A finite element procedure is used for analysis of a number of soil-structure interaction problems. This procedure involves one dimensional beam-column element, two-dimensional (rectangular) plate element, and nonlinear foundation represented by a series of springs. The behavior of the latter is simulated by using a special form of the Ramberg-Osgood Model. The nonlinear analysis is performed by using an incremental iterative scheme. The procedure is used to predict behavior of a number of problems such as beams and plates on elastic and nonlinear foundations, building frame and foundation, and cap-pile-foundation interaction. The predictions are compared with closed form and laboratory observations. In the case of pile-cap-foundation analysis, a parametric study is performed to delineate the effects of the relative stiffness of the cap, pile and nonlinear soil. The comparisons between the predictions and observations has been found to be satisfactory. / Master of Science