Influence of soil nonlinearity on the seismic behaviour of monopile foundations
File(s)
Published version
Author(s)
Ortiz Wall, Fabian
Taborda, David
Kontoe, Stavroula
Moller, Julia
Type
Conference Paper
Abstract
The growth of the offshore industry has led to the installation of offshore wind turbines (OWTs) in seismic
regions, adding complexity to their design. Seismic loads can impose significant deformation on the soil, resulting in highly nonlinear behaviour. Designing structural systems for these conditions requires complex methodologies for the adequate prediction of their behaviour, such as finite element modelling (FEM) coupled with constitutive models that accurately reproduce the cyclic soil response – an often-challenging task. This study employs dynamic FEM with a cyclic nonlinear elastic model with enhanced hysteresis control to analyse the impact of nonlinear soil behaviour on soil-structure interaction (SSI) under seismic loading. Additionally, equivalent linear (EQL) site response analyses are used to retrieve shear wave velocity and damping profiles of the soil under seismic conditions and inform a new set of numerical analyses. Significant differences were observed between the predictions of the two approaches, influenced by the soil’s dynamic properties and seismic intensity. For the pile geometry, soil profile and load cases considered in this study, EQL models appears suitable as a conservative first approximation for design purposes.
regions, adding complexity to their design. Seismic loads can impose significant deformation on the soil, resulting in highly nonlinear behaviour. Designing structural systems for these conditions requires complex methodologies for the adequate prediction of their behaviour, such as finite element modelling (FEM) coupled with constitutive models that accurately reproduce the cyclic soil response – an often-challenging task. This study employs dynamic FEM with a cyclic nonlinear elastic model with enhanced hysteresis control to analyse the impact of nonlinear soil behaviour on soil-structure interaction (SSI) under seismic loading. Additionally, equivalent linear (EQL) site response analyses are used to retrieve shear wave velocity and damping profiles of the soil under seismic conditions and inform a new set of numerical analyses. Significant differences were observed between the predictions of the two approaches, influenced by the soil’s dynamic properties and seismic intensity. For the pile geometry, soil profile and load cases considered in this study, EQL models appears suitable as a conservative first approximation for design purposes.
Date Issued
2025-06-09
Date Acceptance
2025-06-08
Citation
Proceedings of ISFOG 2025, 2025, pp.1-7
ISBN
978-2-85782-758-0
Publisher
International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE)
Start Page
1
End Page
7
Journal / Book Title
Proceedings of ISFOG 2025
Copyright Statement
© 2025 the Authors.
Source
5th International Symposium on Frontiers in Offshore Geotechnics (ISFOG2025)
Publication Status
Published
Start Date
2025-06-09
Finish Date
2025-06-13
Coverage Spatial
Nantes, France