Numerical and Field Investigations of Dynamic Failure Caused by Mining-Induced Tremor Based on Asymmetry Seismic Source Characteristics

The asymmetry of seismic rupture significantly dictates the intensity and spatial distribution of the radiated stress waves during mining-induced tremors, exerting a pivotal influence on the dynamic instability of roadways triggered by mining-induced tremors. In this study, a method for simulating arbitrary rupture patterns based on the theory of moment tensors is proposed. Based on the engineering context of strong seismicity-induced roadway dynamic instability at the Xinjulong coal mine, the entire process, from the excitation and propagation of seismic stress waves to the subsequent destabilization and destruction of the roadway, is reproduced. The effects of seismic source, including rupture patterns, seismic energy, fault plane angles, and the dominant frequency of stress waves, on the stability of a roadway are analyzed. Research indicates that a strong mining-induced tremor is characterized by tensile failure, with the radiated P-waves playing a predominant role in the destabilization and collapse of the roadway compared to S-waves. The P-waves exert a repetitive tensile and compressive effect on the perturbed medium, whereas S-waves contribute through compressive shear actions. The stability of a roadway is influenced by various characteristics of the seismic source. The rupture pattern of the seismic source affects the spatial distribution of stress waves. The seismic energy influences the kinetic energy transmitted to the roadway, with an increase in energy leading to a greater contribution of S-waves to roadway destruction. The fault plane angle similarly affects the propagation pattern of stress waves, particularly at 45° and 60° angles, where the maximum radiation of P-waves is directed towards the roadway, causing the most severe damage. The dominant frequency affects the attenuation of stress waves, with lower frequencies resulting in less attenuation and a higher likelihood of roadway damage.