Innovative Booster for Dynamic Installation of OMNI-Max Anchor in Clay: Numerical Modeling
Publication: Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 148, Issue 1
Abstract
An innovative booster is proposed with the aim of increasing the final penetration depth of the OMNI-Max anchor in the clayey seabed with high strength gradient. The booster is attached to the tail of the OMNI-Max anchor, which is beneficial in improving both gravitational and kinetic energies of the hybrid anchor (i.e., booster + OMNI-Max anchor) during installation and can be retrieved after dynamic installation. The present study carried out two categories of large deformation numerical analyses to simulate the dynamic penetration processes of OMNI-Max anchors and hybrid anchors in normally consolidated and lightly overconsolidated clay. The coupled Eulerian–Lagrangian (CEL) approach was used to investigate the effects of impact velocity, booster weight, and soil strength characteristics (including the strain-rate behavior, the strain-softening behavior, and the undrained shear strength) on the final penetration depth of the anchor. Due to the limitations of the CEL approach in simulating the adhesion friction at the anchor–soil interface, a thin layer region method coupled in the computational fluid dynamics (CFD) approach was used to investigate the effect of the friction coefficient at the anchor–soil interface on the final penetration depth of the anchor. Based on numerical simulation results, a comprehensive prediction model based on the anchor total energy was established to rapidly predict the final penetration depth of the OMNI-Max anchor and the hybrid anchor by considering the strain-rate effect, strain-softening effect, and friction coefficient at the anchor–soil interface.
Get full access to this article
View all available purchase options and get full access to this article.
Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.
Acknowledgments
This research was supported by the National Natural Science Foundation of China (Grant Nos. 51890915 and 51979035); and the Dalian Science and Technology Innovation Fund (Grant No. 2020JJ26GX021). These supports are gratefully acknowledged.
Notation
The following symbols are used in this paper:
- AF
- frontal area of the OMNI-Max anchor;
- As
- side area of the OMNI-Max anchor;
- DA
- ring diameter of the loading arm;
- DB
- shaft diameter of the booster;
- Deff
- anchor effective diameter;
- Etotal
- anchor total energy;
- hA
- length of the OMNI-Max anchor;
- hA1 and hA2
- lengths of top and tip flukes of the OMNI-Max anchor;
- hB
- length of the booster;
- k
- soil strength gradient;
- ke
- equivalent strength gradient;
- keff
- equivalent strength gradient considering strain-rate and strain-softening effects;
- mA
- mass of the OMNI-Max anchor;
- mB
- mass of the booster;
- St
- soil sensitivity;
- su
- undrained shear strength;
- sum
- undrained shear strength at the mudline;
- su,ref
- undrained shear strength at the reference shear strain rate;
- tA
- thickness of the fluke;
- v
- instantaneous penetration velocity;
- vi
- impact velocity;
- W′
- submerged weight of the anchor in water;
- wA
- width of the fluke;
- z
- instantaneous penetration depth of the anchor;
- ze
- final penetration depth of the anchor;
- ze,base
- final penetration depth of the base case;
- α
- friction coefficient at the anchor–soil interface;
- β
- strain-rate parameter (shear-thinning index);
- shear strain rate;
- reference shear strain rate;
- γs
- unit weight of the soil;
- submerged unit weight of the soil;
- δrem
- remolded strength ratio;
- δrem,cyc
- remolded strength ratio from cyclic tests;
- ξ
- accumulated plastic shear strain;
- ξa
- average accumulated plastic shear strain;
- ξT-bar
- accumulated plastic shear strain during the first penetration of T-bar;
- ξ95
- accumulated plastic shear strain required for 95% remolding; and
- ρs
- density of the soil.
References
Abelev, A., and P. Valent. 2013. “Strain-rate dependence of strength of the Gulf of Mexico soft sediments.” IEEE J. Ocean. Eng. 38 (1): 25–31. https://doi.org/10.1109/JOE.2012.2208293.
Benson, D. J. 1992. “Computational methods in Lagrangian and Eulerian hydrocodes.” Comput. Methods Appl. Mech. Eng. 99 (2–3): 235–394. https://doi.org/10.1016/0045-7825(92)90042-I.
