主讲人简介：
尹振宇，香港理工大学土木与环境工程系副教授。兼任美国土木工程师协会“粒状材料专业委员会”委员，欧洲土木与环境期刊副主编、多本国际期刊编委（加拿大土工、日本土工、IJOM-ASCE、Geotechnique Letters、Acta Geotechnica、Transportation Geotechnics等），主要从事岩土工程教学和科研工作，近年来在国际核心刊物上发表SCI论文190余篇，WoS的H指数为38。主要研究方向有：土体宏微观特性及本构关系、岩土工程大变形数值分析、人工智能在岩土工程中的应用。
摘要:
桶型基础在海工结构及海上基础设施建设中被广泛采用。本研究主要针对桶型基础的设计展开数值分析，以期开发一个简化的设计工具。考虑到基础大变形特点，本研究采用了拉格朗日-平滑粒子流体动力学耦合方法（CL-SPH），并结合最近提出的砂土临界状态模型（SIMSAND）。数值分析主要集中在组合单调荷载作用下箱型基础的破坏过程和破坏包络面。然后考虑了影响破坏包络面的形状和大小的不同参数，例如土的密实度、刚度，摩擦角、颗粒破碎程度、地基的几何形状和长宽比等。基于这些分析，提出了一个解析公式来描述三维破坏包络面。最后，应用所提出的解析公式，在亚塑性框架下开发了桶型基础的宏单元设计，并进行了验证。
Abstract:
This work deals with the response of caisson foundations in sand for offshore wind turbines submitted to combined monotonic and cyclic loadings. First, the failure process and failure envelope (or bearing capacity diagram) of a caisson foundation in sand under combined monotonic loadings is numerically investigated. A Combined Lagrangian-Smoothed Particle Hydrodynamics (CLSPH) method is adopted to consider large deformation. A recently developed critical state model for sand (SIMSAND) is then introduced and combined with the CLSPH method. Different parameters affecting the shape and size of the failure envelope are considered, such as soil density and stiffness, friction strength, grain breakage, geometry and aspect ratio of the foundation. An analytical formula is introduced to describe the 3D failure surface reproducing the numerical results. Based on the proposed analytical formula, a macro-element for the caisson foundation in sand submitted to monotonic and cyclic loadings is finally developed within the framework of hypoplasticity. Validation is provided through comparison with experimental results.