Frequency Response of Acoustic Emission to Characterize Particle Dislocations in Sandy Soil

The understanding of internal response of particle dislocations is vital to clarify the progressive failure in granular materials. This paper proposes a non-destructive testing method, Acoustic Emission (AE) technology, to characterize the mechanical behavior associated with particle-to-particle sliding and asperity/particle breakage in sand subjected to drained-triaxial compression. Particle dislocations during compression is accompanied by a sudden release of stored strain energy, which could be detected by AE sensors and characterized as elastic waves with different frequency properties. Insights into the correlations of stress-strain and frequency response of AE activities in terms of total, high frequency and low frequency AE event rates are offered, demonstrating that the mechanical behavior of particle dislocations and soil density could be highly characterized by AE activities. Besides, particle dislocations associated with particle-to-particle sliding and asperity/particle breakage is distinguished by high frequency and low frequency AE activities. The result suggested that the frequency response of AE activities is closely related to the failure mode, degree and rate of sand particle dislocations under drained triaxial compression. This technology seems promising as an alternative means to clarify the inter-particle mechanism during progressive failure in sand.