Behavior of Suction Embedded Plate Anchors during Keying Process
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 138, Issue 2
Abstract
Suction embedded plate anchors (SEPLAs) allow for accurate positioning, thus providing an attractive alternative to traditional drag embedment anchors. This paper presents an analytical model for predicting the behavior of SEPLAs during the keying process, with a specific focus on predicting the loss of embedment depth as the anchor rotates from its initial vertical position to its target orientation perpendicular to the direction of loading. The soil is idealized as an incompressible, rigid-plastic material obeying an associated-flow rule. A generalized plastic limit analysis is employed to estimate the trajectories and corresponding capacities of SEPLAs under different loading conditions. The effects of soil resistance on the shank and anchor interaction with the anchor chain are also considered in the model. The SEPLA design commonly features a hinged flap; the effect of the flap is examined theoretically by comparing the solutions for the SEPLA with and without flap. Predicted solutions are shown in reasonably good agreement with some published numerical and experimental results, supporting the validity of the model.
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Acknowledgments
The authors would like to thank Bob Wilde of InterMoor, Inc., for his encouragement and helpful comments during the course of this project. The authors are also grateful to the SEPLA Joint Industry Project for providing the results of the centrifuge tests used to test this model. The first author is indebted to Geoscience Earth and Marine Services, Inc., for their financial support and for the use of their facilities during this work.
References
Andersen, K. H., Murff, J. D., and Randolph, M. F. (2003). “Deepwater anchor design practice-vertically loaded drag anchors.” Phase II Rep. to API/Deepstar JIP, Norwegian Geotechnical Institute, Norway/Offshore Technology Research Center, TX/Centre for Offshore Foundation Systems, Australia.
Bransby, M. F., and O’Neill, M. P. (1999). “Drag anchor fluke-soil interaction in clays.” Numerical Models in Geomechanics: Proc. of the 7th Int. Symp. (NUMOG VII), A.A. Balkema, Rotterdam, The Netherlands, 489–494.
Degenkamp, G., and Dutta, A. (1989). “Soil resistances to embedded anchor chain in soft clay.” J. Geotech. Eng., 115(10), 1420–1438.
Dove, P., Treu, H., and Wilde, B. (1998). “Suction embedded plate anchor (SEPLA): A new anchoring solution for ultra-deep water mooring.” Proc., D.O.T. 10th Int. Conf. and exhibition, Deep Offshore Technology, London.
Elkhatib, S., and Randolph, M. F. (2005). “The effect of interface friction on the performance of drag-in plate anchors.” Proc. Int. Symp. on Frontiers in Offshore Geotechnics (IS-FOG05), Taylor & Francis, London, 171–177.
Gaudin, C., O’Loughlin, C. D., Randolph, M. F., and Lowmass, A. C. (2006). “Influence of the installation process on the performance of suction embedded plate anchors.” Geotechnique, 56(6), 381–391.
Martin, C. M., and Randolph, M. F. (2001). “Applications 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, Taylor & Francis, Abingdon, England, 1417–1428.
Merifield, R. S., Lyamin, A. V., Sloan, S. W., and Yu, H. S. (2003). “Three-dimensional lower bound solutions for stability of plate anchors in clay.” J. Geotech. Geoenviron. Eng., 129(3), 243–253.
Merifield, R. S., Sloan, S. W., and Yu, H. S. (2001). “Stability of plate anchors in undrained clay.” Geotechnique, 51(2), 141–153.
Murff, J. D. (1994). “Limit analysis of multi-footing foundation systems.” Proc., 8th Int. Conf. on Computer Methods and Advances in Geomechanics, Taylor & Francis, Abingdon, England, 233–244.
Murff, J. D. et al. (2005). “Vertically loaded plate anchors for deepwater applications.” Proc. Int. Symp. on Frontiers in Offshore Geotechnics (IS-FOG05), Taylor & Francis, London, 31–48.
Neubecker, S. R., and Randolph, M. F. (1995). “Profile and frictional capacity of embedded anchor chains.” J. Geotech. Eng., 121(11), 797–803.
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.
Prager, W. (1959). An introduction to plasticity, Addison Wesley, Reading, MA.
Song, Z., and Hu, Y. (2005). “Vertical pullout behaviour of plate anchors in uniform clay.” Proc., Int. Symp. on Frontiers in Offshore Geotechnics, (IS-FOG05), Taylor & Francis, London, 205–211.
Song, Z., Hu, Y., O’Loughlin, C., and Randolph, M. F. (2009). “Loss in anchor embedment during plate anchor keying in clay.” J. Geotech. Geoenviron. Eng., 135(10), 1475–1485.
Song, Z., Hu, Y., and Randolph, M. F. (2005). “Pullout behaviour of inclined plate anchors inuniform clay.” Proc., 11th Int. Conf. on Computer Methods and Advances in Geomechanics, Taylor & Francis, London, 715–722.
Thorne, C. P. (1998). “Penetration and load capacity of marine drag anchors in soft clay.” J. Geotech. Geoenviron. Eng., 124(10), 945–953.
Vivatrat, V., Valent, P. J., and Ponterio, A. A. (1982). “The influence of chain friction on anchor pile design.” Proc., 14th Annual Offshore Technology Conf., Houston, 153–163.
Wang, D., Hu, Y., and Randolph, M. F. (2010). “Three-dimensional large deformation finite-element analysis of plate anchors in uniform clay.” J. Geotech. Geoenviron. Eng., 136(2), 355–365.
Wilde, B. (2005). “Program of centrifuge and field tests on the suction embedded plate anchor.” Rep. to SEPLA Joint Industry Project, Inter Moor, Houston.
Wilde, B., Treu, H., and Fulton, T. (2001). “Field testing of suction embedded plate anchors.” Proc., 11th Int. Offshore and Polar Engineering Conf., Int. Society of Offshore and Polar Engineers, Mountain View, CA, 544–551.
Yang, M., Murff, J. D., Aubeny, C. P., Lupulescu, C., Lee, C. H., and Gilbert, R. B. (2007). “Out of plane loading of plate anchors.” Phase I Rep. to ABS Consulting, Texas A&M Univ. and Univ. of Texas at Austin, Austin, TX.
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© 2012 American Society of Civil Engineers.
History
Received: Mar 16, 2010
Accepted: Jun 15, 2011
Published online: Jun 17, 2011
Published in print: Feb 1, 2012
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