Estimating Spudcan Penetration Resistance in Stiff-Soft-Stiff Clay
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 144, Issue 3
Abstract
The paper presents a new mechanism-based two-step approach for assessing spudcan penetration resistance in three-layer stiff-soft-stiff clay sediments. An alternative approach is also proposed, establishing a direct correlation between spudcan and cone penetration resistances. The approaches are developed based on the results from a parametric study through large-deformation finite-element analyses and validated against centrifuge test data and a case history. These can be taken as a “top-down” approach. The bearing capacities are evaluated at the seabed, at the depth of maximum bearing capacity in the first (stiff) layer, at the depth of triggering squeezing in the second (soft) layer, and at the second–third layer interface successively, followed by the estimation of the penetration resistance profile in the third (stiff) layer. For the mechanism-based approach, design formulae are also proposed for assessing the limiting cavity depth, variation of the soil plug height, and equivalent undrained shear strength of the second layer that accounts for the effect of the third layer. The depth of triggering squeezing in the second layer is estimated through an iterative approach to incorporate the effect of the soil plug trapped beneath the advancing spudcan, which leads to earlier squeezing. For the alternative approach, design correlations are established between cone tip and spudcan penetration resistances. A direct comparison between the estimated profiles using the proposed design approaches and the “bottom-up” approach recommended in the current international design standard confirms the benefit of using the former.
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Acknowledgments
The first author was the recipient of the University of Western Australia SIRF and UIS scholarships and the Australia-China Natural Gas Technology Partnership Fund top-up scholarship. The second author was an Australian Research Council (ARC) Discovery Early Career Researcher Award (DECRA) Fellow and was supported by the ARC Project DE140100903. The research presented here was undertaken with support from the Australian Research Council (ARC) through the ARC Linkage Project LP110100174. 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, through Centre of Excellence funding from the State Government of Western Australia and in partnership with The Lloyd’s Register Foundation. This support is gratefully acknowledged.
References
ABAQUS version 6.10 [Computer software]. Dassault Systèmes, Waltham, MA.
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 City, 45–51.
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, PetroMin, Jeddah, Saudi Arabia.
Edwards, D., Bienen, B., Pucker, T., and Henke, S. (2013). “Evaluation of the performance of a CPT-based correlation to predict spudcan penetrations using field data.” Proc., 14th Int. Conf.: The Jack-Up Plattform—Design, Construction and Operation, DNV.GL, City Univ. of London, London.
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, CRC Press, Boca Raton, FL, 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.
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. (2009). “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. (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.
Hossain, M., Zheng, J., Menzies, D., Meyer, L., and Randolph, M. (2014). “Spudcan penetration analysis for case histories in clay.” J. Geotech. Geoenviron. Eng., 04014034.
Houlsby, G. T., and Martin, C. T. (2003). “Undrained bearing capacity factors for conical footings on clay.” Géotechnique, 53(5), 513–520.
InSafeJIP. (2011). “Improved guidelines for the prediction of geotechnical performance of spudcan foundations during installation and removal of jack-up units.” RPS Energy, Abingdon, U.K.
ISO. (2012). “Petroleum and natural gas industries—Site specific assessment of mobile offshore units—Part 1: Jack-ups.” ISO 19905-1, Geneva.
Lunne, T., Robertson, P. K., and Powell, J. M. (1997). Cone penetration testing in geotechnical practice, Blackie Academic and Professional, London.
Ma, H., Zhou, M., Hu, Y., and Hossain, M. S. (2015). “Interpretation of layer boundaries and shear strengths for soft-stiff-soft clays using CPT data: LDFE analyses.” J. Geotech. Geoenviron. Eng., 04015055.
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, DNV.GL, City Univ. of London, London.
Menzies, D., and Roper, R. (2008). “Comparison of jackup rig spudcan penetration methods in clay.” Proc., Offshore Technology Conf. OTC19545, Offshore Technology Conference, Houston.
Meyerhof, G. G., and Chaplin, T. K. (1953). “The compression and bearing capacity of cohesive layers.” Br. J. Appl. Phys., 4(1), 20–26.
Pucker, T., Bienen, B., and Henke, S. (2013). “CPT based prediction of foundation penetration in siliceous sand.” Appl. Ocean Res., 41, 9–18.
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.” Marine Struct., 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.
Skempton, A. W. (1951). “The bearing capacity of clays.” Proc., Building Research Congress, Vol. 1, London, 180–189.
Song, Z., Hu, Y., and Randolph, M. F. (2008). “Numerical simulation of vertical pullout of plate anchors in clay.” J. Geotech. Geoenviron. Eng., 866–875.
Tho, K. K., Chen, Z., Leung, C. F., and Chow, Y. K. (2013). “Pullout behaviour of plate anchor in clay with linearly increasing strength.” Can. Geotech. J., 51(1), 92–102.
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.
Walker, J., and Yu, H. S. (2010). “Analysis of the cone penetration test in layered clay.” Géotechnique, 60(12), 939–948.
Watson, P. G., Suemasa, N., and Randolph, M. F. (2000). “Evaluating undrained shear strength using the vane shear apparatus.” Proc., 10th Int. Conf. on Offshore and Polar Engineering, Vol. 2, International Society of Offshore and Polar Engineers, Mountain View, CA, 485–493.
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.
Zheng, J., Hossain, M. S., and Wang, D. (2014a). “Large deformation finite element analysis of cone penetration on strain softening, rate dependent non-homogeneous clay.” Proc., 3rd Int. Symp. on Cone Penetration Testing, International Society for Soil Mechanics and Geotechnical Engineering, London.
Zheng, J., Hossain, M., and Wang, D. (2014b). “Numerical modeling of spudcan deep penetration in three-layer clays.” Int. J. Geomech., 04014089.
Zheng, J., Hossain, M. S., and Wang, D. (2015a). “CPT based direct design approach for spudcan penetration in non-uniform clay with an interbedded stiff layer.” Proc., 14th Int. Conf. on Computer Methods and Recent Advances in Geomechanics (IACMAG), Kyoto, Japan, 895–900.
Zheng, J., Hossain, M. S., and Wang, D. (2015b). “New design approach for spudcan penetration in nonuniform clay with an interbedded stiff layer.” J. Geotech. Geoenviron. Eng., 04015003.
Zhou, H., and Randolph, M. F. (2009). “Resistance of full-flow penetrometers in rate-dependent and strain-softening clay.” Géotechnique, 59(2), 79–86.
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Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 144 • Issue 3 • March 2018
Copyright
©2018 American Society of Civil Engineers.
History
Received: Jun 2, 2015
Accepted: Jul 28, 2017
Published online: Jan 3, 2018
Published in print: Mar 1, 2018
Discussion open until: Jun 3, 2018
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