Acoustic Emission in a Layer of Geomaterial under Deformation by Shear

Resumo

The new method is proposed for interpreting data of acoustic emission during initiation and growth of dynamic breakaways. The method is based on the analysis of wave form of the emitted acoustic pulses. Clustering of the pulses by the wave form criterion shows that in the localization zone of strains different-scale processes described with various scaling relations take place. All classes of acoustic pulses obey the power-series amplitude-frequency distribution. The sharp-arrival acoustic pulses posses unaltered scaling relations in the period of nucleation and growth of dynamic breakaways whereas the smooth-arrival pulses demonstrate the nonlinear change in the scaling relations. At the final stage of the dynamic breakaway formation, the proportion and amplitude of acoustic pulses with smooth arrival increase.