We provided modelling to support decision making around potential remedial activities for scour of a turbine foundation.
Confidential
Our customer had an issue with scour around a particular turbine foundation at an operational offshore wind farm. Frazer-Nash was asked to provide modelling to support decision making around potential remedial activities and operational parameters.
An assessment was performed to understand the effect of scour on the utilisation of the wind farm pile. This assessment used a finite element approach to model the response of the pile and the nonlinear effect of the soil support.
Comparisons were initially performed between the results presented in the original design report and those from a model representing the ‘as built’ condition. This demonstrated comparable utilisations against buckling, based on an assessment to code. A version of this model was then created using updated soil support properties, which represented the scour as observed in the previous year. This reduced the length of pile embedded considerably when compared to the ‘as built’ model.
We showed that both pile stress and deflection had increased significantly, due to changes in embedment depth and the different soil resistance curves used in the respective assessments. Though the relative importance of each was not assessed initially, our work was used to support decision making around how to extend the life of the asset.
