Analysis of spatial and temporal distribution laws of mine earthquake induced by thrust fault coal bumps under mining disturbance

In order to analyze the spatial and temporal distribution laws of mine earthquake induced by thrust fault coal-bump under mining disturbance, according to the power distribution law of G-R seismic activity, combined with the in-situ monitoring micro-seismic data and numerical simulation method, the frequency and energy release levels of high-magnitude events in underground mine earthquake activities are analyzed by b value and seismic moment M0.The results show that:the distribution law of underground micro-seismic activity is similar to the seismic distribution law of the crust.The activity of micro-seismic events is related to the b value.The smaller the b-value is, the higher the frequency of high-magnitude mine shock event in the entire mine shock events, and the more serious the impact on the working face.The analysis finds that the b value is affected by the in-situ stress, mining disturbance, and fault properties.Specifically:increasing the maximum and minimum principal stress difference, mining rate, fault throw or decreasing fault dip angle will reduce b value, resulting in high activity of micro-seismic activity, inducing coal-bump, and threatening the safe mining.There is obvious difference in the spatial distribution of thrust fault seismic moment M0.Under the influence of mining disturbance, the seismic moment in the upper area of the fault is relatively large.As the working face is approached, the overall value of the seismic moment is continuously increasing, and the area of high peak seismic moment is continuously expanding from top to bottom.The increase of the seismic moment value on the fault means that the level of releasable energy continues to increase, and the corresponding disturbance to the working face will be more intense, further increasing the risk of coal bumps.