A simplified calculation method for axial cyclic degradation of offshore wind turbine foundations in clay. Issue 2 (7th February 2020)

• Record Type: Journal Article
• Authors: Liu, Ying; Huang, Maosong; Ma, Shaokun
• Is Part Of: Marine georesources & geotechnology. Volume 38:Issue 2(2020)
• Page Start: 204
• Page End: 213
• Publication Date: 2020-02-07
• Subjects: Cyclic degradation -- axial pile capacity -- offshore wind turbine foundation -- simplified calculation method -- soft clay; Marine mineral resources -- Periodicals; 551.46
• DOI: 10.1080/1064119X.2019.1566296
• Languages: English
• ISSNs: 1064-119X

Abstract

Abstract: Pile foundation is the most popular option for the foundation of offshore wind turbines. The degradation of stiffness and bearing capacity of pile foundation induced by cyclic loading will be harmful for structure safety. In this article, a modified undrained elastic–plastic model considering the cyclic degradation of clay soil is proposed, and a simplified calculation method (SCM) based on shear displacement method is presented to calculate the axial degradated capacity of a single pile foundation for offshore wind turbines resisting cyclic loadings. The conception of plastic zone thickness Rp is introduced to obtain the function between accumulated plastic strain and displacement of soil around pile side. The axial ultimate capacity of single piles under axial cyclic loading calculated by this simplified analysis have a good consistency with the results from the finite element analysis, which verifies the accuracy and reliability of this method. As an instance, the behavior of pile foundation of an offshore wind farm under cyclic load is studied using the proposed numerical method and SCM. This simplified method may provide valuable reference for engineering design.