Installation and Removal Records of Field Trials for Two Mooring Dolphin Platforms with Three Suction Caissons
Publication: Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 139, Issue 6
Abstract
In 1999, two mooring dolphin platforms (MDP1 and MDP2), each with three suction caissons, were installed in the JZ9–3 field of the Bohai Sea of China. Before installation, penetration and retrieval tests for MDP1 were conducted near the design location site. In 2006, after being in service for 7 years, partial removal and repenetration prototype trials were performed for MDP2. The MDP1 platform has the same geometric structure and weight as MDP2, in which each suction caisson is 6 m in diameter and 9 m in height. Typical soil profiles at the site mainly consist of organic silt, silty clay, and clay. Records from the transducers were relevant to the installation and retrieval of the suction caissons, which were performed by controlling the pump discharge into/out of the caissons. The results show that skin friction decreases because of the seepage effect that occurs after applying the suction pressure inside the caisson. However, clayey or silty soils with low permeability required more time and suction to create a seepage flow to lower resistance in the penetration or removal phases. The setup effect caused by suction significantly increases the skin friction resistance by 62–84%, and the pump-out pressure equals 1.79–2.04 times the pump-in suction after 7 years. The on-site data are valuable for further study on the design and construction of platforms with suction caissons, especially regarding external skin friction.
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Acknowledgments
The authors acknowledge support from the National Natural Science Foundation of China (Grant No. 51109160), the National High Technology Research and Development Program of China (863 Program) (Grant No. 2012AA051705), and the International S&T Cooperation Program of China (Grant No. 2012DFA70490).
References
Andersen, K. H., et al. (2005). “Suction anchors for deepwater applications.” Proc., Int. Symp. Frontiers in Offshore Geotechnics (ISFOG), Taylor & Francis Group, London, 3–30.
Andersen, K. H., and Jostad, H. P. (2002). “Shear strength along outside wall of suction anchors in clay after installation.” Proc., 12th Int. Offshore and Polar Engineering Conf., ISOPE, San Francisco.
Andersen, K. H., and Jostad, H. P. (2004). “Shear strength along inside of suction anchor skirt wall in clay.” Offshore Technology Conf., OTC 16844, OTC, Houston.
Andersen, K. H., Jostad, H. P., and Dyvik, R. (2008). “Penetration resistance of offshore skirted foundations and anchors in dense sand.” J. Geotech. Geoenviron. Eng., 134(1), 106–116.
Cao, J., Phillips, R., Popescu, R., Al-Khafaji, Z., and Audibert, J. M. E. (2002). “Penetration resistance of suction caissons in clay.” Proc., 12th Int. Offshore and Polar Engineering Conf., ISOPE, San Francisco, 800–806.
Chen, W., Zhou, H., and Randolph, M. F. (2009). “Effect of installation method on external shaft friction of caissons in soft clay.” J. Geotech. Geoenviron. Eng., 135(5), 605–615.
Colliat, J. L., Boisard, P., Sparrevik, P., and Gramet, J. C. (1998). “Design and installation of suction anchor piles at soft clay site.” J. Waterway, Port, Coastal, Ocean Eng., 124(4), 179–188.
Colliat, J. L., and Colliard, D. (2010). “Set-up of suction piles in deepwater Gulf of Guinea clays.” Frontiers in Offshore Geotechnics II: Proc., 2nd Int. Symp. on Frontiers in Offshore Geotechnics, Taylor & Francis Group, London.
Colliat, J. L., Dendani, H., and Schroeder, K. (2007). “Installation of suction piles at deepwater sites in Angola.” Proc., Int. Conf. on Offshore Site Investigation and Geotechnics, London, OSIG-07-413, Society of Underwater Technology, London.
Dendani, H., and Colliat, J. L. (2002). “Girassol: Design analysis and installation of suction anchors.” Offshore Technology Conf., OTC 14209, OTC, Houston.
Ding, H., Qi, L., and Xu, J. (2001). “Bucket foundation platforms installed in shallow and ice-drifting area.” J. Cold Reg. Eng., 15(4), 211–218.
Dupal, K., Von Eberstein, B., Loeb, D., Xu, H., Grant, J., and Bergeron, B. (2000). “Shell’s experience with deepwater mooring systems for MODU.” Proc., Int. Conf. on Deep Offshore Technology, DOT, New Orleans.
Ehlers, C. J., Young, A. G., and Chen, J. W. (2004). “Technology assessment of deepwater anchors.” Offshore Technology Conf., OTC 16840, OTC, Houston.
Eltaher, A., Rajapaksa, Y., and Chang, K. T. (2003). “Industry trends for design of anchoring systems for deepwater offshore structures.” Offshore Technology Conf., OTC 15265, OTC, Houston.
Erbrich, C. T., and Tjelta, T. I. (1999). “Installation of bucket foundations and suction caissons in sand: Geotechnical performance.” Offshore Technology Conf., OTC 10990, OTC, Houston.
Hossain, M. S., Lehane, B. M., Hu, Y., and Gao, Y. (2012). “Soil flow mechanisms around and between stiffeners of caissons during installation in clay.” Can. Geotech. J., 49(4), 442–459.
Houlsby, G. T., and Byrne, B. W. (2005). “Design procedures for installation of suction caissons in clay and other materials.” Geotech. Eng., 158(2), 75–82.
Houlsby, G. T., Kelly, R. B., Huxtable, J., and Byrne, B. W. (2005). “Field trials of suction caissons in clay for offshore wind turbine foundations.” Geotechnique, 55(4), 287–296.
Jeanjean, P., Znidarcic, D., Phillips, R., Ko, H. Y., Pfister, S., and Schroeder, K. (2006). “Centrifuge testing on suction anchors: Doublewall, stiff clays, and layered soil profile.” Offshore Technology Conf., OTC 18007, OTC, Houston.
Mana, D. S. K., Gourvenec, S. M., Randolph, M. F., and Hossain, M. S. (2012). “Failure mechanisms of skirted foundations in uplift and compression.” Int. J. Phys. Modell. Geotech., 12(2), 47–62.
Senders, M., and Randolph, M. F. (2009). “CPT-based method for the installation of suction caissons in sand.” J. Geotech. Geoenviron. Eng., 135(1), 14–25.
Tran, M. N., Randolph, M. F., and Airey, D. W. (2007). “Installation of suction caissons in sand with silt layers.” J. Geotech. Geoenviron. Eng., 133(10), 1183–1191.
Vásquez, L. F. G., Maniar, D. R., and Tassoulas, J. L. (2010). “Installation and axial pullout of suction caissons: Numerical modeling.” J. Geotech. Geoenviron. Eng., 136(8), 1137–1147.
Information & Authors
Information
Published In
Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 139 • Issue 6 • November 2013
Pages: 502 - 517
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Jul 25, 2012
Published online: Apr 30, 2013
Accepted: May 20, 2013
Published in print: Nov 1, 2013
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