Effects of Consolidation under a Penetrating Footing in Carbonate Silty Clay
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 141, Issue 9
Abstract
The effects of consolidation under a footing are generally viewed as beneficial due to the resulting increased capacity. Consolidation may also be actively sought because it minimizes footing embedment, which can be critical for the installation of mobile offshore jack-ups because available leg length is limited. However, it can also set the platform footing up to subsequently punch through the strengthened zone, with potentially serious consequences. The problem is complex due to the three-dimensional nature of consolidation. Further, footing penetration leaves the soil above heavily remolded and generates large excess pore pressures below, such that the soil state even prior to consolidation is significantly altered from its in situ conditions. This study has taken an experimental approach to investigate the effects of consolidation around a footing penetrating into carbonate silty clay and, following detailed discussion of the response, offers a framework to predict the changes to the load-penetration curve.
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 an Australian Research Council (ARC) Postdoctoral Fellowship (DP110101603) and the third author is the recipient of an ARC Laureate Fellowship (FL130100059). This work forms part of the activities of the Centre for Offshore Foundation Systems (COFS), currently supported as a node of the ARC Centre of Excellence for Geotechnical Science and Engineering and as a Centre of Excellence by the Lloyd’s Register Foundation. Lloyd’s Register Foundation invests in science, engineering, and technology for public benefit, worldwide. This support is gratefully acknowledged.
References
Barbosa-Cruz, E. R. (2007). “Partial consolidation and breakthrough of shallow foundations in soft soil.” Ph.D. thesis, Univ. of Western Australia, Perth, Australia.
Bienen, B., and Cassidy, M. J. (2013). “Set-up and resulting punch-through risk of jack-up spudcans during installation.” J. Geotech. Geoenviron. Eng., 2048–2059.
Bienen, B., Gaudin, C., and Cassidy, M. J. (2009). “The influence of pull-out load on the efficiency of jetting during spudcan extraction.” Appl. Ocean Res., 31(3), 202–211.
Brennan, R., et al. (2006). “Installing jackups in punch-through sensitive clays.” Proc., Offshore Technology Conf. (OTC), Society of Petroleum Engineers, Richardson, TX.
Cassidy, M. J. (2012). “Experimental observations of the penetration of spudcan footings in silt.” Géotechnique, 62(8), 727–732.
Chung, S. F., Randolph, M. F., and Schneider, J. A. (2006). “Effect of penetration rate on penetration resistance in clay.” J. Geotech. Geoenviron. Eng., 1188–1196.
Craig, W. H., and Chua, K. (1990). “Deep penetration of spudcan foundations on sand and clay.” Géotechnique, 40(4), 541–556.
Dijkstra, J., Gaudin, C., and White, D. J. (2013). “Comparison of failure modes below footings on carbonate and silica sands.” Int. J. Phys. Modell. Geotech., 13(1), 1–12.
Erbrich, C., and Hefer, P. (2002). “Installation of the Laminaria suction piles—A case history.” Offshore Technology Conf., Society of Petroleum Engineers, Richardson, TX.
Erbrich, C. T. (2005). “Australian frontiers—Spudcans on the edge.” Proc., Int. Symp. on Frontiers in Offshore Geotechnics (ISFOG), Taylor & Francis, London, 49–74.
Finnie, I. M. S. (1993). “Performance of shallow foundations in calcareous soil.” Ph.D. thesis, Univ. of Western Australia, Perth, Australia.
Garnier, J., et al. (2007). “Catalogue of scaling laws and similitude questions in centrifuge modelling.” Int. J. Phys. Modell. Geotech., 7(3), 1–24.
Gaudin, C., Bienen, B., and Cassidy, M. J. (2011a). “Investigation of the potential of bottom water jetting to ease spudcan extraction in soft clay.” Géotechnique, 61(12), 1043–1054.
Gaudin, C., Cassidy, M. J., Bienen, B., and Hossain, M. S. (2011b). “Recent contributions of geotechnical centrifuge modelling to the understanding of jack-up spudcan behaviour.” Ocean Eng., 38(7), 900–914.
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.
