The configuration of braces has a considerable influence in the lateral behavior of pile supported steel jacket type offshore platforms. In this paper nonlinear static push over analyses and hysteresis curves are used to investigate lateral behavior of a jacket type offshore platform considering different configurations for vertical bracings of the jacket. One sample platform, constructed in Persian Gulf, is precisely modeled using the finite element program Opensees. Since the lateral response of offshore platforms is completely dependent on their foundations' behavior, an accurate model is used for modeling the foundation of this structure. Soil-pile-structure interaction is considered using Beam on Nonlinear Winkler Foundation model (BNWF). Lateral and vertical soil stiffness and end bearing were considered using p-y, t-z and q-z nonlinear models, respectively. Moreover, the buckling behavior of the braces is considered in the simulation of the platform to consider the behavior of the platform after buckling, and redistribution of the shear forces in the structure due to the bracings failures. The structure was modeled using nonlinear beam-column elements which have the ability to consider the spread of plasticity along the elements. The sections used for elements are fiber sections which are suitable for considering composite section of pile-grout-leg.
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