Evaluation of Remolded Shear Strength and Sensitivity of Soft Clay Using Full-Flow Penetrometers
This article has a reply.
VIEW THE REPLYThis article has a reply.
VIEW THE REPLYPublication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 135, Issue 9
Abstract
The undrained remolded shear strength of soft clays is of importance in geosystem design, particularly for offshore structures. Common methods to estimate remolded shear strength, such as correlations with cone penetration data, direct measurement with an in situ field vane shear device, and laboratory measurements, produce varied results and can be particularly costly and time consuming. Full-flow penetrometers (T-bar and Ball) provide an alternative rapid method to estimate remolded shear strength and soil sensitivity through remolding soil by repeated cycling of the penetrometer up and down over a given depth interval. The cyclic penetration resistance degradation curve inherently contains information regarding remolded strength and sensitivity. The objective of this paper is to assess the ability of full-flow penetrometers to predict remolded strength and soil sensitivity, and to develop a suite of predictive correlations in which these properties can be estimated in the absence of complementary laboratory or in situ test data. To accomplish this, full-flow penetration profiles and cyclic tests were performed at five well characterized soft clay sites, which together represent the broad range of soils in which the penetrometers will be often used. A previously developed model for the reduction in penetration resistance with cycling is modified to predict the entire degradation curve, including the remolded penetration resistance using only measurements obtained during initial penetrometer penetration and extraction. Using field vane shear strength as the reference measurement, correlations are developed to predict soil sensitivity and remolded shear strength based solely on full-flow penetrometer data, which is particularly useful in site investigation programs where site specific data are not yet available or are sparse. Finally, the usefulness of these relationships is demonstrated by implementing them for two additional soft clay sites.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
Funding from the National Science Foundation (Grant Nos. NSFCMS 0301448 and NSFOISE 0530151) is appreciated. Data from the Bothkennar site were provided by Professor Michael Long (University College Dublin) and his colleague Noel Boylan and is much appreciated.
References
ASTM. (2000). “Standard test method for performing electronic friction cone and piezocone penetration testing of soils.” ASTM D 5778-95, West Conshohoken, Pa.
ASTM. (2003a). “Standard test method for laboratory miniature vane shear test for saturated fine-grained clayey soil.” ASTM D 4648-00, West Conshohoken, Pa.
ASTM. (2003b). “Standard test method for field vane shear test in cohesive soil.” ASTM D2573-01, West Conshohoken, Pa.
Bonaparte, R., and Mitchell, J. K. (1979). “The properties of San Francisco Bay mud at Hamilton Air Force Base.” Rep. Prepared for the Dept. of Civil Engineering, Univ. of California, Berkeley, Berkeley, Calif.
Boylan, N., Long, M., Ward, D., Barwise, A., and Georgious, B. (2007). “Full-flow penetrometer testing in Bothkennar clay.” Proc., 6th Int. Offshore Site Investigation and Geotechnics Conf., Society for Underwater Technology, London, 177–186.
Chung, S. F. (2005). “Characterisation of soft soils for deep water developments.” Ph.D. thesis, Dept. of Civil and Resource Engineering, The Univ. of Western Australia, Nedlands, Western Australia, Australia.
DeGroot, D. J., DeJong, J. T., Yafrate, N. J., Landon, M. L., and Sheahan, T. C. (2007). “Application of recent developments in terrestrial soft sediment characterization methods to offshore environments.” Proc., OTC-07: Offshore Technology Conf., Curran Associates, Red Hook, N.J.
DeGroot, D. J., and Lutenegger, A. J. (2003). “Geology and engineering properties of Connecticut Valley carved clay.” Characterization and engineering properties of natural soils, T. S. Tan, K. K. Phoon, D. W. Hight, and S. Lerouell, eds., Vol. 1, Balkema, Rotterdam, The Netherlands, 695–724.
DeJong, J. T., Yafrate, N. J., and Randolph, M. F. (2008). “Use of pore pressure measurements in a ball full-flow penetrometer.” Geotechnical and geophysical site characterization (ISC-3), Taylor and Francis, Taipei, Taiwan, 1269–1275.
Einav, I., and Randolph, M. F. (2005). “Combining upper bound and strain path method for evaluating penetration resistance.” Int. J. Numer. Methods Eng., 63(14), 1991–2016.
International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE). (1999). “International reference test procedure for the cone penetration test (CPT) and the cone penetration test with pore pressure (CPTU).” Rep.
Kelleher, P. J., and Randolph, M. F. (2005). “Seabed geotechnical characterisation with the portable remotely operated drill.” Proc. Int. Symp. on Frontiers in Offshore Geotechnics (ISFOG), Taylor and Francis, Rotterdam, The Netherlands, 365–371.
Ladd, C. C. (1991). “22nd Karl Terzaghi lecture: Stability evaluation during staged construction.” J. Geotech. Engrg., 117(4), 540–615.
