Abstract
Drag anchor is one of the most commonly used anchorage foundation types. The prediction of embedded trajectory in the process of drag anchor installation is of great importance to the safety design of mooring system. In this paper, the ultimate anchor holding capacity in the seabed soil is calculated through the established finite element model, and then the embedded motion trajectory is predicted applying the incremental calculation method. Firstly, the drag anchor initial embedded depth and inclination angle are assumed, which are regarded as the start embedded point. Secondly, in each incremental step, the incremental displacement of drag anchor is added along the parallel direction of anchor plate, so the displacement increment of drag anchor in the horizontal and vertical directions can be calculated. Thirdly, the finite element model of anchor is established considering the seabed soil and anchor interaction, and the ultimate drag anchor holding capacity at new position can be obtained. Fourthly, the angle between inverse catenary mooring line and horizontal plane at the attachment point at this increment step can be calculated through the inverse catenary equation. Finally, the incremental step is ended until the angle of drag anchor and seabed soil is zero as the ultimate embedded state condition, thus, the whole embedded trajectory of drag anchor is obtained. Meanwhile, the influences of initial parameter changes on the embedded trajectory are considered. Based on the proposed method, the prediction of drag anchor trajectory and the holding capacity of mooring position system can be provided.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Aubeny, C. and Chi, C.M., 2010. Mechanics of drag embedment anchors in a soft seabed, Journal of Geotechnical and Geoenvironmental Engineering, 136(1), 57–68.
Aubeny, C. and Chi, C.M., 2014. Analytical model for vertically loaded anchor performance, Journal of Geotechnical and Geoenvironmental Engineering, 140(1), 14–24.
Aubeny, C.P., Murff J.D. and Kim, B.M., 2008. Prediction of anchor trajectory during drag embedment in soft clay, International Journal of Offshore and Polar Engineering, 18(4), 314–319.
Balasuriya, S., 2016. A numerical scheme for computing stable and unstable manifolds in nonautonomous flows, International Journal of Bifurcation and Chaos, 26(14), 1630041.
Das, B.M., 1978. Model tests for uplift capacity of foundations in clay, Soils and Foundations, 18(2), 17–24.
Degenkamp, G. and Dutta, A., 1989. Soil resistances to embedded anchor chain in soft clay, Journal of Geotechnical Engineering, 115(10), 1420–1438.
Gaudin, C., Simkin, M., White, D.J. and O'Loughlin, C.D., 2010. Experimental investigation into the influence of a keying flap on the keying behaviour of plate anchors, Proceedings of the 20th International Offshore and Polar Engineering Conference, International Society of Offshore and Polar Engineers, Beijing, China.
Li, P.D., Liu, H.X. and Zhao, Y.B., 2016. Large deformation finite element analysis on the kinematic behavior of drag anchors in the seabed, The Ocean Engineering, 34(2), 56–63. (in Chinese)
Liu, H.X., Zhang, W. and Zhang, X.M., 2010. Experimental investigation on the penetration mechanism and kinematic behavior of drag anchors, Applied Ocean Research, 32(4), 434–442.
Neubecker, S.R. and Randolph, M.F., 1995. Profile and frictional capacity of embedded anchor chains, Journal of Geotechnical Engineering, 121(11), 797–803.
Neubecker, S.R. and Randolph, M.F., 1996. The performance of drag anchor and chain systems in cohesive soil, Marine Georesources and Geotechnology, 14(2), 77–96.
Omega Marine Services International, 1990. Joint industry project: Gulf of mexico large scale anchor tests—test report, Houston: Omega Marine Services International.
O'Neill, M., Bransby, M.F. and Randolph, M.F., 2003. Drag anchor fluke-soil interaction in clays, Canadian Geotechnical Journal, 40(1), 78–94.
Qiao, D.S., Bao, M., Yan, J., Zhou, D.C. and Li, Y.G., 2018. A method to predict embedded trajectory based on the finite element analyses of bearing capacity of drag anchor, Proceedings of the ASME 37th International Conference on Ocean, Offshore and Arctic Engineering, ASME, Madrid, Spain.
Ruinen, R. and Degenkamp, G., 2002. Prediction of the holding capacity and trajectory of drag embedment anchors, Proceedings of the Offshore Technology Conference, OTC, Houston, Texas, pp. 52–54.
Ruinen, R.M., 2004. Penetration analysis of drag embedment anchors in soft clays, Proceedings of the 14th International Offshore and Polar Engineering Conference, International Society of Offshore and Polar Engineers, Toulon, France.
Sukumaran, B., McCarron, W.O., Jeanjean, P. and Abouseeda, H., 1999. Efficient finite element techniques for limit analysis of suction caissons under lateral loads, Computers and Geotechnics, 24(2), 89–107.
Tian, Y., Randolph, M.F. and Cassidy, M.J., 2015. Analytical solution for ultimate embedment depth and potential holding capacity of plate anchors, Geotechnique, 65(6), 517–530.
Wu, X., Chow, Y.K. and Leung, C.F., 2016. Prediction of drag anchor trajectory with both shallow and deep anchor behavior, Proceedings of the Offshore Technology Conference Asia, OTC, Kuala Lumpur, Malaysia.
Zhao, Y.B. and Liu, H.X., 2016. Numerical implementation of the installation/mooring line and application to analyzing comprehensive anchor behaviors, Applied Ocean Research, 54, 101–114.
Author information
Authors and Affiliations
Corresponding authors
Additional information
Foundation item: This work was financially supported by the National Natural Science Foundation of China (Grant Nos. 51890915, 51490672, and 51761135011) and the Fundamental Research Funds for the Central Universities.
Rights and permissions
About this article
Cite this article
Qiao, Ds., Guan, B., Liang, Hz. et al. An Improved Method of Predicting Drag Anchor Trajectory Based on the Finite Element Analyses of Holding Capacity. China Ocean Eng 34, 1–9 (2020). https://doi.org/10.1007/s13344-020-0001-0
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13344-020-0001-0