Quantitative Analysis of Microstructure Properties and their Influence on Macroscale Response.

The shear behavior of soils is typically related to the state of the soil in terms of the initial global void ratio and effective confining stress. However, laboratory tests on reconstituted sand specimens have shown that the shear behavior is also dependent upon the specimen preparation method. This paper describes the findings of a series of studies, which quantitatively evaluated the differences in the inherent microstructure of dilatant sand specimens prepared by air pluviation, moist tamping and water deposition. Quantitative measures such as local void ratio distribution, local void ratio distribution entropy and particle orientation entropy were found to be dependent on the preparation method. Microstructure evolution in the sand specimens during triaxial compression testing was also investigated. Measuring global properties of the specimens was shown to mask the complex and evolving internal conditions during shear. The global response was found to be strongly dependent on the shear induced microstructure which in turn was directly influenced by the preparation method dependent inherent microstructure. [ABSTRACT FROM AUTHOR]