Stress-Induced Anisotropic G m a x of Sands and Its Measurement

Anisotropy in elastic shear modulus Gma x exists in most soils as the result of either anisotropic soil fabric or anisotropic stress conditions. This paper presents a theoretical and experimental study on the anisotropy in a Gma x of sand due to a K0 stress condition. Elastic shear moduli of two types of sand in multiple stress planes under a K0 condition were measured using bender elements. Stress-induced anisotropy in Gma x of the sands during loading and unloading processes and the important influential factors were investigated. An empirical relationship for the estimation of K0 was proposed based on the experimental data. Shear moduli in nonprincipal stress planes were measured and compared with the results from the theory. The influence of stress cycles on Gma x in multiple stress planes was studied.