Session: 10-03-01 Anchoring and Mooring Systems

Paper Number: 124377

124377 - Examination of an Analytical Approach for Load-Displacement Behavior of Drag Embedment Anchors and Their Geometrical Optimization 

Floating offshore renewables are anchored to the seabed to maintain their position. One form of anchorage is the drag embedment anchor (DEA). Industry standards rely on analytical solutions to evaluate the required holding power and displacement behavior of DEAs. Although these solutions are essential for infrastructure assessment, their complexity can make them challenging to interpret.

This research offers a thorough parametric and graphical analysis of a prominent analytical solution applied by classification societies like ABS and DNV to predict the load-displacement behavior of DEAs in clay environments. The objectives are to give a clear understanding of the calculations inherent to this solution and identify optimal DEA geometry. The study determines a simplified DEA's optimal shaft and fluke lengths, using criteria such as cost-effectiveness (minimal volume) and safety (maximum bearing capacity and maximum penetration depth). 

This assessment results in a Pareto front, encompassing various optimal solutions regarding the predefined objectives. A comparative examination of five selected optimal DEA configurations reveals that, while there are minor geometrical differences (under 5 % variations in the shank and fluke lengths), these configurations have significant effects on embedment depth, bearing capacity, and volume, with variations of up to 20 %. Numerical LDFE analyses applying FEM CEL verify the obtained results.

Conclusively, this study demonstrates the utility of established analytical solutions in predicting the load-displacement behavior of DEAs. Their applicability in determining optimal anchor geometries has implications for both economic efficiency and safety. Such findings hold the potential to guide future decisions in designing sustainable and reliable offshore infrastructures.

Presenting Author: Duy Anh Dao Hamburg University of Technology

Presenting Author Biography: Duy Dao is a PhD student specializing in offshore geotechnics research at the Institute of Geotechnical Engineering, Hamburg University of Technology (TUHH). He holds a master's degree in Civil Engineering, from TUHH, Germany, with a specialization in Geotechnics.
His research journey began with an industry project focused on ship anchor penetration analysis, laying the foundation for his expertise in structure-soil interaction. Over time, his focus shifted towards anchoring systems for floating offshore wind turbines. His work is characterized by its interdisciplinary nature, involving collaboration with geotechnical engineers, hydraulic engineers, and naval architects.
Duy Dao is committed to advancing offshore geotechnics research and its practical applications.

Authors:

Duy Anh Dao Hamburg University of Technology
Jürgen Grabe Hamburg University of Technology
Alexander Chmelnizkij Hamburg University of Technology