Investigation of the effects of nonlinear soil-structure interaction for a jacket-founded offshore wind turbine

Offshore wind energy is expanding rapidly as governments aim for net-zero emissions, with monopiles and jackets being the primary foundation methods for offshore wind turbines (OWTs). Supply chains, heavier turbines and deeper waters influence the efficiency of jacket foundations. This research considers a jacket-founded OWT. The development of...

First steps into the calibration chamber pile tests with glauconitic sands: On the behaviour of the sand fraction from glauconitic sand of the Kattendijk formation in Antwerp, Belgium

The Global Wind Energy Council (GWEC) forecasts an accelerated increase in wind installations as a result of the aggressive climate change and green energy objectives set by the majority of countries. As a consequence, new regions worldwide that were previously thought to be unsuitable for the construction of offshore wind farms due to the soil...

Feasibility of using a Helical Pile Foundation System to support a 15MW FOWT using a Tension Leg Mooring System: A study into the performance of a helical pile anchoring system for a TLP

This thesis explores the feasibility of using a helical pile foundation with a tension leg mooring system to support a 15MW floating offshore wind turbine and assesses its financial viability compared to alternative anchor concepts.<br/><br/>The study commenced with an extensive literature review, drawing from a diverse range of sources,...

Soil – Anchor Interaction of a Floating Offshore Wind Turbine under Cyclic Load

The rapid growth of Floating Offshore Wind (FOW) has spurred intensive research across various aspects of the floating system. A standard practice in mooring system design within the industry is that anchors remain fixed on the seabed. In contrast, plate-type anchors exhibit mobility under loading, a crucial factor considering the thousands of...

Lateral Response of Monopiles in Sand under Monotonic and Cyclic Loads: A 3D Finite Element Investigation

Large-diameter monopiles serve as foundations for offshore wind turbines (OWT), and the diameters are now up to 10 meters. These monopiles exhibit lower embedded length-to-diameter (L/D) ratios compared to the conventional monopile that is widely employed in offshore oil and gas platforms. They undergo rotation when subjected to lateral loading...

Soil-Monopile Interaction: from Elastic to Elastoplastic soil reaction modelling under Quasi-Static Monotonic Loading

Offshore wind energy's rapid expansion underscores the need for accurate and efficient methods to analyze the behavior of monopile foundations supporting wind turbines. While three-dimensional (3D) analyses provide comprehensive insights, their computational demands are significant. As an alternative, one-dimensional (1D) models with spring...

Is under-base filling necessary?: Assessing behaviour of partially installed suction caisson

In the past decade, suction caissons have emerged as a preferred offshore foundation solution for wind turbines due to their silent installation process and potential for recyclability. However, there has been growing speculation regarding the necessity of under base filling, which involves filling the gap between the top plate of the suction...

Design of a constant diameter retractable Jet-ring with inside-out jetting combined with a Vibro-hammer

Reducing noise pollution during offshore monopile installation is crucial for marine life. Current installation methods create too much noise or do not have the certainty of reaching the required depths. By using a Vibrohammer combined with a Jet-ring this problem could be solved. A Jet-ring is a tool to reduce the sand induced inside shaft...

Optimization of the installation sequence of an Offshore Wind Farm Monopile Installation Template: by improving the foundation design

Heerema Marine Contractors is assigned to execute the installation of 64 monopiles for the He Dreiht Offshore Wind Farm provided by Energie Baden-Württemberg (EnBW). The installation of the monopiles is done by means of a template structure. This template is specifically designed for this project and is installed on the seabed temporarily. The...

Uplift behavior of offshore shallow foundations during retrieval: An experimental study on the pressure differences that occur during uplift of mud-mats of pre-piling templates

Offshore structures are often founded on mud-mat foundations which prevent the structure from settling excessively. Pressure differences are generated under mud-mats during removal from the seabed. These differences lead to a force that resists the uplift. A literature study on breakout resulted in a hypothesized distinction of four mechanisms...

Dynamic modelling of offshore monopile decommissioning: A study into the first moments of complete removal of monopiles

The offshore wind sector in Europe has grown significantly over the past 20 years. Following this surge in number of installations, the first generation of turbines is reaching its end-of-life (EOL) phase and thought needs to be put into end-of-life strategies. As the market for lifetime extension is still in its infancy and...

Seismic response of monopile foundations for offshore wind turbines: from 3D to 1D modelling of soil-foundation interaction

New offshore wind farms consisting of monopile-founded Offshore Wind Turbines (OWTs) are to be built in earthquake-prone areas. To design the monopile foundation and to accurately define the dynamic response of an OWT, the soil-monopile-superstructure interaction should be modelled properly. Due to the fact that the Three-Dimensional (3D) Finite...

3D FE seismic analysis of a monopile-supported offshore wind turbine in a non-liqueable soil deposit

This work presents a numerical study on the dynamic response of monopile-supported offshore wind turbines (OWTs) under seismic loading conditions. For this purpose the realistic design ofa 8 MW OWT is considered as ideally located in a layered, non-liqueable site off the coast of Japan. This choice allowed to employ available site...