A formulation for modeling soil-structure interaction has been presented. In conjunction with the formulation, a computer code was written to implement it. Several problems were analyzed to demonstrate the accuracy of the code. The program called SEQCON utilizes an eight-node isoparametric quadrilateral. An interface and tar element are also available. Four material models are used. They are the linear elastic, the hyperbolic, the trucker-Prager, and the cap model. Several construction sequence steps were modeled. They include in situ, dewatering, excavation, deposition (embankment) and tie-backs. The code itself is modular in design and quite flexible. It is easy to implement and to modify. / M.S.