Biscontin, G., and J. M. Pestana. 2001. “Influence of peripheral velocity on vane shear strength of an artificial clay.” Geotech. Test. J. 24 (4): 423–429. https://doi.org/10.1520/GTJ11140J.
Chow, S. H., C. D. O'Loughlin, Z. Zhou, D. J. White, and M. F. Randolph. 2020. “Penetrometer testing in a calcareous silt to explore changes in soil strength.” Geotechnique 70 (12): 1160–1173. https://doi.org/10.1680/jgeot.19.P.069.
Dassault Systémes. 2014. Abaqus analysis: User’s manual. Providence, RI: Dassault Systémes.
Dutta, S., and B. Hawlader. 2019. “Pipeline–soil–water interaction modelling for submarine landslide impact on suspended offshore pipelines.” Géotechnique 69 (1): 29–41. https://doi.org/10.1680/jgeot.17.P.084.
Einav, I., and M. F. Randolph. 2005. “Combining upper bound and strain path methods for evaluating penetration resistance.” Int. J. Numer. Methods Eng. 63 (14): 1991–2016. https://doi.org/10.1002/nme.1350.
Gaudin, C., C. D. O'Loughlin, M. S. Hossain, and E. H. Zimmerman. 2013. “The performance of dynamically embedded anchors in calcareous silt.” In ASME 2013 32nd Int. Conf. on Ocean, Offshore and Arctic Engineering. Paper No. OMAE2013-10115. New York: ASME.
Han, C., J. Liu, Y. Zhang, and W. Zhao. 2019. “An innovative booster for dynamic installation of OMNI-Max anchors in clay: Physical modeling.” Ocean Eng. 171: 345–360. https://doi.org/10.1016/j.oceaneng.2018.10.029.
Hawlader, B., S. Dutta, A. Fouzder, and A. Zakeri. 2015. “Penetration of steel catenary riser in soft clay seabed: Finite-element and finite-volume methods.” Int. J. Geomech. 15 (6): 04015008. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000474.
Hu, Y., and M. F. Randolph. 1998. “H-adaptive FE analysis of elasto-plastic non-homogeneous soil with large deformation.” Comput. Geotech. 23: 61–83. https://doi.org/10.1016/S0266-352X(98)00012-3.
Kim, Y. H., and M. S. Hossain. 2015. “Dynamic installation of OMNI-Max anchors in clay: Numerical analysis.” Géotechnique 65 (12): 1029–1037. https://doi.org/10.1680/jgeot.15.T.008.
Kim, Y. H., and M. S. Hossain. 2017. “Dynamic installation, keying and diving of OMNI-Max anchors in clay.” Géotechnique 67 (1): 78–85. https://doi.org/10.1680/jgeot.16.T.008.
Kim, Y. H., M. S. Hossain, D. Wang, and M. F. Randolph. 2015. “Numerical investigation of dynamic installation of torpedo anchors in clay.” Ocean Eng. 108: 820–832. https://doi.org/10.1016/j.oceaneng.2015.08.033.
Lehane, B. M., C. D. O’Loughlin, C. Gaudin, and M. F. Randolph. 2009. “Rate effects on penetrometer resistance in kaolin.” Géotechnique 59 (1): 41–52. https://doi.org/10.1680/geot.2007.00072.
Lieng, J. T., F. Hove, and T. I. Tjelta. 1999. “Deep penetrating anchor: Subseabed deepwater anchor concept for floaters and other installations.” In Proc., 9th Int. Offshore and Polar Engineering Conf., 613–619. Cupertino, CA: International Society of Offshore and Polar Engineers.
Liu, H., K. Xu, and Y. Zhao. 2016. “Numerical investigation on the penetration of gravity installed anchors by a coupled Eulerian–Lagrangian approach.” Appl. Ocean Res. 60: 94–108. https://doi.org/10.1016/j.apor.2016.09.002.
Liu, J., X. Chen, C. Han, and X. Wang. 2019a. “Estimation of intact undrained shear strength of clay using full-flow penetrometers.” Comput. Geotech. 115: 103161. https://doi.org/10.1016/j.compgeo.2019.103161.
Liu, J., C. Han, Y. Ma, Z. Wang, and Y. Hu. 2018a. “Experimental investigations on hydrodynamic characteristics of OMNI-Max anchor with a booster.” Ocean Eng. 158: 38–53. https://doi.org/10.1016/j.oceaneng.2018.03.074.
