Analysis of laboratory test data to derive soil constitutive properties
Jackson, J. G. (John Guy)
Miscellaneous PaperAbstract: Computer codes used in the solution of free-field ground shock problems are based on mathematically defined constitutive models. Quantitative input for these constitutive models is primarily based on laboratory test data, but extensive analysis and numerous assumptions are required to convert these data to a from suitable for actual code input. This report presents a detailed illustration of the analyses involved in deriving the soil constitutive properties required for a specific code formulation using laboratory test data from just one stratum of a single site. Data are available from static and dynamic uniaxial strain and triaxial shear tests; code property requirements are for mathematical expressions relating mean pressure to volumetric strain, Poisson's ratio to mean pressure, and a plastic yield criterion to mean pressure. The illustration indicates that progress is being made in developing mathematical constitutive models that are realistic in terms of actual physical behavior, but that if many of the assumptions presently being made in soil property analyses are to be eliminated, additional soil tests and measurements must be developed. The illustration also raises questions as to the validity of models based on a constant Poisson's ratio or a constant shear modulus and suggests that the behavior of the various models be carefully examined under different states and paths of stress.
U.S. Army Engineer Waterways Experiment Station.Engineer Research and Development Center (U.S.)
Ground shock; Shock waves; Blast effects; Soil mechanics; Mathematical models; Numerical models; Soil properties; Soil tests
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