在海上风电桩基工程计算时,为方便土体本构关系的使用,减少土工参数的选取,对修正剑桥模型进行了改进。首先根据海洋工程中桩周土体通常为K0固结饱和土的特点,在修正剑桥模型的基础上,引入相变参数,推导出适用于剪胀性土体的屈服面函数;然后参考统一硬化模型的研究理念,引入耗散功作为硬化参量,结合传统弹塑性理论,对Collins的热力学土体模型进行改进,提出了一种同时适用于砂土与黏土的新的统一修正剑桥模型;最后采用2个案例进行验证。研究结果表明:提出的本构模型具有计算精度高、选用计算参数少且物理意义明确的特点,可为海洋工程基础的相关计算提供参考。
Abstract
The modified Cam-Clay model is improved to facilitate the use of soil constitutive model and reduce the selection of geotechnical parameters in the calculation of offshore wind power pile foundation. Firstly, according to the characteristics of K0 consolidated saturated soil in ocean engineering, the yield surface function suitable for dilatant soil is derived by introducing phase change parameters based on the modified Cam-Clay model. Furthermore, referring to the research concept of the unified hardening model, the dissipative work is introduced as hardening parameter to improve the thermodynamic soil model of Collins in association with the traditional elastic-plastic theory. A new unified modified Cam-Clay model suitable for both sand and clay is proposed. Finally, case analysis is carried out to verify the model. Results demonstrate that the constitutive model proposed in this paper needs few calculation parameters, and is of high accuracy and clear physical meaning.
关键词
海洋土体 /
K0固结 /
耗散功 /
硬化参量 /
统一修正剑桥模型
Key words
marine soil /
K0 consolidation /
dissipated work /
hardening parameters /
unified modified Cam-Clay model
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基金
湖南省自然科学基金项目(2019JJ50030);湖南省教育厅科学研究项目(18C0850)
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