Fault quasi-static and dynamic ruptures in deep coal mining: impacts on working faces

Abstract

This study analyzes static and dynamic ruptures in deep coal mining and their impacts on working faces. Using a 2-D numerical model with PyLith, we evaluate the energy, stress disturbances, and seismic wave effects induced by a nearby reverse fault. By pioneering PyLith in induced seismicity research, we provide critical insights into the interactions between mining operations and geological structures. The model simulates fault slip processes and their effects on the working face, focusing on stress changes, energy concentration, peak particle velocity (PPV), and peak particle acceleration (PPA) under varying conditions of mining-induced seismicity. Static deformation due to fault slip caused significant stress changes on both the ceiling and floor of the working face, with stress values ranging from 0.9 MPa to 39 MPa in σ_xx, 0.6 MPa to 14.7 MPa in σ_xy, and 1.1 MPa to 22 MPa in σ_yy. Energy concentration was observed at the corners of the working face near the fault. Dynamic analysis revealed rupture durations ranging from 250 ms to 670 ms, with rupture velocities decreasing from 1.25 km/s to 0.62 km/s as the characteristic slip distance (D_c) increased. Seismic waves showed that both PPV and PPA decreased with increasing D_c. Our findings highlight the necessity of advanced numerical modeling to predict and manage hazards associated with mining-induced seismic events. Additionally, the study emphasizes the importance of designing robust support systems and implementing safety measures to ensure the stability and safety of mining operations under seismic conditions.