Experiments Using a Novel Penetrometer to Assess Changing Strength of Clay during Remolding and Reconsolidation
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 143, Issue 4
Abstract
The process of remolding and subsequent recovery of soil shear strength is a common geotechnical problem, especially in the offshore environment, where foundations and pipelines are subjected to intermittent operational and environmental loads. A novel vertically oriented penetrometer (VOP) was used in a centrifuge testing program to study the changing strength of normally consolidated kaolin from successive disturbance and reconsolidation events. The VOP is used to determine soil shear strength via an interpretation akin to the laterally loaded pile. The test series involved cyclic movement of the VOP at velocities ranging from 0.3 to , with a corresponding 100-fold variation in the duration of each cycle. For the VOP tests at low velocities with high cyclic periods, the soil resistance initially reduces, but then shows an increase that scales with the elapsed time, indicating reconsolidation. Ultimately, if the cycling continues for sufficient time, the recovery in strength from reconsolidation can exceed the weakening from remolding. A previously published framework using critical-state soil mechanics concepts is shown to capture the changing resistance well.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
This research was supported by the Minerals and Energy Research Institute of Western Australia, and by BP, BHP Billiton, Chevron, Petrobras, Shell, and Woodside. The financial support of all the participants is gratefully acknowledged. The authors are grateful to Noel Boylan, Don Herley, Phil Hortin, and Shane De Catania for their technical assistance. The first author is also grateful for the financial support received from the Ministry of Higher Education Malaysia (MOHE) and Universiti Malaysia Sarawak (UNIMAS).
References
Boukpeti, N., White, D. J., Randolph, M. F., and Low, H. E. (2012). “Strength of fine-grained soils at the solid-fluid transition.” Géotechnique, 62(3), 213–226.
Einav, I., and Randolph, M. F. (2005). “Combining upper bound and strain path methods for evaluating penetration resistance.” Int. J. Numer. Methods Eng., 63(14), 1991–2016.
Hyde, A. F. L., Higuchi, T., and Yasuhara, K. (2007). “Postcyclic recompression, stiffness, and consolidated cyclic strength of silt.” J. Geotech. Geoenviron. Eng., 416–423.
Ohara, S., and Matsuda, H. (1988). “Study on the settlement of saturated clay layer induced by cyclic shear.” Soils Found., 28(3), 103–113.
Randolph, M. F., Low, H. E., and Zhou, H. (2007). “In situ testing for design of pipeline and anchoring systems.” Proc., 6th Int. Conf. on Offshore Site Investigation and Geotechnics, Society for Underwater Technology, London, 27–38.
Sahdi, F., Boylan, N., White, D. J., and Gaudin, C. (2010). “The influence of coloured dyes on the undrained shear strength of kaolin.” 7th Int. Conf. on Physical Modelling in Geotechnics, Taylor & Francis Group, London.
Sahdi, F., Gaudin, C., and White, D. J. (2014). “Strength properties of ultra-soft kaolin.” Can. Geotech. J., 51(4), 420–431.
Sahdi, F., White, D. J., Gaudin, C., Randolph, M. F., and Boylan, N. (2016). “Laboratory development of a vertically oriented penetrometer for shallow seabed characterization.” Can. Geotech. J., 53(1), 93–102.
Stewart, D. P. (1991). “Lateral loading of piled bridge abutments due to embankment construction.” Ph.D. thesis, Univ. of Western Australia, Perth, Australia.
Terzaghi, K., and Frohlich, O. K. (1936). Theorie der Setzung υon Tonschichten: Eine Einfuhrung in die Analytische Tonmechanik, Franz Deuticke, Leipzig, Germany (in German).
White, D. J., Gaudin, C., Boylan, N., and Zhou, H. (2010). “Interpretation of T-bar penetrometer tests at shallow embedment and in very soft soils.” Can. Geotech. J., 47(2), 218–229.
White, D. J., and Hodder, M. (2010). “A simple model for the effect on soil strength of episodes of remoulding and reconsolidation.” Can. Geotech. J., 47(7), 821–826.
Yasuhara, K., and Andersen, K. H. (1991). “Recompression of normally consolidated clay after cyclic loading.” Soils Found., 31(1), 83–94.
Zhou, H., and Randolph, M. F. (2009). “Numerical investigations into cycling of full-flow penetrometers in soft clay.” Géotechnique, 59(10), 801–812b.
Information & Authors
Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 143 • Issue 4 • April 2017
Copyright
©2016 American Society of Civil Engineers.
History
Received: Jul 22, 2015
Accepted: Aug 23, 2016
Published online: Nov 16, 2016
Published in print: Apr 1, 2017
Discussion open until: Apr 16, 2017
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.