Identification of effective 1D soil models for large-diameter offshore wind turbine foundations based on in-situ seismic measurements and 3D modelling

Offshore wind generated electricity is currently one of the most promising sources of energy to contribute in creating a sustainable global energy mix. The latter is essential for minimising the detrimental impact of human-induced accelerated climate change. The cost of offshore wind power has strongly decreased over the past years due to ...

Dynamic soil stiffness for foundation piles: Capturing 3D continuum effects in an effective, non-local 1D model

A method is presented to accurately capture the 3D interaction phenomena of a foundation pile embedded in soil, in a computationally efficient non-local 1D model. It is shown how to extract the global stiffness kernels from simulations with the 3D inhomogeneous continuum, and implement them in a 1D non-local Winkler-type model that can...

Effective soil-stiffness validation: Shaker excitation of an in-situ monopile foundation

In an attempt to decrease the modelling uncertainty associated with the soil-structure interaction of large-diameter monopile foundations, a hydraulic shaker was used to excite a real-sized, in-situ monopile foundation in stiff, sandy soil in a near-shore wind farm. The response in terms of natural frequency and damping of a pile-only system...

Effective stiffness method for rigid monopile foundations of offshore wind turbines and in-situ validation

It is widely accepted that the initial stiffness derived with the p-y methodology as prescribed by the American Petroleum Institute does not capture the true small-strain stiffness for rigidly behaving piles. We present an alternative method, capturing the 3D effects in the soil-pile interaction, in which the soil is characterized with in-situ...

A method for identification of an effective Winkler foundation for largediameter offshore wind turbine support structures based on in-situ measured small-strain soil response and 3D modelling

A procedure is presented for the derivation of an effective small-strain soil stiffness governing the soil– structure interaction of large-diameter monopiles. As a first step, geophysical measurements are used to estimate the depth-dependent shear modulus G of the soil stratum. The second step is to use this modulus and an estimated Poisson’s...

Assessing the small-strain soil stiffness for offshore wind turbines based on in situ seismic measurements

In this contribution, in situ seismic measurements are used to derive the small-strain shear modulus of soil as input for two soil-structure interaction (SSI) models to assess the initial soil stiffness for offshore wind turbine foundations. This stiffness has a defining influence on the first natural frequency of offshore wind turbines (OWTs),...