题目：沙土中桶型基础:从数值模拟到宏单元设计工具
时间：2019年12月1日上午9:30
地点：岩土工程研究所综合实验1号楼208室
报告人：尹振宇香港理工大学土木与环境工程系副教授
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。
尹振宇博士，香港理工大学土木与环境工程系副教授
尹振宇，1997年获浙江大学建筑工程专业学士学位，2006年获法国岩土工程专业博士学位。曾先后学习和任职于浙江嘉华建筑设计有限公司、法国南特中央理工大学(Ecole Centrale de Nantes)、同济大学、英国斯特斯克莱德大学(University of Strathclyde)、芬兰赫尔辛基工业大学(Helsinki University of Technology)、美国马萨诸塞大学(University of Massachussettts, Amherst)、上海交通大学、香港理工大学，曾于2011年入选上海市特聘教授“东方学者”。兼任美国土木工程师协会（ASCE）“粒状材料专业委员会”委员及中国多个土力学专业委员会委员，日本土工（S & F）、加拿大土工（Can.Geot. J.）等期刊编委，主要从事土力学与岩土工程方面的教学和研究，近年来在国际核心刊物上发表SCI论文130余篇，WOS的H指数达32。
主要研究方向：（1）土体宏微观特性及本构关系；（2）岩土工程模型试验及数值分析；（3）人工智能在岩土工程中的应用。
Title: Offshore caisson foundation in sand: from numerical modelling to macroelement design tool
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, 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 experimentalresults.
Dr Zhen-Yu YIN,Associate Professorof Geotechnics at The Hong Kong Polytechnic University.
Dr. Yin was graduated from Zhejiang University in 1997 for BSc, and then worked as engineer at Zhejiang Jiahua Architecture Design Institute for 5 years. He obtained MSc and PhD in Geotechnical Engineering at Ecole Centrale de Nantes in France in 2003 and 2006.
After PhD, he worked as research and teaching fellow mainly at Helsinki University of Technology (Finland), University of Strathclyde (UK), University of Massachusetts (Umass-Amherst, USA), Shanghai Jiao Tong University, Tongji University and Ecole Centrale de Nantes in France, and HK PolyU.
Dr. Yin’s research interests include: (1) constitutive modeling of soils from micro to macro; (2) finite element analysis for geotechnical engineering; (3) application of artificial intelligence in geotechnics. Since 2008, he has published over 130 SCI articles in peer reviewed international journals with H-index of WOS of 32.
Dr. Yin leads rresearch programmes funded by NSFC, ANR, EU-PF7, RGC etc.He served as member of granular materials committee of American Society of Civil Engineers since 2012. He is currently Editorial Board Member of “Canadian Geotechnical Journal”, “Soils and Foundations”.
