase: Cumulative energy exhibits a near-linear ascending pattern. Based on Figure 23, 40 kJ/d is established as the critical threshold for the low-speed phase, serving as a microseismic energy-based production-limiting criterion. Due to the absence of a valid threshold in the unsteady phase, 50 kJ/d from the high-speed steady phase  
Figure 23: Cumulative microseismic energy intervals under different advance rates. (**a**) Low-speed phase; (**b**) high-speed steady phase; (**c**) high-speed unsteady phase.