Particle velocity generated by rockburst during exploitation of the longwall and its impact on the workings

As a consequence of geomechanical and geotechnical conditions and also anthropogenic activities in mines of the Ostrava-Karviná Coal Basin (Czech Republic) rockbursts have been recognized to be a serious seismic risk. Therefore, local as well as regional monitoring arrays were deployed there in order to investigate the actual seismic activity continually. One of the essential parameters which was observed at the seismic stations situated in-situ was the particle velocity of P- and S-waves. The aim of this paper is to derive some empirical dependences by determining the decrease of seismic wave amplitudes with distance from rockburst foci. Seismic energy, local magnitude, co-ordinates of seismic stations, rockburst foci and positions where damage to workings occurred were employed as additional imput. Moreover, the degree of this damage was tested based on the values of particle velocity and, simultaneously, stress due to the loading of the workings by the stress wave was also calculated.

► We continuously monitor mining-induced seismicity in hard coal mines.
► The particle velocity is recorded using three 3-axial sensors underground.
► We calculate the decay factor for P- and S- waves after introducing the square root scaling.
► Lengths of the working devastations is compared either with particle velocity or with calculated acting stress.