9502530 Boulanger The objective of this research project is to develop a fundamental framework for understanding and describing the behavior of "liquefiable" fine-grained soils subjected to cyclic and monotonic undrained loading -- a necessary step in the development of reliable design methodologies for assessing liquefaction potential of soils. The term "liquefiable" is used to denote fine-grained soils that would be considered susceptible to severe strength loss during earthquake loading. The primary task towards achieving this objective is a comprehensive laboratory study of select low-plasticity silts and clays over the wide range of conditions necessary to establish a fundamental framework. The project includes monotonic loading, cyclic loading, post-cyclic monotonic loading, and consolidation tests over a wide range of confining stresses and void ratios to investigate the interrelationships between the undrained loading behavior and the conditions of initial state, quasi-steady state, and steady state. It also includes an investigation of the influence of sample preparation method, stress history, and loading path (i.e., triaxial versus torsional shear) over a wide range of void ratios and confining stresses The results of this study will fill a vital gap in the understanding of the behavior of fine-grained soils during earthquake loading, and thereby assist in the development of engineering procedures for assessing potential earthquake hazards related to the earthquake loading response of fine-grained soils. EDUCATION PLAN The objective of the education plan is to equip civil engineering students with a sound philosophy of engineering, a rigorous grounding in engineering basics and fundamentals, and an appreciation of the complementary roles of theory and judgment. The education plan covers several details which will enhance the basic strength of the existing curriculum, and thereby contribute to an inspiring, well-rounded education in civil and environmental engineering. It includes the following items: In design courses, have a practicing professional assist in setting up the design project, and then discuss alternative designs at the end of the course; select these and other new course projects to illustrate the complementary roles of fundamental theory and engineering judgment in the practice of civil and environmental engineering; develop an instructional video on drilling and sampling procedures for site characterization; introduce computer- based data-acquisition systems into the undergraduate laboratory curriculum; involve undergraduates in research projects via summer employment and independent research electives; and introduce results from recent research in appropriate courses ***
