Y Komachi - Department of Civil Engineering, Pardis Branch, Islamic Azad University, Pardis, Iran
M. R Tabeshpour - Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran

Some existing platforms may have some aspects of deficiency in both seismic and fatigue issues. From economic point of view it is preferable to retrofit and continue using of existing jackets in many cases, in comparison to a new installation. In this paper a relatively complete review has been carried out on various methods of rehabilitation. As an example an existing 4-leg service platform placed in the Persian gulf (Ressalat) is considered and the results are presented. Some efficient rehabilitation methods such as Friction Damper Device (FDD) and Buckling Restrained Braces (BRB) are presented and investigated for seismic loads and near-field effects as well. In this paper far and near field earthquakes are considered as possible excitations and the effects of FDD and BRB on the structural behavior are investigated numerically. The results show the high efficiency of both two methods in reduction structural responses and increasing seismic performance level.

Jacket Offshore Platform, Rehabilitation, FDD, TMD