題目：沙土中桶型基礎(chǔ):從數(shù)值模擬到宏單元設(shè)計(jì)工具
時(shí)間：2019年12月1日上午9:30
地點(diǎn)：巖土工程研究所綜合實(shí)驗(yàn)1號(hào)樓208室
報(bào)告人：尹振宇香港理工大學(xué)土木與環(huán)境工程系副教授
摘要:桶型基礎(chǔ)在海工結(jié)構(gòu)及海上基礎(chǔ)設(shè)施建設(shè)中被廣泛采用。本研究主要針對(duì)桶型基礎(chǔ)的設(shè)計(jì)展開數(shù)值分析，以期開發(fā)一個(gè)簡(jiǎn)化的設(shè)計(jì)工具。考慮到基礎(chǔ)大變形特點(diǎn)，本研究采用了拉格朗日-平滑粒子流體動(dòng)力學(xué)耦合方法（CL-SPH），并結(jié)合最近提出的砂土臨界狀態(tài)模型（SIMSAND）。數(shù)值分析主要集中在組合單調(diào)荷載作用下箱型基礎(chǔ)的破壞過(guò)程和破壞包絡(luò)面。然后考慮了影響破壞包絡(luò)面的形狀和大小的不同參數(shù)，例如土的密實(shí)度、剛度，摩擦角、顆粒破碎程度、地基的幾何形狀和長(zhǎng)寬比等。基于這些分析，提出了一個(gè)解析公式來(lái)描述三維破壞包絡(luò)面。最后，應(yīng)用所提出的解析公式，在亞塑性框架下開發(fā)了桶型基礎(chǔ)的宏單元設(shè)計(jì)，并進(jìn)行了驗(yàn)證。
尹振宇博士，香港理工大學(xué)土木與環(huán)境工程系副教授
尹振宇，1997年獲浙江大學(xué)建筑工程專業(yè)學(xué)士學(xué)位，2006年獲法國(guó)巖土工程專業(yè)博士學(xué)位。曾先后學(xué)習(xí)和任職于浙江嘉華建筑設(shè)計(jì)有限公司、法國(guó)南特中央理工大學(xué)(Ecole Centrale de Nantes)、同濟(jì)大學(xué)、英國(guó)斯特斯克萊德大學(xué)(University of Strathclyde)、芬蘭赫爾辛基工業(yè)大學(xué)(Helsinki University of Technology)、美國(guó)馬薩諸塞大學(xué)(University of Massachussettts, Amherst)、上海交通大學(xué)、香港理工大學(xué)，曾于2011年入選上海市特聘教授“東方學(xué)者”。兼任美國(guó)土木工程師協(xié)會(huì)（ASCE）“粒狀材料專業(yè)委員會(huì)”委員及中國(guó)多個(gè)土力學(xué)專業(yè)委員會(huì)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(xué)與巖土工程方面的教學(xué)和研究，近年來(lái)在國(guó)際核心刊物上發(fā)表SCI論文130余篇，WOS的H指數(shù)達(dá)32。
主要研究方向：（1）土體宏微觀特性及本構(gòu)關(guān)系；（2）巖土工程模型試驗(yàn)及數(shù)值分析；（3）人工智能在巖土工程中的應(yīng)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”.
