ELASTIC-PLASTIC ANALYSIS OF FOOTINGS ON ANISOTROPIC SOILS

A constitutive model using multiple yield surfaces is developed for analyzing foundation problems on anisotropic soils. The model parameters are obtained from simple triaxial test data and a close model prediction compared to the experimental data for two different soils are obtained. A nonlinear finite element analysis of two‐dimensional plane strain footings and three‐dimensional footings is done and the influence of anisotropy on the bearing capacity and settlement are studied. For the range of anisotropy encountered in the field, the bearing capacity and settlements for anisotropic soils can differ by over 100% compared to the isotropic case. Anisotropy has the largest influence in strip footings and the lesser in square footings. The constitutive model developed is simple in form and easy to use and yet very general to accommodate the complex anisotropy of the soils.