Static and Dynamic Behavior of Unsaturated Soils - Theory and Validation

9501718 Muraleetharan目的是开发一个完全耦合的分析程序来研究非饱和土的静态和动态行为，并使用土工离心模型试验结果来验证分析程序。 分析过程涉及到由孔隙流体、孔隙气体和土壤骨架组成的三相系统的动力学行为方程的有限元实现。通过将流体饱和多孔介质的动力学行为的毕奥公式扩展到三相系统来推导控制方程，并使用混合物理论进行独立验证。在开发这些控制方程，特别注意的是集中在定义适当的本构方程。 该分析程序将提高对填埋场粘土覆盖层、底部衬垫和压实土壤填料等结构的静态和地震荷载性能和设计的理解。开发的分析程序还将有助于防止每年因土壤收缩和膨胀而对房屋、建筑物、道路和管道造成的巨大经济损失。此外，分析程序以及离心试验将提供一个更好地了解通过非饱和土壤，在研究污染物通过土壤迁移的一个重要问题的水的流动。 教育计划 该教育计划是一种全面的方法，使本科生和研究生熟悉地质环境工程的新兴跨学科领域以及岩土工程和地质环境工程的当前研究和行业实践。 目的是在本科课程中引入更多跨学科的真实的世界设计问题，例如在基本原理的教学中引入多媒体模块，让学生按照自己的节奏探索某个主题。另一个目标是为本科生购买一台小型教学离心机，并向他们介绍岩土工程和地质环境工程中的这一重要研究工具。 鼓励研究生通过在他们的研究中结合实验和分析方面来获得广泛的知识基础，以及与他们的论文或论文主题之外的其他教师一起从事项目。 开发一门研究生水平的课程，称为“环境岩土工程”，这也可以作为一个专业选修课的本科生，强调岩土工程问题在解决环境问题的重要性。 ***

9501718 Muraleetharan The objective is to develop a fully-coupled analysis procedure to study the static and dynamic behavior of unsaturated soils, and to validate the analysis procedure using geotechnical centrifuge model test results. The analysis procedure involves the finite element implementation of the equations governing the dynamic behavior of a three-phase system consisting of pore fluid, pore gas and soil skeleton. The governing equations are derived by extending Biot's formulation for the dynamic behavior of a fluid-saturated porous media to a three-phase system, with an independent verification using mixture theory. In developing these governing equations, special attention is focused on defining the appropriate set of constitutive equations. This analysis procedure will improve the understanding of the behavior and design for static and earthquake loading of structures such as landfill clay covers and bottom liners and compacted soil embankments. The developed analysis procedure will also help to prevent the huge financial losses caused each year by the damage to houses, buildings, roads and pipelines resulting from the shrinking and swelling of soils. Furthermore, the analysis procedure as well as the centrifuge tests will provide a better understanding of the flow of water through unsaturated soils, an important problem in studying the migration of pollutants through soils. EDUCATION PLAN The education plan is a comprehensive approach to familiarizing undergraduate and graduate students with the emerging cross-disciplinary field of geo-environmental engineering and current research and industry practices in geotechnical and geo-environmental engineering. An objective is to introduce more multi-disciplinary real world design problems into the undergraduate courses, such as introducing multi-media modules in the teaching of basic principles so as to allow the students to explore a certain topic at their own pace. Another objective is to acquire a small teaching centrifuge for undergraduate students and to introduce them to this important research tool in geotechnical and geo-environmental engineering. Graduate students are encouraged to acquire a broad knowledge base by combining both experimental and analytical aspects in their research, as well as working on projects with other faculty outside their thesis or dissertation topics. Development of a graduate level course called "Environmental Geotechnology", which can also be taken as a professional elective by undergraduate students, emphasizes the importance of geotechnical issues in solving environmental problems. ***