Modeling Quasi-Elastic Properties of Sand while considering Inherent and Stress-Induced Anisotropies

Abstract

The hypoelastic model (HongNam and Koseki, 2005)−which can describe inherent and stress-induced anisotropies in the quasielastic properties of sand subjected to cyclic triaxial and torsional loadings−was modified to more rationally evaluate the elastic components of sand in the general three-dimensional stress state. In the new simulation, the compliance matrix that links the stress and elastic strain increments in the principal stress axes was formulated symmetrically, as required by the law of thermodynamics. Comparisons between the simulation results and experimental data showed that the modified model could effectively simulate the experimental data values. Note that differences between the simulated values of compliance matrix [M] in the material axes obtained by both models were generally small within the employed stress paths, except the M26 and M62 values. The effect of inherent anisotropy on quasi-elastic components of the compliance matrix in the material axes was generally small at low shear stress ratio values (τzθ/σ′θ) during torsional loading from the isotropic stress state, and increased at larger shear stress ratio values, especially during torsional loading from the anisotropic stress state.