Research on the occurrence mechanism of mine earthquake in Longwanggou Coal Mine and its damage assessment to surface buildings

The mining of extra-thick coal seams is prone to triggering mine earthquake, which causes damage to surface buildings and severely restricts the sustainable development of coal mines. This study constructs a spatial structural model of hard rock tearing-type fracture at the 61,607 working face in Longwanggou Coal Mine. Through analytical modeling of stress-energy characteristics during fracture propagation, we quantitatively estimate the vibrational energy partitioning within rock mass discontinuities and evaluate the maximum potential magnitude (ML) of mine earthquake. Critical kinematic parameters, including peak ground acceleration (PGA) and particle velocity (PGV), are extracted to systematically evaluate vibration-induced damage to surface structures, with data sourced from seismic waveforms. The results indicate that the maximum magnitude estimated by the calculation model for hard rock tearing-type mine earthquake is in close agreement with on-site monitoring results, exhibiting a deviation of approximately 14%. The peak values of the acceleration response spectrum for seismic signals are concentrated in the 0.1-0.5 s range, where the bottom frames of buildings with natural vibration periods close to this interval are affected to a certain extent but exhibit lower vibration intensity than that induced by natural earthquakes. The attenuation of mine earthquake vibrations adheres to a power-law exponential pattern, with PGA decaying to an extremely low level at kilometer-scale distances. Additionally, the velocity response of mine dormitories meets relevant safety standards, collectively indicating that mine earthquake exerts essentially no substantial impact on the structural integrity of surface buildings.