Stresses and Displacements in Cross-Anisotropic Soils

An analytic investigation is presented on the effect of soil cross-anistropy on surface displacements and stress distributions in a homogeneous thick soil deposit (halfspace) subjected to axisymmetric parabolic vertical surface loading. Rigorous treatment is given to deformational soil anisotropy and particular emphasis is accorded to the sensitivity of calculated stresses and deformations to assumed realistic values of the five independent material constants, under both drained and undrained loading conditions. For a given vertical Young's modulus, it is found that the horizontal Young's modulus, the shear modulus on vertical planes and the Poisson's ratio for horizontal due to vertical strain have a profound effect on all stress and displacement components, especially under undrained conditions. The dependence of normal vertical stresses on material properties and particularly on one of the Poisson's ratios disproves the opposite conclusion of isotropic elasticity.