Numerical Modeling of Spudcan Deep Penetration in Three-Layer Clays
Publication: International Journal of Geomechanics
Volume 15, Issue 6
Abstract
This paper reports the results from numerical modeling of spudcan deep penetration through three-layer clays. Two typical seabed strength profiles commonly encountered in the field, and identified as critical for potential punch-through failure, were considered: (1) uniform stiff-soft-stiff clay and (2) nonuniform clay with an interbedded stiff clay layer. Three-dimensional large deformation finite-element (LDFE) analyses were carried out with and without simulating strain softening and strain rate dependency of the shear strength. The results were compared with previously published LDFE results and centrifuge test data. A detailed parametric study was undertaken, varying the relevant range of layer thicknesses (relative to the spudcan diameter), strength ratios, normalized strength, and strength nonhomogeneity. Punch-through and rapid leg penetration (for stiff-over-soft) and squeezing (for the reverse) were demonstrated by the penetration resistance profiles and associated soil failure mechanisms. The results emphasized that the resistance profile from a spudcan continuous penetration in a three-layer sediment (e.g., stiff-soft-stiff) may be significantly different from the combined profiles resulting from two separate analyses on first-second layers and second-third layers, even if an appropriate depth factor is accounted for. For uniform stiff-soft-stiff clays, the presence of the bottom stiff clay layer within a short distance of one diameter affected spudcan bearing response in the top layer and suppressed the potential for punch-through failure (apart from rapid leg run for and ). A trapped soil plug beneath the advancing spudcan, following penetration of the top stiff layer, caused the bottom stiff layer to be sensed earlier and led to enhancement of the limiting squeezing depth. For nonuniform clay with an interbedded stiff layer, spudcan bearing response was dominated by squeezing (with limiting squeezing depth of approximately ) in the top soft layer and potential punch-through and rapid leg run (for and ) in the middle and bottom layers. In contrast to ISO recommendations, the soft soils in between the advancing spudcan base and the stronger layer did not squeeze out completely. Instead, some of the trapped material was forced into the underlying stronger layer. Punch-through distance was found to reduce significantly with increasing positive strength gradient of the bottom layer.
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 the University of Western Australia SIRF and UIS scholarships. The second author is an Australian Research Council (ARC) Discovery Early Career Researcher Award (DECRA) Fellow and is supported by the ARC Project DE140100903. The research presented here was undertaken with support from the ARC and the industry partner Keppel Offshore and Marine Pte Ltd, Singapore, through the ARC Linkage Project LP110100174. This 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.
References
ABAQUS/Explicit 6.10 [Computer software]. Velizy-Villacoublay, France, Dassault Systèmes.
AFENA [Computer software]. Sydney, NSW, Australia, Univ. of Sydney.
Aust, T. (1997). Accident to the mobile offshore drilling unit Maersk Victory on November 16, 1996, Mines and Energy Resources, Adelaide, South Australia.
Bennett and Associates. (2005). “Jack up units: A technical primer for the offshore industry professional.” 〈http://www.bennettoffshore.com/primer.html〉 (Aug. 25, 2014).
Brennan, R., Diana, H., Stonor, R. W. P., Hoyle, M. J. R., Cheng, C.-P., Roper, R. (2006). “Installing jackups in punch-through-sensitive clays.” Proc., Offshore Technology Conf., Offshore Technology Conference, Houston.
Brown, J. D., and Meyerhof, G. G. (1969). “Experimental study of bearing capacity in layered clays.” Proc., 7th Int. Conf. on Soil Mechanics and Foundation Engineering, Vol. 2, Sociedad Mexicana de Ingenieria Mecanica, Mexico, 45–51.
Carter, J. P., and Balaam, N. P. (1990). AFENA user’s manual, Centre for Geotechnical Research, Univ. of Sydney, Sydney, Australia.
Castleberry, J. P., II, and Prebaharan, N. (1985). “Clay crusts of the Sunda Shelf—A hazard to jack-up operations.” Proc., 8th Southeast Asian Geotechnical Conf., South East Asian Geotechnical Society, Pathumthani, Thailand, 40–48.