Liu, J., C. Han, Y. Zhang, Y. Ma, and Y. Hu. 2018b. “An innovative concept of booster for OMNI-Max anchor.” Appl. Ocean Res. 76: 184–198. https://doi.org/10.1016/j.apor.2018.05.007.
Liu, J., Y. Ma, and C. Han. 2019b. “CFD analysis on directional stability and terminal velocity of OMNI-Max anchor with a booster.” Ocean Eng. 171: 311–323. https://doi.org/10.1016/j.oceaneng.2018.10.053.
Liu, J., and Y. Zhang. 2017. “Numerical simulation on the dynamic installation of the gravity installed plate anchor in clay using a fluid dynamic approach.” In Proc., 36th Int. Conf. on Ocean, Offshore and Arctic Engineering. New York: ASME.
Low, H. E., T. Lunne, K. H. Andersen, M. A. Sjursen, X. Li, and M. F. Randolph. 2010. “Estimation of intact and remoulded undrained shear strengths from penetration tests in soft clay.” Géotechnique 60 (11): 843–859. https://doi.org/10.1680/geot.9.P.017.
O’Beirne, C., C. D. O'Loughlin, and C. Gaudin. 2017. “Assessing the penetration resistance acting on a dynamically installed anchor in normally consolidated and overconsolidated clay.” Can. Geotech. J. 54: 1–17. https://doi.org/10.1139/cgj-2016-0111.
Raie, M., and J. L. Tassoulas. 2009. “Installation of torpedo anchors: Numerical modeling.” J. Geotech. Geoenviron. Eng. 135 (12): 1805–1813. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000159.
Randolph, M. F., H. E. Low, and H. Zhou. 2007. “In situ testing for design of pipeline and anchoring systems.” In Proc., 6th Int. Conf. on Offshore Site Investigation and Geotechnics: Confronting New Challenges and Sharing Knowledge, 251–262. London: Society for Underwater Technology.
Schlue, B. F., T. Moerz, and S. Kreiter. 2010. “Influence of shear rate on undrained vane shear strength of organic harbor mud.” J. Geotech. Geoenviron. Eng. 136 (10): 1437–1447. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000356.
Shelton, J. T. 2007. “OMNI-maxTM anchor development and technology.” In OCEANS 2007, 1–10. New York: IEEE.
Shelton, J. T., C. Nie, and D. Shuler. 2011. “Installation penetration of gravity installed plate anchors—Laboratory study results and field history data.” In Offshore Technology Conf. Paper No. OTC 22502. Houston: Offshore Technology Conference.
Yafrate, N. J., and J. T. DeJong. 2007. “Influence of penetration rate on measured resistance with full flow penetrometers in soft clay.” In Geo-Denver 2007: New Peaks in Geotechnics: Advances in Measurement and Modeling of Soil Behavior, Geotechnical Special Publication 173, edited by D. J. DeGroot, C. Vipulanandan, J. A. Yamamuro, V. N. Kaliakin, P. V. Lade, M. Zeghal, U. El Shamy, N. Lu, and C. R. Song. Reston, VA: ASCE.
Zhou, H., and M. F. Randolph. 2009. “Resistance of full-flow penetrometers in rate-dependent and strain-softening clay.” Géotechnique 59 (2): 79–86. https://doi.org/10.1680/geot.2007.00164.
Zimmerman, E. H., M.W. Smith, and J. T. Shelton. 2009. “Efficient gravity installed anchor for deepwater mooring.” In Proc., 41st Annual Offshore Technology Conf. Paper No. OTC20117. Houston: Offshore Technology Conference.
Information & Authors
Information
Published In
Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 148 • Issue 1 • January 2022
Copyright
© 2021 American Society of Civil Engineers.
History
Received: Oct 3, 2019
Accepted: Sep 8, 2021
Published online: Nov 1, 2021
Published in print: Jan 1, 2022
Discussion open until: Apr 1, 2022
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.
Cited by
- Congcong Han, Yuming Tong, Jun Liu, The performance of the dynamically installed plate anchor in sand and silt, Ocean Engineering, 10.1016/j.oceaneng.2022.113274, 267, (113274), (2023).