These are my knowledge about anisotropy:
-It is claimed by Zdravkovic and Potts, that anisotropy possessed by soil is combination of
inherent anisotropy and
induced anisotropy.
The first one is the result of preferred particle orientation and variations in fabric, and have
influence on mechanical properties-elastic, plastic and failure behavior.
It can be measured by comparing strengths of specimens placed at various angles.
The second one in soil can exhibit whenever K0 is not equal to unity.
Combination of both components can be considered in K0-consolidated undrained test
corresponding to the stresses and sample orientation that will exist in in-situ.
In simple words its important to predict possible stress directions(principle and minor) in the field and to orientate specimens in test equipment according to these directions. And o f course its important to define what problem you want to solve.
You can find details in these articles:
-
Anisotropy and stress reorientation in clay by Dunncan & Chang 1966 (ASCE Journal of Soil Mechanica and Foundations Divisions)
-
Shear strength properties of two stratified clays, by Lo & Milligen 1967(ASCE Journal of Soil Mechanica and Foundations Divisions)
-
Variation in undrained shearing strength by semiconfined test, by DeLory & Lai 1971 (Canadian Geotech. Journal)
-
Strength anisotropy and time effects of two sensitive clay, by Lo & Morin 1972 (Canadian Geotech. Journal)
-Comparasion of undrained shear strength results obtain by different test methods in clays, by Eden & Law (Canadian Geotech. Journal)
-
Specimen preparation and liquefaction of sand, by Ladd 1974 (ASCE Journal of Geotechnical Engineering Division)
-
Elasto-plastic stress-strain theory for cohesionless soil with curved yield surface, by Ladd 1977 (International Journal of Solids and Structures)
-
Advances in modeling soil anisotropy, by Zdravkovic & Potts 1999(Springer, Berlin)
Some correlations between Undrained strength in vertical(Cuv) and horizontal (Cuh) directions by various researchers can be founded in the book
Excavations and Foundations in soft soil by Kempfert, and the above explanations of anisotropy are summerized in this book.
I hope I have helped a bit.
