黏土中桶式基础的宏单元模拟

本研究旨在对黏土中的桶式基础进行从完整的有限元分析到简化的宏单元的建模。首先通过有限元方法分析了在不同单调组合荷载作用下的黏土中吸力桶基础。为保证模拟结果的可靠性，采用了硬化土模型（HS）对正常固结黏土地基进行模拟。通过对比离心试验验证了使用HS模型的有限元分析的有效性，并通过径向位移试验进一步延伸到V-H-M（竖向力-水平力-弯矩）空间的破坏模式研究，并在此基础上，提出了的V-H-M空间三维破坏包络面公式。接着，应用此三维破坏包络面公式，采用亚塑性框架提出了黏土中桶式基础的宏单元设计模型。通过与试验结果的比较，验证了宏单元模型在模拟单调和循环荷载条件下桶式基础的强度与变形响应的有效性。所提的宏单元模型对于海洋岩土工程设计实践将很有帮助。

Macroelement modelling of caisson foundation in clay

The purpose of this study is to model the caisson in clay from a complete finite element analysis to a simplified microelement modeling. First, the finite element method is used to analyze the caisson foundation in clay under different monotonic combined loadings. To ensure the reliability of the simulation results, the hardened soil model (HS) is adopted to simulate the normally consolidated clay. The effectiveness of the finite element analysis using the HS model is verified through comparing with centrifugal tests, and the swipe tests with radial displacement control is further extended to the study of failure modes in V-H-M (vertical force-horizontal force-bending moment) space. A three-dimensional failure envelope formula for the caisson foundation in clay in V-H-M space is proposed. Then, using this three-dimensional failure envelope formula, a macroelement design model for the caisson foundation in clay is proposed using a hypoplastic framework. By comparing with the experimental results, the validity of the strength and deformation response of the caisson foundation under simulated monotonic and cyclic loading conditions are verified. The proposed macroelement based model is practically useful in marine geotechnical design.