Effect of Wave Loading on the Seismic Behavior of a Typical Fixed Jacket-Type Platform

Design of fixed offshore platforms to resist earthquakes involves many of the same problems and issues as other onshore structures. However, there are some important differences that the most important one is the presence of seawater. It influences the mass, stiffness, damping and strength characteristics of the platform, which can have important effects on the structure response characteristics. The entrained water inside the platform elements and the water that is accelerated by the motions of the structure, have very important effects on the mass and damping characteristics of the platform. The presence of other environmental loads, particularly waves can also influence the response of these structures. In this paper, the nonlinear response of a typical jacket type platform, which has been installed in Persian Gulf, under wave and earthquake loadings are studied. The structure is modeled by ANSYS, finite element software. Time histories of different earthquake loadings are applied. Wave characteristics are based on local information. These loadings are applied separately and simultaneously. Moreover, they are applied in the same direction and different directions. The results are compared with each other and the most sever cases are extracted.