Keying Process of the OmniMax Anchor Shallowly Embedded in Undrained Normally Consolidated Clay
Publication: Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 144, Issue 4
Abstract
The OmniMax anchor is an efficient anchoring foundation due to its dynamic installation and diving property. When subjected to pullout loading, the anchor is keyed to a new orientation and position to provide holding capacity. However, the trajectory and capacity mobilization of the OmniMax anchor during its keying are still unclear, especially for anchors with shallow embedment depth. The present study investigated the keying process of the OmniMax anchor by using a plasticity model. The anchor yield envelope was established based on a shallowly embedded OmniMax anchor with a tip embedment depth of 1.5 times the anchor length. A series of parametric studies were subsequently carried out to investigate the effects of the soil strength gradient, the padeye offset and padeye eccentricity, the pullout angle at the mudline, and the chain parameters on anchor trajectory and capacity mobilization. The anchor ultimate embedment depth and, hence, the ultimate capacity in the final keying stage were discussed. To keep efficient diving property and high capacity simultaneously, it is recommended that the padeye offset angle should range from 15° to 25°, and the pullout angle at the mudline should be no more than 30°.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
This research was supported by the National Natural Science Foundation of China (51479027, 51539008), the Fundamental Research Funds for the Central Universities (DUT18ZD203) and the National Key Research and Development Program of China (2016YFE0200100). These supports are gratefully acknowledged.
References
AFENA [Computer software]. Centre for Geotechnical Research, Univ. of Sydney, Sydney, Australia.
Bransby, M. F., and O'Neill, M. (1999). “Drag anchor fluke soil interaction in clays.” Proc., 7th Int. Symp. On Numerical Models in Geomechanics – NUMOG VII, Balkema, Rotterdam, The Netherlands, 489–494.
Bransby, M. F., and Randolph, M. F. (1998). “Combined loading of skirted foundations.” Géotechnique, 48(5), 637–655.
Cassidy, M. J., Gaudin, C., Randolph, M. F., Wong, P. C., and Tian, Y. (2012). “A plasticity model to assess the keying of plate anchors.” Géotechnique, 62(9), 825–836.
Elkhatib, S. (2006). “The behaviour of drag-in plate anchors in soft cohesive soils.” Ph.D. thesis, Univ. of Western Australia, Western Australia, Australia.
Frankenmolen, S. F., White, D. J., and O'Loughlin, C. D. (2016). “Chain-soil interaction in carbonate sand.” Proc., 48th Offshore Technology Conf., OTC-27102-MS, Society of Petroleum Engineering, Houston.
Gaudin, C., O'Loughlin, C. D., Hossain, M. S., and Zimmerman, E. H. (2013). “The performance of dynamically embedded anchors in calcareous silt.” ASME 2013 32nd Int. Conf. on Ocean, Offshore and Arctic Engineering, Ocean, Offshore and Arctic Engineering Division of ASME, New York.
Han, C., and Liu, J. (2017). “A modified method to estimate chain inverse catenary profile in clay based on chain equation and chain yield envelope.” Appl. Ocean Res., 68, 142–153.
Hossain, M. S., Hu, Y., Randolph, M. F., and White, D. J. (2005). “Limiting cavity depth for spudcan foundations penetrating clay.” Géotechnique, 55(9), 679–690.
Hu, Y., and Randolph, M. F. (1998). “H-adaptive FE analysis of elasto-plastic non-homogeneous soil with large deformation.” Comput. Geotech., 23(1–2), 61–83.
Kim, Y. H., and Hossain, M. S. (2015). “Dynamic installation of OMNI-Max anchors in clay: Numerical analysis.” Géotechnique, 65(12), 1029–1037.
Kim, Y. H., and Hossain, M. S. (2017). “Dynamic installation, keying and diving of OMNI-Max anchors in clay.” Géotechnique, 67(1), 78–85.
Liu, H., Xu, K., and Zhao, Y. (2016a). “Numerical investigation on the penetration of gravity installed anchors by a coupled Eulerian–Lagrangian approach.” Appl. Ocean Res., 60, 94–108.
Liu, J., Han, C., and Yu, L. (2018). “Experimental investigation of the keying process of OMNI-Max anchor.” Mar. Georesour. Geotechnol..
