Effect of Installation on the Bearing Capacity of a Spudcan under Combined Loading in Soft Clay
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 140, Issue 7
Abstract
Previous numerical analyses of the bearing capacity of embedded footing under combined vertical, horizontal, and moment loading have been based on the assumption that the foundation is wished-in-place, surrounded by undisturbed soil. Under these conditions, the large displacement and remolding of the soil during the footing installation are not accounted for. This assumption results in an overestimation of the capacity. This paper presents results of the size and shape of the bearing capacity surface of spudcan footing in soft clay that accounts for the effects of installation in the modeling. Results for soil sensitivities between one and five and for embedment depths up to three diameters are provided. The findings have practical application in the site-specific assessment of mobile jack-up platforms in soft clay.
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Acknowledgments
The first author received a University of Western Australia SIRF scholarship and an Australia-China Natural Gas Technology Partnership Fund Ph.D. top-up scholarship during which time the work described in this paper was performed. The third author is the recipient of an Australian Research Council (ARC) Laureate Fellowship (FL130100059) and holds the Chair of Offshore Foundations from Lloyd’s Register Foundation (LRF). LRF, a United Kingdom-registered charity and sole shareholder of Lloyd’s Register Group, invests in science, engineering, and technology for public benefit, worldwide. He gratefully acknowledges this support. The fourth author acknowledges funding support from an ARC Postdoctoral Fellowship (DP11010163).
References
Andersen, K. H., and Jostad, H. P. (2004). “Shear strength along inside of suction anchor skirt wall in clay.” Proc., Offshore Technology Conf., Offshore Technology Conference, Houston.
Bienen, B., Byrne, B. W., Houlsby, G. T., and Cassidy, M. J. (2006). “Investigating six-degree-of-freedom loading of shallow foundations on sand.” Geotechnique, 56(6), 367–379.
Cassidy, M. J. (2007). “Experimental observations of the combined loading behaviour of circular footings on loose silica sand.” Geotechnique, 57(4), 397–401.
Cassidy, M. J., Byrne, B. W., and Randolph, M. F. (2004). “A comparison of the combined load behaviour of spudcan and caisson foundations on soft normally consolidated clay.” Geotechnique, 54(2), 91–106.
Chatterjee, S., Randolph, M. F., and White, D. J. (2012). “The effects of penetration rate and strain softening on the vertical penetration resistance of seabed pipelines.” Geotechnique, 62(7), 573–582.
Chen, W., and Randolph, M. F. (2007). “Uplift capacity of suction caissons under sustained and cyclic loading in soft clay.” J. Geotech. Geoenviron. Eng., 1352–1363.
Dassault Systèmes. (2011). ABAQUS analysis user's manual, Simula, Providence, RI.
Einav, I., and Randolph, M. F. (2005). “Combined upper bound and strain path methods for evaluating the penetration process.” Int. J. Numer. Methods Eng., 63(14), 1991–2016.
Elkhatib, S. (2006). “The behaviour of drag-in plate anchors in soft cohesive soils.” Ph.D. thesis, Univ. of Western Australia, Perth, Australia.
Gan, C. T., Leung, C. F., Cassidy, M. J., Gaudin, C., and Chow, Y. K. (2012). “Effect of time on spudcan-footprint interaction in clay.” Geotechnique, 62(5), 401–413.
Gottardi, G., Houlsby, G. T., and Butterfield, R. (1999). “Plastic response of circular footings on sand under general planar loading.” Geotechnique, 49(4), 453–469.
Gourvenec, S. (2008). “Effect of embedment on the undrained capacity of shallow foundations under general loading.” Geotechnique, 58(3), 177–185.
Hodder, M., and Cassidy, M. J. (2010). “A plasticity model for predicting the vertical and lateral behaviour of pipelines in clay soils.” Geotechnique, 60(4), 247–263.
Hossain, M. S., Hu, Y., Randolph, M. F., and White, D. J. (2005). “Limiting cavity depth for spudcan foundations penetrating clay.” Geotechnique, 55(9), 679–690.
Hossain, M. S., and Randolph, M. F. (2009a). “Effect of strain rate and strain sofening on the penetration resistance of spudcan foundations on clay.” Int. J. Geomech., 122–132.
Hossain, M. S., and Randolph, M. F. (2009b). “New mechanism-based design approach for spudcan foundations on single layer clay.” J. Geotech. Geoenviron. Eng., 1264–1274.
Hu, H. J. E., Tho, K. K., Gan, C. T., Palmer, A. C., and Leung, C. F. (2010). “Repeated loading and unloading of the seabed.” Proc., 2nd Int. Symp. on Frontiers in Offshore Geotechnics (ISFOG), CRC Press/Balkema, Leiden, Netherlands, 347–352.
Hu, P., Wang, D., Cassidy, M. J., and Yang, Q. (2012). “Large deformation analysis of spudcan penetration into sand overlying normally consolidated clay.” Proc., Constitutive Modeling of Geomaterial, SSGG, Beijing, 723–733.
Hu, Y., and Randolph, M. F. (1998). “A practical numerical approach for large deformation problems in soil.” Int. J. Numer. Anal. Methods Geomech., 22(5), 327–350.
