Spudcan foundation-soil coupled finite element models considering cyclic weakening effect of soil is established for offshore wind turbine installation platform. By comparing with centrifuge model tests, the reliability of numerical methods in simulating spudcan foundations under cyclic loading is demonstrated, and a series of engineering-scale numerical models are established. The research results indicate that when mono-spudcan foundation is subjected to horizontal cyclic loading, soil weakening occurs in shallow soil around the pile and spherical band of the spudcan, resulting in cumulative vertical settlement. When horizontal lateral loads are applied on the four-leg platforms, the main failure mode is excessive vertical settlement of compressed pile legs. Under bi-directional cyclic loading, accumulated settlement of compressed piles is greater than that under uni-directional loading. When the cyclic amplitude exceeds 55% of the static bearing capacity, the platform inclination continuously increases with increasing cycle numbers, affecting the safety of offshore wind turbine installation platform. Eventually, the vertical settlement of the compressed piles becomes too large, and the platform fails.
Key words
wind power installation platform /
cyclic loads /
bearing capacity /
accumulative settlement /
spudcan foundation
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