development of a numerical model which describes launching of offshore jackets from barge is presented in this paper. in this model, in addition to capabilities of commercial softwares, water entry forces on jacket members and an implicit newmark solution technique are included. the results are in general agreement with other numerical software’s available (sacs). fluid forces acting on jacket ...

offshore jacket-type towers are steel structures designed and constructed in marine environments for various purposes such as oil exploration and exploitation units, oceanographic research, and undersea testing. in this paper a newly developed meta-heuristic algorithm, namely cyclical parthenogenesis algorithm (cpa), is utilized for sizing optimization of a jacket-type offshore structure. the a...

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. ...

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...

Physical model tests with the scale of 1:36 are carried out in the Near-Shore Wave Basin (NSWB) at Tainan Hydraulics Laboratory (THL) with the jacket-type offshore wind turbine foundation (jacket-type foundation) and the combination of hard or soft scour protection in the test area. Scouring around the jacket-type foundation exposed to wave and current was conducted in the NSWB with a mobile be...

Offshore jacket-type towers are steel structures designed and constructed in marine environments for various purposes such as oil exploration and exploitation units, oceanographic research, and undersea testing. In this paper a newly developed meta-heuristic algorithm, namely Cyclical Parthenogenesis Algorithm (CPA), is utilized for sizing optimization of a jacket-type offshore structure. The a...

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...

This study focused on investigating various existing types of offshore jacket substructures along with a proposed twisted-tripod jacket type (modified jacket (MJ)-structures). The architectures of the three-leg structure, as well as the patented twisted jacket structure motivated the design of the proposed MJ-structures. The dimensions of the structures were designed iteratively using static st...

Structural optimization of offshore wind turbine structures has become an important issue in the past years due to the noticeable developments in offshore wind industry. However, considering the offshore wind turbines’ size and environment, this task is outstandingly difficult. To overcome this barrier, in this paper, a metaheuristic algorithm called Enhanced Colliding Bodies Optimization...

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...