针对海上风电安装平台桩靴基础,建立考虑土体循环弱化的桩靴-土体耦合有限元模型,通过与离心机模型试验对比,证明其在模拟桩靴基础循环特性方面的可靠性,并针对工程尺度的四腿安装平台进行一系列的循环加载分析。研究结果表明,单个桩靴基础在水平循环加载下,表层桩周土体和桩靴周围球形带处发生土体弱化,产生累积竖向沉降;四腿平台在水平荷载作用下主要失效模式为受压桩腿竖向沉降过大,双向水平循环加载下受压桩累积沉降大于单向加载情况,当循环幅值大于55%静承载力时,随着循环次数增加,平台倾斜率不断增加,影响风电安装平台在位作业安全性,最终受压桩竖向沉降过大,平台失效。
Abstract
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.
关键词
风电安装平台 /
循环荷载 /
承载力 /
累积沉降 /
桩靴基础
Key words
wind power installation platform /
cyclic loads /
bearing capacity /
accumulative settlement /
spudcan foundation
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参考文献
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基金
国家自然科学基金（62273060）; 湖北省教育厅科学研究计划（D20211302）
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