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Access Type
Open Access
Document Type
thesis
Degree Program
Civil Engineering
Degree Type
Master of Science in Civil Engineering (M.S.C.E.)
Year Degree Awarded
2012
Month Degree Awarded
May
Keywords
reliability, monopile foundation, offshore wind turbine
Abstract
A literature review of current design and analysis methods for offshore wind turbine (OWT) foundations is presented, focusing primarily on the monopile foundation. Laterally loaded monopile foundations are typically designed using the American Petroleum Institute (API) p-y method for offshore oil platforms, which presents several issues when extended to OWTs, mostly with respect to the large pile diameters required and the effect of cyclic loading from wind and waves. Although remedies have been proposed, none have been incorporated into current design standards. Foundations must be uniquely designed for each wind farm due to extreme dependence on site characteristics. The uncertainty in soil conditions as well as wind and wave loading is currently treated with a deterministic design procedure, though standards leave the door open for engineers to use a probability-based approach. This thesis uses probabilistic methods to examine the reliability of OWT pile foundations. A static two-dimensional analysis in MATLAB includes the nonlinearity of p-y soil spring stiffness, variation in soil properties, sensitivity to pile design parameters and loading conditions. Results are concluded with a natural frequency analysis.
DOI
https://doi.org/10.7275/2761598
First Advisor
Sanjay R. Arwade
Second Advisor
Don J. DeGroot