Techno Press
Techno Press

Wind and Structures   Volume 21, Number 6, December 2015, pages 625-639
DOI: http://dx.doi.org/10.12989/was.2015.21.6.625
 
Natural frequency of bottom-fixed offshore wind turbines considering pile-soil-interaction with material uncertainties and scouring depth
Jin-Hak Yi, Sun-Bin Kim, Gil-Lim Yoon and Lars Vabbersgaard Andersen

 
Abstract     [Full Text]
    Monopiles have been most widely used for supporting offshore wind turbines (OWTs) in shallow water areas. However, multi-member lattice-type structures such as jackets and tripods are also considered good alternatives to monopile foundations for relatively deep water areas with depth ranging from 25–50 m owing to their technical and economic feasibility. Moreover, jacket structures have been popular in the oil and gas industry for a long time. However, several unsolved technical issues still persist in the utilization of multi-member lattice-type supporting structures for OWTs; these problems include pile-soil-interaction (PSI) effects, realization of dynamically stable designs to avoid resonances, and quick and safe installation in remote areas. In this study, the effects of PSI on the dynamic properties of bottom-fixed OWTs, including monopile-, tripod- and jacket-supported OWTs, were investigated intensively. The tower and substructure were modeled using conventional beam elements with added mass, and pile foundations were modeled with beam and nonlinear spring elements. The effects of PSI on the dynamic properties of the structure were evaluated using Monte Carlo simulation considering the load amplitude, scouring depth, and the uncertainties in soil properties.
 
Key Words
    pile-soil-interaction (PSI); bottom-fixed offshore wind turbine; random sampling; natural frequency; scouring
 
Address
Jin-Hak Yi and Gil-Lim Yoon: Coastal and Environmental Engineering Division, Korea Institute of Ocean Science and Technology, Gyeonggi 426-744, Korea;
Department of Convergence Study on the Ocean Science and Technology, Ocean Science and Technology School, Korea Maritime and Ocean University, Busan, Korea
Sun-Bin Kim: Coastal and Environmental Engineering Division, Korea Institute of Ocean Science and Technology, Gyeonggi 426-744, Korea
Lars Vabbersgaard Andersen: Department of Civil Engineering, Aalborg University, Aalborg, Denmark
 

Techno-Press: Publishers of international journals and conference proceedings.       Copyright © 2018 Techno Press
P.O. Box 33, Yuseong, Daejeon 305-600 Korea, Tel: +82-42-828-7996, Fax : +82-42-828-7997, Email: technop@chol.com