Selecting an Appropriate Shear Plate Configuration to Measure Elastic Wave Velocities
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- Masahide Otsubo
- Institute of Industrial Science, The University of Tokyo 1 , 4-6-1 Komaba, Meguro-ku, Tokyo153-8505, Japan (Corresponding author), e-mail: otsubo@iis.u-tokyo.ac.jp , ORCID link for author moved to before name tags https://orcid.org/0000-0001-6738-2160
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- Catherine O’Sullivan
- Department of Civil and Environmental Engineering, Imperial College London 2 , Skempton Building, South Kensington Campus, Exhibition Rd., LondonSW7 2AZ, United Kingdom of Great Britain and Northern Ireland
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- Steven Ackerley
- Department of Civil and Environmental Engineering, Imperial College London 2 , Skempton Building, South Kensington Campus, Exhibition Rd., LondonSW7 2AZ, United Kingdom of Great Britain and Northern Ireland
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- Duncan Parker
- Department of Physics, Imperial College London 3 , Blackett Laboratory, South Kensington Campus, Prince Consort Rd., LondonSW7 2BW, United Kingdom of Great Britain and Northern Ireland
説明
<jats:title>Abstract</jats:title> <jats:p>The (small-strain) elastic moduli of soil can be determined from stress wave velocity measurements. Bender/extender elements are widely used in laboratory experiments; however, discussion on how to accurately determine wave velocities using this method continues. Planar piezoelectric transducers (sometimes called shear plates) are a relatively new technology, whose use is not yet widely established, that appear to offer some advantages in comparison with bender/extender elements for laboratory geophysics tests. This contribution critically assesses the use of planar piezoelectric elements experimentally and using discrete element method (DEM) simulations. Planar piezoelectric elements capable of generating and receiving either shear or compression waves were placed in the top and base caps of a triaxial apparatus. Samples of glass ballotini were used so that stress wave propagation simulations could be performed on equivalent virtual samples using DEM. The appropriate shear plate configuration to effectively measure the shear wave velocity is explored. Considering both time- and frequency-domain responses, it is revealed that shear plate signals are sensitive to the surface area and thickness of the piezoelectric elements and to the lateral boundary conditions. Using a shear plate with the widest possible surface area exposed to the soil specimen is recommended to increase the signal-to-noise ratio and to produce more planar shear waves, resulting in a more accurate measurement of shear wave velocity.</jats:p>
収録刊行物
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- Geotechnical Testing Journal
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Geotechnical Testing Journal 43 (6), 1519-1540, 2020-11-01
ASTM International