题目：Soil Mechanics at the Grain Scale with Applications to Bio-Cementation
颗粒尺度土力学：生物胶结土中的应用
时间：2018年4月23日（周一）上午10:00 - 12:00
地点：七号楼二楼大会议室
报告人：美国俄勒冈州立大学T. Matthew Evans副教授
欢迎广大师生参加
土木与交通学院
2018年4月17日
报告人简介：
Matt is an Associate Professor in the School of Civil and Construction Engineering at Oregon State University. Prior to coming to OSU he spent six years as an Assistant Professor at North Carolina State University. His research interests include granular mechanics, multiphysics processes, quantitative stereology, image processing and morphology, soil mechanics, and geotechnical engineering. He serves on the editorial board of the ASCE Journal of Geotechnical and Geoenvironmental Engineering and Soils and Foundations. He is the chair of the Soil Properties and Modeling Committee of the ASCE Geo-Institute. He earned his M.S. and Ph.D. in civil engineering from the Georgia Institute of Technology, a B.S. in civil engineering from the University of New Mexico, and a B.A. in physics from the University of Virginia.
Dr. Evans于2005年获佐治亚理工学院土木工程博士学位，随后任教于北卡州立大学，现任俄勒冈州立大学岩土工程系副教授，美国土木工程师学会会员，美国大学岩土工程教育与研究理事会会员，曾多次担任ASCE GeoCongress 大会的副主席。 Evans 教授主持和参与美国国家自然科学基金项目十余项，在国际著名期刊上发表学术论文50余篇，岩土工程著名期刊JGGE副编辑、Soil and Foundation编委等。
报告摘要：
Particulate materials do not: have inherent strength and stiffness (like a solid); flow freely (like a liquid); or compress easily (like a gas). The unique combination of properties possessed by granular materials includes that they are: inherently multiphase, porous, and pervious; nonlinear and inelastic; their volume changes during shear; and strength and stiffness depend on confinement, strain rate, and stress path. Given these observations, particulate materials are effectively a separate phase of matter – neither solid, liquid, nor gas. Granular materials are not always amenable to continuum descriptions of behavior, so in some cases a discrete approach is adopted for modeling.
Bio-cementation, a novel and promising approach for the stabilization of liquefiable sand deposits in-situ, will be used to motivate a broader discussion of grain-scale soil mechanics. The talk will begin by providing a survey of soils as assemblies of discrete particles and provide an introduction to the discrete element method (DEM) for the simulation of the mechanical behavior of granular materials. In DEM modeling, every grain in an assembly is modeled individually and simulation involves solution of Newton’s equations of motion for every particle at every time step. After an introduction of modeling basics and a brief discussion of particle-continuum duality, the mechanical behavior of bio-cemented sands will be explored.