Liu, J., Lu, L., and Hu, Y. (2016b). “Keying behavior of gravity installed plate anchor in clay.” Ocean Eng., 114(1), 10–24.
Liu, J., Lu, L. H., and Yu, L. (2014). “Large deformation finite element analysis of gravity installed anchors in clay.” Proce., ASME 33rd Int. Conf. on Ocean, Offshore and Arctic Engineering, ASME, New York, Paper OMAE2014-24347.
Liu, J., Lu, L., and Yu, L. (2017). “Keying behavior of suction embedded plate anchors with flap in clay.” Ocean Eng, 131, 231–243.
Lowmass, A. C. (2006). “Installation and keying of follower embedded plate anchors.” MEng thesis, Univ. of Western Australia, Western Australia, Australia.
Merifield, R. S., Sloan, S. W., and Yu, H. S. (2001). “Stability of plate anchors in undrained clay.” Géotechnique, 51(2), 141–154.
Murff, J. D. (1994). “Limit analysis of multi-footing foundation systems.” Proc., 8th Int. Conf. on Computer Method and Advances in Geomechanics, Advances in Geomechanics, Abingdon.
Neubecker, S. R., and Randolph, M. F. (1995). “Profile and frictional capacity of embedded anchor chains.” J. Geotech. Eng., 797–803.
Nouri, H., Biscontin, G., and Aubeny, C. P. (2017). “Numerical prediction of undrained response of plate anchors under combined translation and torsion.” Comput. Geotech., 81, 39–48.
O'Beirne, C., O'Loughlin, C. D., and Gaudin, C. (2015). “Soil response in the wake of dynamically installed projectiles.” Geotech. Lett., 5, 153–160.
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.
Shelton, J. T. (2007). “OMNI-MaxTM anchor development and technology.” Proc., Oceans Conf., IEEE, New York, pp. 1–10.
Tian, Y., Randolph, M. F., and Cassidy, M. J. (2015). “Analytical solution for ultimate embedment depth and potential holding capacity of plate anchors.” Géotechnique, 65(6), 517–530.
Wei, Q., Cassidy, M. J., Tian, Y., and Gaudin, C. (2015a). “Incorporating shank resistance into prediction of the keying behavior of suction embedded plate anchors.” J. Geotech. Geoenviron. Eng., 04014080.
Wei, Q., Tian, Y., Cassidy, M. J., Gaudin, C., and O'Loughlin, C. D. (2015b). “Behaviour of OMNI-Max anchors under chain loading.” Proc., Int. Symp. on Frontiers in Offshore Geotechnics, CRC Press, London.
Wu, X., Chow, Y. K., and Leung, C. F. (2017). “Behavior of drag anchor in clay with linearly increasing shear strength under unidirectional and combined loading.” Appl. Ocean Res., 63, 142–156.
Yang, M., Aubeny, C. P., and Murff, J. D. (2012). “Behavior of suction embedded plate anchors during keying process.” J. Geotech. Geoenviron. Eng., 174–183.
Yu, L., Liu, J., Kong, X., and Hu, Y. (2011). “Numerical study on plate anchor stability in clay.” Géotechnique, 61(3), 235–246.
Yu, S. B., Hambleton, J. P., and Sloan, S. W. (2015). “Undrained uplift capacity of deeply embedded strip anchors in non-uniform soil.” Comput. Geotech., 70, 41–49.
Zhang, Y., Bienen, B., Cassidy, M. J., and Gourvenec, S. (2012). “Undrained bearing capacity of deeply buried flat circular footings under general loading.” J. Geotech. Geoenviron. Eng., 385–397.
Zhao, Y., Liu, H., and Li, P. (2016). “An efficient approach to incorporate anchor line effects into the coupled Eulerian-Lagrangian analysis of comprehensive anchor behaviors.” Appl. Ocean Res., 59, 201–215.
Zimmerman, E. H., Smith, M. W., and Shelton, J. T. (2009). “Efficient gravity installed anchor for deepwater mooring.” Proc., 41th Offshore Technology conf., Society of Petroleum Engineering, Houston.
Information & Authors
Information
Published In
Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 144 • Issue 4 • July 2018
Copyright
© 2018 American Society of Civil Engineers.
History
Received: Jul 27, 2017
Accepted: Jan 11, 2018
Published online: Apr 27, 2018
Published in print: Jul 1, 2018
Discussion open until: Sep 27, 2018
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.