NONLINEAR SOIL-STRUCTURE INTERACTION ANALYSIS OF ONE-, TWO-, AND THREE-DIMENSIONAL PROBLEMS USING FINITE-ELEMENT METHOD

Finite element procedures are developed for analysis of stress-deformation problems for one-, two-, and three-dimensional idealizations including nonlinearities due to material behavior and interaction effects; soil-structure interaction is simulated by using a special interface element. Improved and consistent computational algorithms are developed by combining incremental and iterative techniques for handling material nonlinearities. Interaction in one-dimensional problems are handled by using a stress-transfer technique; foundation is characterized by using a Ramberg-Osgood model.;Different constitutive laws based on Variable Moduli, Drucker-Prager, critical state and cap models are implemented in two- and three-dimensional procedures. Here, special attention has been given to the theory and derivation of constitutive equations based on plasticity theory. Material parameters for a granular soil are determined from appropriate laboratory tests. A number of examples involving one-, two-, and three-dimensional problems such as laboratory test specimens, footings and beams have been analyzed by using the procedures in order to verify the formulations and codes. Verification is considered highly satisfactory. A complex problem involving a track-support structure is then analyzed and the predictions are compared with actual field measurement.