ISO. (2012). “Petroleum and natural gas industries—Site-specific assessment of mobile offshore units—Part 1: Jack-ups.” ISO 19905-1, Geneva.
Kvalstad, T. J., Nadim, F., and Harbitz, C. B. (2001). “Deepwater geohazards: Geotechnical concerns and solutions.” Proc., Offshore Technology Conf., Offshore Technology Conference, Houston.
Martin, C. M., and Houlsby, G. T. (2000). “Combined loading of spudcan foundations on clay: laboratory tests.” Geotechnique, 50(4), 325–338.
Menzies, D., and Roper, R. (2008). “Comparison of jackup rig spudcan penetration methods in clay.” Proc., Offshore Technology Conf., Offshore Technology Conference, Houston.
O'Neill, M. P., Bransby, M. F., and Randolph, M. F. (2003). “Drag anchor fluke-soil interaction in clays.” Can. Geotech. J., 40(1), 78–94.
Randolph, M. F. (2004). “Characterization of soft sediments for offshore applications.” Proc., 2nd Int. Conf. on Site Characterization, Millpress, Rotterdam, Netherlands, 209–231.
Randolph, M. F., Wang, D., Zhou, H., Hossain, M. S., and Hu, Y. (2008). “Large deformation finite element analysis for offshore applications.” Proc., 12th Int. Conf. of the Int. Association for Computer Methods and Advances in Geomechanics, IACMAG, Goa, India, 3307–3318.
Society of Naval Architects and Marine Engineers. (2008). “Recommended practice for site specific assessment of mobile jack-up units.” T&R Bulletin 5-5A, 1st Ed., 3rd Revision, Jersey City, NJ.
Tan, F. S. C. (1990). “Centrifuge and theoretical modelling of conical footings on sand.” Ph.D. thesis, Cambridge Univ., Cambridge, U.K.
Templeton, J. S. (2009). “Spudcan fixity in clay, further results from a study for IADC.” Proc., 12th Int. Conf. on The Jack-Up Platform Design, Construction & Operation, City Univ. London, London.
Templeton, J. S., Brekke, J. N., and Lewis, D. R. (2005). “Spud can fixity in clay, final findings of a study for IADC.” Proc., 10th Int. Conf. on the Jack-Up Platform Design, Construction & Operation, City Univ. London, London.
Tho, K. K., Leung, C. F., Chow, Y. K., and Swaddiwudhipong, S. (2012). “Eulerian finite-element technique for analysis of jack-up spudcan penetration.” Int. J. Geomech., 64–73.
Tian, Y., Gaudin, C., Cassidy, M. J., and Randolph, M. F. (2013). “Considerations on the design of keying flap of plate anchors.” J. Geotech. Geoenviron. Eng., 1156–1164.
Wang, D., Gaudin, C., and Randolph, M. F. (2013a). “Large deformation finite element analysis investigating the performance of anchor keying flap.” Ocean Eng., 59(1), 107–116.
Wang, D., Hu, Y., and Randolph, M. F. (2010a). “Three-dimensional large deformation finite-element analysis of plate anchors in uniform clay.” J. Geotech. Geoenviron. Eng., 355–365.
Wang, D., Randolph, M. F., and White, D. J. (2013b). “A dynamic large deformation finite element method based on mesh regeneration.” Comput. Geotech., 54, 192–201.
Wang, D., White, D. J., and Randolph, M. F. (2010b). “Large-deformation finite element analysis of pipe penetration and large-amplitude lateral displacement.” Can. Geotech. J., 47(8), 842–856.
Zhang, Y., Bienen, B., and Cassidy, M. J. (2013). “Development of a combined VHM loading apparatus for a geotechnical drum centrifuge.” Int. J. Phys. Modell. Geotech., 13(1), 13–30.
Zhang, Y., Bienen, B., Cassidy, M. J., and Gourvenec, S. (2011). “The undrained bearing capacity of a spudcan foundation under combined loading in soft clay.” Mar. Structures, 24(4), 459–477.
Zhang, Y., Bienen, B., Cassidy, M. J., and Gourvenec, S. (2012). “Undrained bearing capacity of deeply buried flat circular footings under general loading.” J. Geotech. Geoenviron. Eng., 385–397.
Zhou, H., and Randolph, M. F. (2007). “Computational techniques and shear band development for cylindrical and spherical penetrometers in strain-softening clay.” Int. J. Geomech., 287–295.
Zhou, H., and Randolph, M. F. (2009). “Resistance of full-flow penetrometers in rate-dependent and strain-softening clay.” Geotechnique, 59(2), 79–86.
Zienkiewicz, O. C., and Zhu, J. Z. (1992). “The superconvergent patch recovery and a posteriori error estimates. Part 1: The recovery technique.” Int. J. Numer. Methods Eng., 33(7), 1331–1364.
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Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 140 • Issue 7 • July 2014
Copyright
© 2014 American Society of Civil Engineers.
History
Received: Feb 28, 2013
Accepted: Feb 25, 2014
Published online: Mar 26, 2014
Published in print: Jul 1, 2014
Discussion open until: Aug 26, 2014
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