Particle soil crushing: passive detection and interpretation

Soil grain crushing has a significant influence on the performance of the geotechnical systems. However, the mechanics
of particle breakage remains one of the most difficult problems in geomechanics. For a bulk of soil grains under loading, one of the
ongoing challenges is the prediction of the extent of soil particle crushing and its evolution. While the main goal of a wider research is
to investigate the possibility of using Acoustic Emission (AE) technique to characterise the extent and evolution of soil grain
crushing, this paper particularly focuses on individual grains under uniaxial compression loading. Insight into the use of AE to
characterize the crushing mechanism and signature is gained through testing of individual particles of chalk. For one particle, it
appears that the frequency content of the AE recorded signals does not seem to be affected by a particular crushing mechanism,
limited fragmentation or critical failure. However, the discrimination between these two mechanisms is given through inspection of
the corresponding waveforms and evaluation of parameters like maximum amplitude and energy. Similar size particles also appear to
provide good repeatability with similar frequency contents for both crushing mechanisms.