Abstract
Results of finite-element analyses calculating the undrained capacities of skirted circular foundations under uniaxial vertical, horizontal, and moment loading are presented. Parallel finite-element analyses using both the Tresca failure criterion and the modified cam clay (MCC) model are reported. The variations in capacity are presented as functions of embedment and soil-strength heterogeneity as a series of graphs. Closed-form formulas of uniaxial capacities are also provided. To account for the complexity in the results, a novel method of separating the contributions of soil above and beneath the skirt tip and for the constant and linearly varying components of the undrained shear-strength profile is outlined. This method can be used to estimate the undrained ultimate uniaxial capacity factors of skirted circular foundations in clay for any given embedment ratio and strength heterogeneity. Its versatility is also shown through validation against previously published embedded strip footing data. The results provide both equations for engineers to use in design and a database that can be used in future research to calculate and express the consolidated undrained capacity under combined loading.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
This work forms part of the activities of the Centre for Offshore Foundation Systems (COFS), which is supported by the Lloyd’s Register Foundation as a Centre of Excellence and now forms one of the primary nodes of the Australian Research Council (ARC) Centre of Excellence for Geotechnical Science and Engineering. Lloyd’s Register Foundation helps to protect life and property by supporting engineering-related education, public engagement, and the application of research.
References
ABAQUS [Computer software]. Dassault Systèmes, Providence, RI.
Bienen, B., Gaudin, C., Cassidy, M. J., Rausch, L., Purwana, O. A., and Krisdani, H. (2012). “Numerical modelling of a hybrid skirted foundation under combined loading.” Comput. Geotech., 45(2012), 127–139.
Bransby, M. F., and Randolph, M. F. (1997). “Shallow foundations subjected to combined loading.” Proc., 9th Int. Conf. on Computer Methods and Advances in Geomechanics, A.A. Balkema, Rotterdam, Netherlands, 1947–1952.
Bransby, M. F., and Randolph, M. F. (1998). “Combined loading of skirted foundations.” Géotechnique, 48(5), 637–655.
Bransby, M. F., and Randolph, M. F. (1999). “The effects of embedment on the undrained response of caisson foundations to combined loadings.” Soils Found., 39(4), 19–33.
Bransby, M. F., and Yun, G. J. (2009). “The undrained capacity of skirted strip foundations under combined loading.” Géotechnique, 59(2), 115–125.
Chatterjee, S., Yan, Y., Randolph, M. F., and White, D. J. (2012). “Elastoplastic consolidation beneath shallowly embedded offshore pipelines.” Géotechnique Lett., 2(2), 73–79.
Cox, A. D., Eason, G., and Hopkins, H. G. (1961). “Axially symmetric plastic deformation of soils.” Phil. Trans. R. Soc. London Ser. A, 254, 1–45.
Fu, D., Gaudin, C., Tian, Y., Bienen, B., and Cassidy, M. J. (2015). “Effect of preloading with consolidation on undrained bearing capacity of skirted circular footings.” Géotechnique, 65(3), 231–246.
Gourvenec, S. (2007). “Failure envelopes for offshore shallow foundations under general loading.” Géotechnique, 57(9), 715–728.
Gourvenec, S. (2008). “Effect of embedment on the undrained capacity of shallow foundations under general loading.” Géotechnique, 58(3), 177–185.
Gourvenec, S., and Barnett, S. (2011). “Undrained failure envelope for skirted foundations under general loading.” Géotechnique, 61(3), 263–270.
Gourvenec, S., and Mana, D. K. S. (2011). “Undrained vertical bearing capacity factors for shallow foundations.” Géotechnique Lett., 1(4), 101–108.
Gourvenec, S., and Randolph, M. F. (2003). “Effect of strength non-homogeneity on the shape and failure envelopes for combined loading of strip and circular foundations on clay.” Géotechnique, 53(6), 575–586.
Gourvenec, S., Vulpe, C., and Murphy, T. G. (2014). “A method for predicting the consolidated undrained bearing capacity of shallow foundations.” Géotechnique, 64(3), 215–225.
Houlsby, G. T., and Wroth, C. P. (1983). “Calculation of stresses on shallow penetrometers and footings.” Proc., Int. Union of Theoretical and Applied Mechanics/Int. Union of Geodesy and Geophysics Symp. on Seabed Mechanics, Springer, Rotterdam, Netherlands, 107–112.
Hu, Y., Randolph, M. F., and Watson, P. G. (1999). “Bearing response of skirted foundations on non-homogeneous soil.” J. Geotech. Eng. Div., 924–935.
Mana, D. S. K., Gourvenec, S., and Randolph, M. F. (2010). “A numerical study of the vertical bearing capacity of skirted foundations.” Proc., 2nd Int. Symp. on Frontiers in Offshore Geotechnics, Taylor & Francis, London, 433–438.
Martin, C. M. (2001). “Vertical bearing capacity of skirted circular foundations on Tresca soil.” Proc., 15th Int. Conf. on Soil Mechanics and Geotechnical Engineering, CRC Press, Boca Raton, FL, 743–746.
Martin, C. M., and Randolph, M. F. (2001). “Application of the lower and upper bound theorems of plasticity to collapse of circular foundations.” Proc., 10th Int. Conf. on International Association for Computer Methods and Advances in Geomechanics, CRC Press, Boca Raton, FL, 1417–1428.
Randolph, M. F., and Puzrin, A. M. (2003). “Upper bound limit analysis of circular foundations on clay under general loading.” Géotechnique, 53(9), 785–796.
Roscoe, K. H., and Burland, J. B. (1968). “On the generalised stress-strain behaviour of ‘wet clay’.” Engineering plasticity, Cambridge University Press, Cambridge, U.K., 535–609.
Tani, K., and Craig, W. H. (1995). “Bearing capacity of circular foundations on soft clay of strength increasing with depth.” Soils Found., 35(2), 37–47.
Vulpe, C. (2015). “Design method for the undrained capacity of skirted circular foundations under combined loading: Effect of deformable soil plug.” Géotechnique, 65(8), 669–683.
Vulpe, C., Gourvenec, S., and Power, M. (2014). “A generalised failure envelop for undrained capacity of circular shallow foundations under general loading.” Géotechnique Lett., 4(3), 187–196.
Wroth, C. P. (1984). “The interpretation of in-situ tests: 24th Rankine Lecture.” Géotechnique, 34(4), 449–489.
Yun, G., and Bransby, M. F. (2007). “The undrained vertical bearing capacity of skirted foundations.” Soils Found., 47(3), 493–505.
Information & Authors
Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 143 • Issue 7 • July 2017
Copyright
©2017 American Society of Civil Engineers.
History
Received: Jun 24, 2016
Accepted: Dec 5, 2016
Published ahead of print: Mar 7, 2017
Published online: Mar 8, 2017
Published in print: Jul 1, 2017
Discussion open until: Aug 8, 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.