Fundamental properties of soils for complex dynamic loadings

An improved understanding of the fundamental behavior of soils under dynamic loads can lead to better modeling of many important soil and soil-structure phenomena. This report presents the initial results of a research program directed toward this goal. Constitutive modeling requirements are briefly reviewed, and results of a literature survey are summarized. A computer program for studying material models is described, and some preliminary examples are given. A study of insitu material behavior is presented in which several two-dimensional simulations of cylindrical Insitu Test (CIST) events were performed. Basic CIST phenomena are investigated, as well as the response of specific soils. Insitu shear behavior and effective stress modeling of soils is discussed.