Leroueil, S., Hamouche, K., Ravenasi, F., Boudali, M., Locat, J., and Virely, D. (2003). “Geotechnical characterization and properties of a sensitive clay from Quebec.” Characterization and engineering properties of natural soils, T. S. Tan, K. K. Phoon, D. W. Hight, and S. Lerouell, eds., Vol. 1, Balkema, Rotterdam, The Netherlands, 363–394.
Lo, K. Y., Bozozuk, M., and Law, K. T. (1976). “Settlement analysis of the Gloucester test fill.” Can. Geotech. J., 13(4), 339–354.
Long, M. (2008). “Design parameters from in situ tests in soft ground-recent developments.” Proc., ISC-3: 3rd Int. Conf. on Site Characterization, H. Mayne, ed., Taylor and Francis, Taipei, Taiwan.
Lu, Q., Hu, Y., and Randolph, M. F. (2000). “FE analysis for T-bar and spherical penetrometers in cohesive soil.” 10th Int. Offshore and Polar Engineering Conf., 617–623.
Lunne, T., Long, M., and Forsber, C. F. (2003). “Characterization and engineering properties of Onsøy clay.” Characterization and engineering properties of natural soils, T. S. Tan, K. K. Phoon, D. W. Hight, and S. Lerouell, eds., Vol. 1, Balkema, Rotterdam, The Netherlands, 395–427.
Lunne, T., Randolph, M. F., Chung, S. F., Andersen, K. H., and Sjursen, M. (2005). “Comparison of cone and T-bar factors in two onshore and one offshore clay sediments.” Proc., Int. Symp. on Frontiers in Offshore Geotechnics (ISFOG), S. Gourvenec and M. Cassidy, eds., Taylor & Francis, Rotterdam, 981–989.
Lunne, T., Robertson, P. K., and Powell, J. J. M. (1997). Cone penetration testing in geotechnical practice, Chapman & Hall, London.
Mitchell, J. K., and Soga, K. (2005). Fundamentals of soil behavior, 3rd Ed., Wiley, New York.
Nash, D. F. T., Powell, J. J. M., and Lloyd, I. M. (1992). “Initial investigations of the soft clay test site at Bothkennar.” Geotechnique, 42(2), 163–181.
Peuchen, J., Adrichem, J., and Hefer, P. A. (2005). “Practice notes on push-in penetrometers for offshore geotechnical investigation,” Proc., Int. Symp. on Frontiers in Offshore Geotechnics (ISFOG), Taylor and Francis, Rotterdam, The Netherlands, 973–979.
Peuchen, J., and Mayne, P. (2007). “Rate effects in vane shear testing.” Proc., 6th Int. Offshore Site Investigation and Geotechnics Conf., Society for Underwater Technology, London, 187–193.
Randolph, M. F. (2004). “Characterisation of soft sediments for offshore applications.” Proc., ISC-2: 2nd Int. Conf. on Site Characterization, A. Viana da Fonseca and P. W. Mayne, eds., Mill Press, The Netherlands, 209–232.
Randolph, M. F., and Andersen, K. H. (2006). “Numerical analysis of T-bar penetration in soft clay.” Int. J. Geomech., 6(6), 411–420.
Stewart, D. P., and Randolph, M. F. (1991). “A new site investigation tool for the centrifuge.” Proc. Int. Conf. on Centrifuge Modelling—Centrifuge 91, H. Y. Ko and F. G. McLean, eds., 91, 531–538.
Watson, P. G., Newson, T. A., and Randolph, M. F. (1998). “Strength profiling in soft offshore soils.” Proc., 1st Int. Conf. on Site Characterization—ISC ’98, Vol. 2, A.-B. Huang and P. W. Mayne, eds., Mill Press, The Netherlands, 1389–1394.
Yafrate, N. J., and DeJong, J. T. (2005). “Considerations in evaluating the remoulded undrained shear strength from full-flow penetrometer cycling.” Proc., Int. Symp. on Frontiers in Offshore Geotecnics (ISFOG), S. Gourvenec and M. Cassidy, eds., Taylor & Francis, Rotterdam, 991–997.
Yafrate, N. J., and DeJong, J. T. (2006). “Interpretation of sensitivity and remolded shear strength with full-flow penetrometers.” Proc., ISOPE-06: Int. Society for Offshore and Polar Engineering, J. S. Chung, S. W. Hong, P. W. Marshall, T. Komai, and W. Koterayama, eds., ISOPE, Cupertino, Calif., 572–577.
Yafrate, N. J., DeJong, J. T., and DeGroot, D. J. (2007). “The influence of full-flow penetrometer area ratio on undrained strength measurements.” Proc., 6th Int. Conf. on Offshore Site Investigation and Geotechnics, Society for Underwater Technology (SUT), London, 461–468.
Zhou, H., and Randolph, M. F. (2009). “Resistance of full-flow penetrometers in rate-dependent and strain-softening clay.” Geotechnique, 59(2), 79–86.
Information & Authors
Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 135 • Issue 9 • September 2009
Pages: 1179 - 1189
Copyright
© 2009 ASCE.
History
Received: Feb 27, 2008
Accepted: Jan 17, 2009
Published online: Aug 14, 2009
Published in print: Sep 2009
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.