Ultimate Load Capacity Analysis Of Fixed Offshore Platforms With Pushver Method

Most of the oil & gas platforms in iranian continental shelf are template (or jacket) type platforms. Large number of them have built about 2 or 3 decays ago, and they face damaged during their production life. Ild AB(ABOZAR) platform is one of them and it was demaged with missile attack during war. This article is looking forward to calculated load factor and force-displacement curve of this kind of platforms, using the nonlinear performance of the structure with pushover method. Offshore platforms nonlinear analysis is a part of IMR (Inspection, Maintenance & Repair) program and this article focuses on nonlinear analysis. SAP2000 and ANSYS5.4 are two finite element softwares wich used to verify results, and also some simple examples are analysed and compared with other articles for this purpose. After verifying results successfully, new and old AB platforms are model with above mentiond softwares, then pushover analysis is performed in the following cases: platforms are intact, old AB in demage position, performing some other demages on platforms, effect of load pattern on platform behavior and also considering poil interaction. In all above mentiond cases displacement versus load curves are plotted also the results are discussed.

Keywords:

template type platforms , pushover analysis , ultimate load capacity , load factor , nonlinear analysis