the sirri jacket offshore platform was designed and installed in persian gulf of iran in 1975 and has been in service since that time. the importance of offshore structure's stability and the failure of this kind of structure during an earthquake in different active zones revealed that earthquake loading has to be considered. in this paper, magnetorheological (mr) fluid dampers have been propos...

The Sirri jacket offshore platform was designed and installed in Persian gulf of Iran in 1975 and has been in service since that time. The importance of offshore structure's stability and the failure of this kind of structure during an earthquake in different active zones revealed that earthquake loading has to be considered. In this paper, Magnetorheological (MR) fluid dampers have been propos...

Offshore structures such as jacket platforms have to inevitably be designed against  sever  environmental actions. In seismically active areas these structures also become susceptible to earthquake excitations. Strong ground motions recorded  in recent earthquakes, including the 1995 Kobe, Japan, 1999 Chi-chi, Taiwan and 1999 Kocaeli, Turkey earthquakes, revealed that the dynamic motions in nea...

In offshore structures, most of failures are caused by the lack of sufficient piles strength. Scour phenomena affects the load transition and the pile strength. The necessity of the consideration of scouring phenomena amplifies when the scour depth becomes remarkable, which can endanger the jacket stability. In this paper, a new method is used to consider the pile scouring using nonlinear pusho...

Regarding the previous earthquake damages in offshore structures, as vital structures in the oil and gas industries, it is important that their seismic design will be performed with very high reliability. Accepting the Nonlinear Time History Analyses (NLTHA) as the most reliable seismic analysis method, in this paper an offshore platform of jacket type with the height of 304 feet and with a dec...

Most of oil and gas offshore platforms are located in the seismic regains. So, Seismic vulnerability evaluation of the offshore platforms is one of the most important and vital issues in the structural systems. In this study, jacket type offshore platforms are studied by incorporating the pushover analyses and nonlinear time history analyses, in such a way that, first some push over analyses ar...

1.1 Offshore Structures: Offshore structures used for oil and gas extraction have the common function of providing a safe, dry working environment for the equipment and persons those operates the platform. Jacket supported drilling equipment as a guide for the piled foundations. The substructure referred to as the jacket is a three dimensional space frame made from large tubular steel members. ...

In the structural optimization problem, the aim is to decrease the amount of structural costs and weight, but the safety of platform should not violate the individual limits enforced by offshore codes. The outer diameter and thickness of members are two important variables in the optimization process and their final dimensions should be obtained according to the optimization algorithms such as ...

Installation of jacket platforms requires simultaneous and combined operations multiple assets. Once the whole process has to be planned, it is necessary predict in a fast reliable way possible weather limitations that may occur during operations. The paper will present major challenges this unusual innovative Dynamic Positioning analysis which been carried out for Ana Jacket installation. obta...