Chan, N. H. C., Paisley, J. M., and Holloway, G. L. (2008). “Characterization of soils affected by rig emplacement and Swiss cheese operations—Natuna Sea, Indonesia, a case study.” Proc., 2nd Jack-up Asia Conf. and Exhibition, AP Energy Business Publications, Singapore.
Club des Actions de Recherche sur les Ouvrages en Mer. (1993). Design guides for offshore structures, P. Le Tirant and C. Pérol, eds., Editions Technip, Paris.
Edwards, D. H., and Potts, D. M. (2004). “The bearing capacity of circular footing under ‘punch-through’ failure.” Proc., 9th Int. Symp. on Numerical Models in Geomechanics, Taylor & Francis, London, 493–498.
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.
Erbrich, C. T. (2005). “Australian frontiers—Spudcans on the edge.” Proc., 1st Int. Symp. on Frontiers in Offshore Geotechnics (ISFOG), Taylor & Francis, London, 49–74.
Handidjaja, P., Somehsa, P., and Manoj, M. (2004). “‘Swiss-cheese’—A method of degrading soil crust and minimizing risk to punch through problem on the installation of mobile offshore drilling unit (MODU).” Proc., 15th Southeast Asian Geotechnical Society Conf., South East Asian Geotechnical Society, Pathumthani, Thailand, 303–306.
Hossain, M. S. (2014). “Experimental investigation of spudcan penetration in multi-layer clays with interbedded sand layers.” Géotechnique, 64(4), 258–276.
Hossain, M. S., and Randolph, M. F. (2009a). “Effect of strain rate and strain softening 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.
Hossain, M. S., and Randolph, M. F. (2009c). “New mechanism-based design approach for spudcan foundations on stiff-over-soft clay.” Proc., Offshore Technology Conf., Offshore Technology Conference, Houston.
Hossain, M. S., and Randolph, M. F. (2010a). “Deep-penetrating spudcan foundations on layered clays: Centrifuge tests.” Géotechnique, 60(3), 157–170.
Hossain, M. S., and Randolph, M. F. (2010b). “Deep-penetrating spudcan foundations on layered clays: Numerical analysis.” Géotechnique, 60(3), 171–184.
Hossain, M. S., Randolph, M. F., and Saunier, Y. N. (2011). “Spudcan deep penetration in multi-layered fine-grained soils.” Int. J. Phys. Modell. Geotech., 11(3), 100–115.
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.
InSafeJIP. (2010). Improved guidelines for the prediction of geotechnical performance of spudcan foundations during installation and removal of jack-up units, RPS Energy, Abingdon, Oxfordshire, U.K.
ISO. (2011). “Petroleum and natural gas industries—Site specific assessment of mobile offshore units—Part 1: Jack-ups.” ISO 19905-1, Geneva.
Jack, R. L., Hoyle, M. J. R., Hunt, R. J., and Smith, N. P. (2007). “Jack-up accident statistics: Lots to learn!” Proc., 11th Int. Conf. on the Jack-up Platform: Design, Construction and Operation, London.
Jack, R. L., Hoyle, M. J. R., Smith, N. P., and Hunt, R. J. (2013). “Jack-up accident statistics—A further update.” Proc., 14th Int. Conf. on the Jack-up Platform: Design, Construction and Operation, City Univ. London, London.
Kostelnik, A. M., Guerra, M. D., Alford, J., Vazquez, J., and Zhong, J. (2007). “Jackup mobilization in hazardous soils.” SPE Drill. Complet., 22(1), 4–15.
Low, H. E., Randolph, M. F., DeJong, J. T., and Yafrate, N. J. (2008). “Variable rate full-flow penetration tests in intact and remoulded soil.” Proc., 3rd Int. Conf. on Geotechnical and Geophysical Site Characterization, Taylor & Francis, London, 1087–1092.
Lu, Q., Randolph, M. F., Hu, Y., and Bugarski, I. C. (2004). “A numerical study of cone penetration in clay.” Géotechnique, 54(4), 257–267.
