Undrained Bearing Capacity of Deeply Buried Flat Circular Footings under General Loading
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 138, Issue 3
Abstract
Estimation of a footing’s bearing capacity under general loading is a topic of wide interest, especially for the offshore energy industry. Although there have been several studies in the past few decades on shallow footings under general loading, limited work has been done for deeply buried footings. This paper presents results of a numerical investigation into the undrained bearing capacity of deeply buried flat circular footings in clay of both uniform and linearly increasing shear strength profiles. The footings’ uniaxial bearing capacities and failure surfaces under combined vertical, horizontal, and moment loading are reported. The results are analyzed in the context of application by the mobile jack-up industry, for which understanding of the circular spudcan footing’s bearing capacity under general loading is required for site-specific assessments. The paper also presents a parametric study on the effect of a footing’s aspect ratio (thickness/diameter) on its bearing capacity. To conclude, a closed-form expression is proposed to formulate the failure surfaces of the footings under general loading.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The first author is the recipient of a University of Western Australia SIRF scholarship and an Australia-China Natural Gas Technology Partnership Fund Ph.D. top-up scholarship. The funding support from the second author’s UWA Research Development Award is gratefully acknowledged. The third author acknowledges the support of the Australian Research Council through his Future Fellowship and the Lloyd’s Register Educational Trust (LRET), an independent charity working to achieve advances in transportation, science, engineering and technology education, and training and research worldwide for the benefit of all.
References
Bransby, M. F., and Randolph, M. F. (1998). “Combined loading of skirted foundations.” Geotechnique, 48(5), 637–655.
Bransby, M. F., and Yun, G. J. (2009). “The undrained capacity of skirted strip foundations under combined loading.” Geotechnique, 59(2), 115–125.
Brinch Hansen, J. (1970). “A revised and extended formula for bearing capacity.” Bulletin No. 28, Danish Geotechnical Institute, Copenhagen, Denmark, 5–11.
Butterfield, R., Houlsby, G. T., and Gottardi, G. (1997). “Standardized sign conventions and notation for generally loaded foundations.” Geotechnique, 47(5), 1051–1054.
Cassidy, M. J., Randolph, M. F., and Byrne, B. W. (2006). “A plasticity model describing caisson behaviour in clay.” Appl. Ocean Res., 28(5), 345–358.
Davis, E. H., and Booker, J. R. (1973). “The effect of increasing strength with depth on the bearing capacity of clays.” Geotechnique, 23(4), 551–563.
Dassault Systèmes (2007). ABAQUS analysis user’s manual, Simula Corp., Providence, RI.
Elkhatib, S. (2006). “The behaviour of drag-in plate anchors in soft cohesive soils.” Ph.D. thesis, Univ. of Western Australia, Perth, Australia.
Elkhatib, S., and Randolph, M. F. (2004). “Finite element modelling of drag-in plate anchors in clay.” 9th Int. Symp. on Numerical Methods in Geomechanics, A A Balkema, Netherlands, 541–547.
Gourvenec, S. (2008). “Effect of embedment on the undrained capacity of shallow foundations under general loading.” Geotechnique, 58(3), 177–185.
Gourvenec, S., and Barnett, S. (2011). “Undrained failure envelope for skirted foundations under general loading.” Geotechnique, 61(3), 263–270.
Gourvenec, S., and Randolph, M. (2003). “Effect of strength non-homogeneity on the shape of failure envelopes for combined loading of strip and circular foundations on clay.” Geotechnique, 53(6), 575–586.
Hossain, M. S., and Randolph, M. F. (2009a). “New mechanism-based design approach for spudcan foundations on single layer clay.” J. Geotech. Geoenviron. Eng., 135(9), 1264–1274.
Hossain, M. S., and Randolph, M. F. (2009b). “Effect of strain rate and strain sofening on the penetration resistance of spudcan foundations on clay.” Int. J. Geomech., 9(3), 122–132.
Houlsby, G. T., and Cassidy, M. J. (2002). “A plasticity model for the behaviour of footings on sand under combined loading.” Geotechnique, 52(2), 117–129.
Houlsby, G. T., and Martin, C. M. (2003). “Undrained bearing capacity factors for conical footings on clay.” Geotechnique, 53(5), 513–520.
Martin, C. M. (1994). “Physical and numerical modelling of offshore foundations under combined loads.” Ph.D. thesis, Univ. of Oxford, Oxford, UK.
Martin, C. M., and Houlsby, G. T. (2000). “Combined loading of spudcan foundations on clay: Laboratory tests.” Geotechnique, 50(4), 325–338.
Martin, C. M., and Houlsby, G. T. (2001). “Combined loading of spudcan foundations on clay: Numerical modelling.” Geotechnique, 51(8), 687–699.
Martin, C. M., and Randolph, M. (2001). “Applications of lower and upper bound theorems of plasticity to collapse of circular foundations.” Proc., 10th Int. Conf. on Computer Methods and Advances in Geomechanics, Vol. 2, A A Balkema, Netherlands, 1417–1428.
Meyerhof, G. G. (1953). “The bearing capacity of foundations under eccentric and inclined loads.” Proc., 3rd Int. Conf. on Soil Mechanics and Foundation Engineering, Vol. 1, Zurich, Switzerland, 440–445.
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.
Skempton, A. W. (1951). “The bearing capacity of clays.” Proc., Build. Res. Congr., 1, 180–189.
Society of Naval Architects and Marine Engineers (SNAME). (2008). “Recommended practice for site specific assessment of mobile jack-up units.” T&R Bulletin 5-5A, 1st Ed., 3rd Rev. Jersey City, NJ.
Taiebat, H. A., and Carter, J. P. (2000). “Numerical studies of the bearing capacity of shallow foundations on cohesive soil subjected to combined loading.” Geotechnique, 50(4), 409–418.
Templeton, J. S. (2009). “Spud can 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.
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.
Vlahos, G., Cassidy, M. J., and Martin, C. M. (2008). “Experimental investigation of the system behaviour of a model three-legged jack-up on clay.” Appl. Ocean Res., 30(4), 323–337.
Yun, G., and Bransby, M. F. (2007). “The horizontal-moment capacity of embedded foundations in undrained soil.” Can. Geotech. J., 44(4), 409–424.
Zhang, Y., Bienen, B., Cassidy, M. J., and Gourvenec, S. (2010). “Undrained bearing capacity of deeply embedded foundations under general loading.” Proc., 2nd Int. Symp. on Frontiers in Offshore Geotechnics, Taylor & Francis Group, London, 691–696.
Information & Authors
Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 138 • Issue 3 • March 2012
Pages: 385 - 397
Copyright
© 2012 American Society of Civil Engineers.
History
Received: Sep 17, 2010
Accepted: Jul 21, 2011
Published online: Jul 25, 2011
Published in print: Mar 1, 2012
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.