Installation of Stiffened Caissons in Nonhomogeneous Clays
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 142, Issue 2
Abstract
A significant difference between predicted and measured installation resistance of stiffened suction caissons was identified due to the existing uncertainty regarding the mobilized soil-flow mechanisms. This paper describes an extensive investigation of stiffened-caisson penetration in nonhomogeneous clays undertaken through large deformation finite-element (LDFE) analysis to provide insight into the soil behavior during installation of a caisson. The soil-flow mechanisms around and between stiffeners, and inside and outside of the caisson, and the corresponding penetration resistances were presented from a parametric study, exploring a range of dimensionless parameters related to stiffened-caisson geometry, caisson roughness, and soil strength nonhomogeneity. The LDFE results were compared with centrifuge test data in terms of the soil-flow mechanisms and penetration resistance profile, with good agreement obtained. Three interesting features in the mobilized soil-flow mechanisms inside the caisson were observed: (1) soil started to infill the gap between the bottom two stiffeners when the bottom stiffener penetration reached ( is the critical depth of rotational soil flow around bottom stiffener); (2) soil started to infill the gap between the second and third bottom stiffeners when the second stiffener penetration reached ( is the critical depth of soil backflow into gaps above the 2nd stiffener); (3) profound soil heave due to significant inward flow and the presence of stiffeners and gap between stiffeners. Both and were shown to be a function of the stiffener-width to caisson-diameter ratio, normalized soil strength at the mudline, and soil strength nonhomogeneity. To predict the penetration resistance profile in the field, a rational analytical penetration model, based on the revealed soil-flow mechanisms, was proposed. The LDFE data were used to calibrate the model. Very good agreements were obtained when the proposed model was validated against measured data from field installation and centrifuge tests.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The research presented here was undertaken with support from National Nature Science Foundation of China (No. U1134207 and B13024), the Department of Industry, Innovation, Science, Research and Tertiary Education (DIISRTE) Australia China Science and Research Fund (Group Mission ACSRF00300) and the Australian Research Council (ARC) Discovery Grant (DP1096764). The second author is an ARC Discovery Early Career Researcher Award (DECRA) Fellow and is supported by the ARC Project DE140100903. The work forms part of the activities of the Centre for Offshore Foundation Systems (COFS), currently supported as a node of the Australian Research Council Centre of Excellence for Geotechnical Science and Engineering and as a Centre of Excellence by the Lloyd’s Register Foundation. This support is gratefully acknowledged, as is the benefit of discussion with Dr. Long Yu, Dr. Dong Wang, and Dr. Xu Li.
References
Andersen, K., et al. (2005). “Suction anchors for deepwater applications.” Proc., 1st Int. Symp. on Frontiers in Offshore Geotechnics (ISFOG), Taylor & Francis, London, 3–30.
API (American Petroleum Institute). (2007). “API recommended practice 2A-WSD.” Washington, DC.
Aubeny, C. P., Shi, H., and Murff, J. D. (2005). “Collapse loads for a cylinder embedded in trench in cohesive soil.” Int. J. Geomech., 320–325.
Carter, J. P., and Balaam, N. P. (1995). AFENA users’ manual, Centre for Geotechnical Research, Dept. of Civil Engineering, Univ. of Sydney, Sydney, Australia.
Chen, W., and Randolph, M. F. (2007). “External radial stress changes and axial capacity for suction caissons in soft clay.” Geotechnique, 57(6), 499–511.
Chen, W., Zhou, H., and Randolph, M. F. (2009). “Effect of installation method on external shaft friction of caissons in soft clay.” J. Geotech. Geoenviron. Eng., 605–615.
Colliat, J.-L., Dendani, H., Puech, A., and Nauroy, J.-F. (2011a). “Gulf of Guinea deepwater sediments: Geotechnical properties, design issues and installation experiences.” Proc., 2nd Int. Symp. Frontiers in Offshore Geotechnics, S. M. Gourvenec and D. J. White, eds., Taylor & Francis, London, 59–86.
Colliat, J.-L., et al. (2011b). “Centrifuge testing of suction piles in deepwater Nigeria clay– Effect of stiffeners and setup time.” Proc., 2nd Int. Symp. Frontiers in Offshore Geotechnics, S. M. Gourvenec and D. J. White, eds., Taylor & Francis, London, 729–734.
Dendani, H. (2003). “Suction anchors: some critical aspects for their design and installation in clayey soils.” Proc., Offshore Technology Conf., OTC 15376, Houston.
Dendani, H., and Colliat, J.-L. (2002). “Girassol: design analysis and installation of the suction anchors.” Proc., Offshore Technology Conf., OTC 14209, Houston.
Dutt, R. N., and Ehlers, C. J. (2009). “Set-up of large diameter driven pipe piles in deepwater normally consolidated high plasticity clays.” Proc., 28th Int. Conf. of Ocean, Offshore and Artic Engineering, ASME, New York.
