ReviewPerformance analysis of piezoceramic elements in soil: A review

- Aspect ratio of the bender/extender elements governs its usefulness in various laboratory soil testing.
- Electro-magnetic coupling effects can be controlled by adopting a suitable wavelength ratio.
- Different sets of frequency and amplitude are assigned in different soils to get clear waveforms.
- Specimen aspect ratio of 2 is found to be ideal in minimizing boundary wall effect.

Piezoceramic elements are the electro-mechanical transducers which generate shear and compression waves. Application of these piezoceramic bender/extender elements is an emerging trend in geotechnical engineering for determining various soil properties. However, wave velocities using piezoceramic elements are influenced by various factors such as the bender-soil interaction, types of input waves, particle size and shape, dimension of soil specimen, contact behaviour, reflection and refraction phenomena and various circuitry parameters such as frequency, amplitude, electro-mechanical properties and geometry of bender/extender elements. Keeping this in view, a detailed review and analysis of the results from bender/extender element testing as available in literature was done and is presented in this paper. Analysis of the test results available in literature has been done with reference to various factors influencing wave velocity and the method of interpretation. Outcome from the present work is supposed to be very useful for selection of various measuring parameters during bender/extender tests in soils.