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. ***