Erbrich, C. T., and Hefer, P. (2002). “Installation of the Laminaria suction piles—A case history.” Proc., Offshore Technology Conf., OTC 14240, Houston.
Gaudin, C., O’Loughlin, C. D., Hossain, M. S., Randolph, M. F., and Colliat, J.-L. (2014). “Installation of suction caissons in Gulf of Guinea clay.” Proc., 8th Int. Conf. on Physical Modelling in Geotechnics, Vol. 1, Taylor & Francis, London, 493–499.
Ghosh, S., and Kikuchi, N. (1991). “An arbitrary Lagrangian-Eulerian finite element method for large deformation analysis of elastic-viscoplastic solids.” Comput. Meth. Appl. Mech. Eng., 86(2), 127–188.
Herrmann, L. R. (1978). “Finite element analysis of contact problems.” J. Eng. Mech. Div., 104(EM5), 1043–1057.
Hossain, M. S., Lehane, B. M., Hu, Y., and Gao, Y. (2012). “Soil flow mechanisms around and between stiffeners of caissons during installation in clay.” Can. Geotech. J., 49(4), 442–459.
House, A. R., and Randolph, M. F. (2001). “Installation and pull-out capacity of stiffened suction caissons in cohesive sediments.” Proc., 11th Int. Offshore and Polar Engineering Conf., Vol. 2, International Society of Offshore and Polar Engineers, CA, 574–580.
Hu, Y., and Randolph, M. F. (1998). “A practical numerical approach for large deformation problems in soil.” Int. J. Numer. Anal. Meth. Geomech., 22(5), 327–350.
Liyanapathirana, D. S (2009). “Arbitrary Lagrangian Eulerian based finite element analysis of cone penetration in soft clay.” Comput. Geotech., 36(5), 851–860.
Low, H. E., Lunne, T., Andersen, K. H., Sjursen, M. A., Li, X., and Randolph, M. F. (2010). “Estimation of intact and remoulded undrained shear strengths from penetration tests in soft clays.” Géotechnique, 60(11), 843–859.
Lu, Q., Randolph, M. F., Hu, Y., and Bugarski, I. (2004). “A numerical study of cone penetration in clay.” Geotechnique, 54(4), 257–267.
Mana, D. S. K., Gourvenec, S. M., and Randolph, M. F. (2013). “Experimental investigation of reverse end bearing of offshore shallow foundations.” Can. Geotech. J., 50(10), 1022–1033.
Martin, C. M., and Randolph, M. F. (2006). “Upper-bound analysis of lateral pile capacity in cohesive soil.” Geotechnique, 56(2), 141–145.
Randolph, M. F., and House, A. R. (2002). “Analysis of suction caisson capacity in clay.” Proc., Offshore Technology Conf., OTC 14236, Houston.
Randolph, M. F., Low, H. E., and Zhou, H. (2007). “In situ testing for design of pipeline and anchoring systems.” Proc. 6th Int. Offshore Site Investigation and Geotechnics Conf. Confronting New Challenges and Sharing Knowledge, Vol. 1, Society of Underwater Technology, London, 251–262.
Randolph, M. F., O’Neill, M. P., Stewart, D. P., and Erbrich, C. T. (1998). “Performance of suction anchors in fine-grained calcareous soils.” Proc., Offshore Technology Conf., OTC 8831, Houston.
Randolph, M. F., and White, D. J. (2008). “Upper-bound yield envelopes for pipelines at shallow embedment in clay.” Geotechnique, 58(4), 297–301.
Vásquez, L. F. G., Maniar, D. R., and Tassoulas, J. L. (2010). “Installation and axial pullout of suction caissons: numerical modelling.” J. Geotech. Geoenviron. Eng., 1137–1147.
Westgate, Z. J., Tapper, L., Lehane, B. M., and Gaudin, C. (2009). “Modelling the installation of stiffened caissons in overconsolidated clay.” Proc., 28th Int. Conf. on Ocean, Offshore and Arctic Engineering, ASME, New York, 119–126.
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.
Zhou, H., and Randolph, M. F. (2006). “Large deformation analysis of suction caisson installation in clay.” Can. Geotech. J., 43(12), 1344–1357.
Zhou, M., Hossain, M. S., and Hu, Y. (2015). “Large penetration FE analysis of stiffened caissons in NC clays with a sandwiched stiff clay layer.” Computer methods and recent advances in geomechanics–Oka, Murakami, R. Uzuoka and S. Kimoto, eds., Taylor & Francis, London.
Information & Authors
Information
Published In
Copyright
© 2015 American Society of Civil Engineers.
History
Received: Dec 15, 2014
Accepted: Jun 4, 2015
Published online: Sep 9, 2015
Published in print: Feb 1, 2016
Discussion open until: Feb 9, 2016
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.