Directional Attenuation Relationship for Ground Vibrations Induced by Mine Tremors

The paper presents the discussion on problems involving the reproduction of the acceleration field of ground vibrations based on the pointwise registration carried out in coal mines subjected to seismic hazard. Simple model that takes into account directional effects of seismic wave attenuation has been presented. It has been accepted the assumption that the contours of the peak ground accelerations take the shape of an ellipse. The carried out calculations for three cases of very strong ground vibrations caused by mine tremors which occurred in three regions of coal mines, show that the application of the proposed model allows us to reduce the value of standard error of the estimate as compared to the results obtained with the commonly applied regression model, which does not allow for the directional effects of attenuation. For the investigated regions, it was showed, that the directional effects of the attenuation depends on the directions of the nearest big tectonic faults.