Penetration Type Field Velocity Probe for Soft Soils
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 136, Issue 1
Abstract
The assessment of the shear stiffness of dredged soft ground and soft clay is extremely difficult due to soil disturbances caused during sampling and field access. Several in situ methods such as spectral analysis of surface waves, multichannel analysis of surface wave, cross hole, and downhole methods have been developed to measure the shear-wave velocity, but a few disadvantages hinder the adoption of existing methods to soft ground. This study presents a new apparatus, the penetration type field velocity probe (FVP), which overcomes several of the limitations of commonly used shear-wave measurement methods in the field. Design concerns of the FVP include the tip shape, soil disturbance, transducers, self acoustic insulation, protectors, and the electromagnetic coupling from transducer-to-transducer and cable-to-cable. The crosstalk between cables is eliminated by grouping and extra grounding of the cables. The shear-wave velocity of the FVP is directly calculated, without any inversion process, by using the travel distance and the travel time. After calibration tests are carried out in the laboratory, application tests in the field are conducted up to 29 m in depth. Calibration results show the velocity profiles obtained by the FVP and by the rods fitted with transducers are similar to each other. The experimental results obtained in the field show that the FVP can produce reasonable and detailed shear-wave velocity profiles in soft clay. This study suggests that the FVP may be an effective technique for measuring the shear-wave velocity in soft ground.
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Acknowledgments
This work was supported by Korea Research Foundation Grant funded by the Korean Government (MOEHRD, Basic Research Promotion Fund, Grant No. UNSPECIFIEDKRF-2006-311-D00218). The experimental tests were conducted at Busan New Port North Container Terminal Project (Main contractor: Samsung Corporation). Anonymous reviewers provided insightful comments and suggestions.
References
Aki, K., and Richards, P. G. (2002). Quantitative seismology, 2nd Ed., University Science, Sausalito, Calif., 700.
ASTM. (2006). “Standard test methods for crosshole seismic testing.” Annual book of ASTM standard, D4428-00, Vol. 04.08, West Conshohocken, Pa.
ASTM. (2007). “Standard test methods for downhole seismic testing.” Annual book of ASTM standard, D7400, Vol. 04.09, West Conshohocken, Pa.
Bartake, P. P., and Singh, D. N. (2007). “Studies on the determination of shear wave velocity in sands.” Geomech. Geoeng., 2(1), 41–49.
Dyvik, R., and Madshus, C. (1985). “Lab measurements of using bender elements.” Proc. ASCE Convention on Advances in the Art of Testing Soils under Cyclic Conditions, ASCE, New York, 186–196.
Ishihara, K. (1996). Soil behaviour in earthquake geotechnics, Oxford Science, England.
Jo, C. H., Byun, J., and Hwang, S. (2006). “Considerations on the difficulties in velocity logging in the near surface environments.” Mulli-Tamsa, 9(3), 185–192.
Larkin, T. J., and Taylor, P. W. (1979). “Comparison of down-hole and laboratory shear wave velocities.” Can. Geotech. J., 16, 152–162.
Lee, C., Lee, J. S., Lee, W., and Cho, T. H. (2008). “Experiment setup for shear wave and electrical resistance measurements in an oedometer.” Geotech. Test. J., 31(2), 149–156.
Lee, J. S., and Santamarina, J. C. (2005). “Bender elements: Performance and signal interpretation.” J. Geotech. Geoenviron. Eng., 131(9), 1063–1070.
Locat, J., and Tanaka, H. (1999). “Microstructure, mineralogy and physical properties: techniques and application to the Pusan clays.” Proc., Korean Geotechnical Society (KGS) ’99 Dredging and Geoenvironmental Conf., KGS, Seoul, Korea, 15–31.
Luke, B. A., and Stokoe, K. H., II. (1998). “Application of SASW method underwater.” J. Geotech. Geoenviron. Eng., 124(6), 523–531.
Owen, W. P., and Roblee, C. J. (2000). “Borehole velocity logging for Caltrans’ earthquake engineering program: comparison of field measurement.” Proc., Geophysics 2000, Federal Highway Administration and Missouri Dept. of Transportation, St. Louis.
Paoletti, L., Mouton, E., and Maraschini, W. (2006). “Underwater application of spectral analysis of surface waves.” Proc., GeoCongress2006: Geotechnical Engineering in the Information Technology Age, ASCE, Atlanta.
Stokoe, K. H., II, and Santamarina, J. C. (2000). “Seismic-wave-based testing in geotechnical engineering.” Proc., Int. Conf. on Geotechnical and Geological Engineering, Melbourne, Australia, 1490–1536.
Stokoe, K. H., II, Wright, S. G., Bay, J. A., and Rosset, J. M. (1994). “Characterization of geotechnical sites by SASW method.” Geophysical characterization of sites, R. D. Woods, ed., Oxford, New Delhi.
Viggiani, G., and Atkinson, J. H. (1995). “Interpretation of bender element tests.” Geotechnique, 45(1), 149–154.
Zeng, X. (2006). “Applications of piezoelectric sensors in geotechnical engineering.” Smart Structures and Systems, 2(3), 237–251.
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Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 136 • Issue 1 • January 2010
Pages: 199 - 206
Copyright
© 2010 ASCE.
History
Received: Oct 20, 2006
Accepted: Apr 7, 2009
Published online: Dec 15, 2009
Published in print: Jan 2010
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