Hu, P., Stanier, S., Cassidy, M. J., and Wang, D. (2014). “Predicting the peak resistance of a spudcan penetrating sand overlying clay.” J. Geotech. Geoenviron. Eng., 140(2), 04013009.
Hunt, R. (2008). “Achieving operational excellence for jack-up rig deployments– how shall we get there?” Proc., 2nd Jack-Up Asia Conf. and Exhibition, PetroMin, Singapore.
ISO (International Organization for Standardization). (2012). “Petroleum and natural gas industries– Site-specific assessment of mobile offshore units—Part 1: Jack-ups.” Geneva.
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, Design, Construction and Operation, City Univ., London.
Lee, K. K., Cassidy, M. J., and Randolph, M. F. (2013a). “Bearing capacity on sand overlying clay soils: Experimental and finite-element investigation of potential punch-through failure.” Géotechnique, 63(15), 1271–1284.
Lee, K. K., Randolph, M. F., and Cassidy, M. J. (2013b). “Bearing capacity on sand overlying clay soils: A simplified conceptual model.” Géotechnique, 63(15), 1285–1297.
Osborne, J. J., Pelley, D., Nelson, C., and Hunt, R. (2006). “Unpredicted jack-up foundation performance.” Proc., Jack-Up Asia Conf. and Exhibition, PetroMin, Singapore.
Purwana, O. A., Leung, C. F., Chow, Y. K., and Foo, K. S. (2005). “Influence of base suction on extraction of jack-up spudcans.” Géotechnique, 55(10), 741–753.
Purwana, O. A., Quah, M., Foo, K. S., Nowak, S. and Handidjaja, P. (2009). “Leg extraction/pullout resistance: Theoretical and practical perspectives.” Proc., 12th Int. Conf. on the Jack-Up Platform: Design, Construction and Operation, City Univ., London.
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.
Randolph, M. F., Hefer, P. A., Geise, J. M., and Watson, P. G. (1998a). “Improved seabed strength profiling using T-bar penetrometer.” Proc., Int. Conf. on Offshore Site Investigation and Foundation Behaviour—“New Frontiers”, Society for Underwater Technology, London, 221–235.
Randolph, M. F., Jewell, R. J., Stone, K. J. L., and Brown, T. A. (1991). “Establishing a new centrifuge facility.” Proc., Int. Conf. on Centrifuge Modelling, Centrifuge 91, 3–9.
Randolph, M. F., O’Neill, M. P., Stewart, D. P., and Erbrich, C. (1998b). “Performance of suction anchors in fine-grained calcareous soils.” Offshore Technology Conf., Society of Petroleum Engineers, Richardson, TX.
Stanier, S., Ragni, R., Bienen, B., and Cassidy, M. J. (2014). “Observing the effects of sustained loading on spudcan footings in clay.” Géotechnique, 64(11), 918–926.
Stanier, S. A., and White, D. J. (2013). “An improved image based deformation measurement system for the centrifuge environment.” Geotech. Test. J., 36(6), 915–927.
Stewart, D. P., Boyle, R. S., and Randolph, M. F. (1998). “Experience with a new drum centrifuge.” Proc., Int. Conf. Centrifuge 98, 35–40.
Teh, K. L., Leung, C. F., Chow, Y. K., and Cassidy, M. J. (2010). “Centrifuge model study of spudcan penetration in sand overlying clay.” Géotechnique, 60(11), 825-842.
Yamamoto, N., Randolph, M. F., and Einav, I. (2008). “Simple formulas for the response of shallow foundations on compressible sands.” Int. J. Geomech., 230–239.
Yu, L., Hu, Y., Liu, A., Randolph, M. F., and Kong, X. (2012). “Numerical study of spudcan penetration in loose sand overlying clay.” Comput. Geotech., 46, 1–12.
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., Cassidy, M. J., and Bienen, B. (2014). “A plasticity model for spudcan foundations in soft clay.” Can. Geotech. J., 51(6), 629–646.
Information & Authors
Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 141 • Issue 9 • September 2015
Copyright
© 2015 American Society of Civil Engineers.
History
Received: May 27, 2014
Accepted: Mar 24, 2015
Published online: May 12, 2015
Published in print: Sep 1, 2015
Discussion open until: Oct 12, 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.