Finite Element Analyses Applied in Design of Foundations and Anchors for Offshore Structures
Publication: International Journal of Geomechanics
Volume 11, Issue 6
Abstract
Offshore structures for oil and gas exploitation are designed to accommodate severe environments with large cyclic loads. These structures are either founded directly on the seabed, or they are moored to anchors installed in the seabed soil. The permanent and cyclic loading, the foundation or anchor geometry, and the nonlinear soil behavior may be very complex, and many interrelated aspects must be considered in the geotechnical design of the foundations. Finite-element analyses (FEAs) are used increasingly to deal with these complexities and offer the potential to increase accuracy, efficiency, and reliability and reduce the uncertainty of the design process. This paper presents the major geotechnical aspects in the design of foundations for offshore structures and examples from finite-element analyses carried out at the Norwegian Geotechnical Institute (NGI) to deal with these aspects. A brief review of the procedure used at NGI to obtain soil stress-strain-strength relationships from cyclic laboratory tests is included. It is demonstrated that FEA offers several benefits over classical methods, such as limiting equilibrium calculations.
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Acknowledgments
This paper is a revised version of a paper originally presented at the 12th IACMAG conference in 2008. The writers would like to thank all colleagues who contributed to this work. We thank our colleague, Mr. Kristoffer Skau, who carried out the Abaqus analysis for the rotational stiffness of the Troll platform.
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Information & Authors
Information
Published In
International Journal of Geomechanics
Volume 11 • Issue 6 • December 2011
Pages: 417 - 430
Copyright
© 2011 American Society of Civil Engineers.
History
Received: Jul 2, 2009
Accepted: Mar 10, 2010
Published online: Mar 19, 2010
Published in print: Dec 1, 2011
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