Lunne, T., Berre, T., Andersen, K. H., Strandvik, S., and Sjursen, M. (2006). “Effects of sample disturbance and consolidation procedures on measured shear strength of soft marine Norwegian clays.” Can. Geotech. J., 43(7), 726–750.
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 Computer Methods and Advances in Geomechanics, Vol. 2, Balkema, Rotterdam, Netherlands, 1417–1428.
Maung, U. M., and Ahmad, C. K. M. (2000). “Swiss cheesing to bring in a jack-up rig at Anding location.” Proc., IADC/SPE Asia Pacific Drilling Technology, Society of Petroleum Engineers, Kuala Lumpur, Malaysia.
Menzies, D., and Lopez, C. R. (2011). “Four atypical jack-up rig foundation case histories.” Proc., 13th Int. Conf. on the Jack-up Platform: Design, Construction and Operation, City Univ. London, London.
Menzies, D., and Roper, R. (2008). “Comparison of jackup rig spudcan penetration methods in clay.” Proc., Offshore Technology Conf., Offshore Technology Conference, Houston.
Merifield, R. S., and Nguyen, V. Q. (2006). “Two- and three-dimensional bearing capacity solutions for footing on two-layered clays.” Geomech. Geoeng., 1(2), 151–162.
Meyerhof, G. G., and Chaplin, T. K. (1953). “The compression and bearing capacity of cohesive layers.” Br. J. Appl. Phys., 4(1), 20–26.
Qiu, G., and Grabe, J. (2011). “Explicit modelling of cone and strip footing penetration under drained and undrained conditions using a visco-hypoplastic model.” Geotechnik, 34(3), 205–217.
Qiu, G., and Grabe, J. (2012). “Numerical investigation of bearing capacity due to spudcan penetration in sand overlying clay.” Can. Geotech. J., 49(12), 1393–1407.
Qiu, G., and Henke, S. (2011). “Controlled installation of spudcan foundations on loose sand overlying weak clay.” Mar. Structures, 24(4), 528–550.
Randolph, M. F. (2004). “Characterisation of soft sediments for offshore applications (Keynote Lecture).” Proc., 2nd Int. Conf. on Site Characterization, Vol. 1, Millpress Science, Rotterdam, Netherlands, 209–231.
Randolph, M. F., Cassidy, M. J., Gourvenec, S., and Erbrich, C. J. (2005). “Challenges of offshore geotechnical engineering. State of the art paper.” Proc., Int. Conf. on Soil Mechanics and Foundation Engineering, International Society for Soil Mechanics and Geotechnical Engineering, London, 123–176.
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.
Thorne, C. P., Wang, C. X., and Carter, J. P. (2004). “Uplift capacity of rapidly loaded strip anchors in uniform strength clay.” Géotechnique, 54(8), 507–517.
Wang, C. X., and Carter, J. P. (2002). “Deep penetration of strip and circular footings into layered clays.” Int. J. Geomech., 205–232.
Wong, P. C., et al. (2012). “Foundation modeling and assessment in the new ISO standard 19905-1.” Proc., Offshore Technology Conf., Offshore Technology Conference, Houston.
Young, A. G., Remmes, B. D., and Meyer, B. J. (1984). “Foundation performance of offshore jack-up drilling rigs.” J. Geotech. Engrg., 841–859.
Zheng, J., Hossain, M. S., and Wang, D. (2013). “3D large deformation FE analysis of spudcan and cone penetration on three-layer clays.” Proc., 23rd Int. Offshore and Polar Engineering Conf., International Society of Offshore and Polar Engineers, Cupertino, CA, 453–460.
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.” Géotechnique, 59(2), 79–86.
Zhou, M., Hossain, M. S., Hu, Y., and Liu, H. (2012). “Behaviour of ball penetrometer in uniform single- and double-layer clays.” Géotechnique, 63(8), 682–694.
Information & Authors
Information
Published In
Copyright
© 2014 American Society of Civil Engineers.
History
Received: May 20, 2013
Accepted: Jul 28, 2014
Published online: Aug 28, 2014
Published in print: Dec 1, 2015
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.