題目：沙土中桶型基礎:從數值模擬到宏單元設計工具
時間：2019年12月1日上午9:30
地點：巖土工程研究所綜合實驗1號樓208室
報告人：尹振宇香港理工大學土木與環境工程系副教授
摘要:桶型基礎在海工結構及海上基礎設施建設中被廣泛采用。本研究主要針對桶型基礎的設計展開數值分析，以期開發一個簡化的設計工具。考慮到基礎大變形特點，本研究采用了拉格朗日-平滑粒子流體動力學耦合方法（CL-SPH），并結合最近提出的砂土臨界狀態模型（SIMSAND）。數值分析主要集中在組合單調荷載作用下箱型基礎的破壞過程和破壞包絡面。然后考慮了影響破壞包絡面的形狀和大小的不同參數，例如土的密實度、剛度，摩擦角、顆粒破碎程度、地基的幾何形狀和長寬比等。基于這些分析，提出了一個解析公式來描述三維破壞包絡面。最后，應用所提出的解析公式，在亞塑性框架下開發了桶型基礎的宏單元設計，并進行了驗證。
尹振宇博士，香港理工大學土木與環境工程系副教授
尹振宇，1997年獲浙江大學建筑工程專業學士學位，2006年獲法國巖土工程專業博士學位。曾先后學習和任職于浙江嘉華建筑設計有限公司、法國南特中央理工大學(Ecole Centrale de Nantes)、同濟大學、英國斯特斯克萊德大學(University of Strathclyde)、芬蘭赫爾辛基工業大學(Helsinki University of Technology)、美國馬薩諸塞大學(University of Massachussettts, Amherst)、上海交通大學、香港理工大學，曾于2011年入選上海市特聘教授“東方學者”。兼任美國土木工程師協會（ASCE）“粒狀材料專業委員會”委員及中國多個土力學專業委員會委員，日本土工（S & F）、加拿大土工（Can.Geot. J.）等期刊編委，主要從事土力學與巖土工程方面的教學和研究，近年來在國際核心刊物上發表SCI論文130余篇，WOS的H指數達32。
主要研究方向：（1）土體宏微觀特性及本構關系；（2）巖土工程模型試驗及數值分析；（3）人工智能在巖土工程中的應用。
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”.
