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Analysis of Offshore Rock Socketed Monopile Foundations Considering Stiffness Degradation

Conference paper
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Part of the Sustainable Civil Infrastructures book series (SUCI)

Abstract

There are a number of offshore wind farms where the monopile is socketed into rock layers. Since it is socketed into rock, it may behave different from monopile embedded in soil. A numerical modelling of rock socketed monopile is done using finite element (FE) software Abaqus. A stiffness degradation method (SDM) is applied to FE model in order to predict the behaviour under cyclic loading conditions. Parametric studies are carried out by varying rock socketed depth (d), length of monopile below seabed (L), intensity of horizontal loading (H) and subsoil conditions to evaluate the long-term permanent deformation of offshore rock socketed monopile foundations. Suitable permanent deformation factors are proposed for offshore rock socketed monopiles for the first time in the literature. It is observed from the results that the deformation behaviour of the monopile changes from stiff to flexible with increase in rock socketing and in turn the pile head deflection going down. From the bending moment diagram, flexible and stiff behaviour of monopile can be identified and is an indicator of curvature of the deflection line of pile.

Keywords

Cyclic loading Rock socketed monopiles Stiffness degradation method Numerical modelling Lateral deformation 

Notes

Acknowledgements

This work has been carried out with scholarship funded by DAAD for Ms. Navy Basheer for a period of six months. This work is a result of collaboration between Institute for Geotechnical Engineering, LUH, Germany and Department of Civil Engineering, IIT Delhi, India.

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Copyright information

© Springer International Publishing AG, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Civil EngineeringIndian Institute of Technology (IIT) DelhiHauz Khas, New DelhiIndia
  2. 2.Institute for Geotechnical Engineering (IGtH), Leibniz University of HannoverHannoverGermany

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