Effect of foundation behaviour on steel jacket offshore platform failure modes under wave loading

2018 ◽  
Vol 14 (6) ◽  
pp. 570-581 ◽  
Author(s):  
Behrouz Asgarian ◽  
Mohamad Zarrin ◽  
Mojdeh Sabzeghabaian
Keyword(s):  
Failure Modes ◽  
Offshore Platform ◽  
Wave Loading ◽  
Steel Jacket ◽  
Jacket Offshore Platform

scholarly journals Effects of Redundancy in Bracing Systems on the Fragility Curve Development of Steel Jacket Offshore Platform

2019 ◽  
Vol 23 (1) ◽  
pp. 123-133 ◽  
Author(s):  
Md Samdani Azad ◽  
Wonsiri Punurai ◽  
Chana Sinsabvarodom ◽  
Pornpong Asavadorndeja
Keyword(s):  
Offshore Platform ◽  
Fragility Curve ◽  
Steel Jacket ◽  
Jacket Offshore Platform

scholarly journals Experimental Research on Reinforced Concrete Columns Strengthened with Steel Jacket and Concrete Infill

2021 ◽  
Vol 11 (9) ◽  
pp. 4043
Author(s):  
Aleksandar Landović ◽  
Miroslav Bešević
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Cross Section ◽  
Experimental Research ◽  
Failure Modes ◽  
Steel Tube ◽  
Rc Columns ◽  
Rc Column ◽  
Steel Jacket ◽  
Ductile Behavior

Experimental research on axially compressed columns made from reinforced concrete (RC) and RC columns strengthened with a steel jacket and additional fill concrete is presented in this paper. A premade squared cross-section RC column was placed inside a steel tube, and then the space between the column and the tube was filled with additional concrete. A total of fourteen stub axially compressed columns, including nine strengthened specimens and five plain reinforced concrete specimens, were experimentally tested. The main parameter that was varied in the experiment was the compressive strength of the filler concrete. Three different concrete compression strength classes were used. Test results showed that all three cross-section parts (the core column, the fill, and the steel jacket) worked together in the force-carrying process through all load levels, even if only the basic RC column was loaded. The strengthened columns exhibited pronounced ductile behavior compared to the plain RC columns. The influence of the test parameters on the axial compressive strength was investigated. In addition, the specimen failure modes, strain development, and load vs. deformation relations were registered. The applicability of three different design codes to predict the axial bearing capacity of the strengthened columns was also investigated.

Reliability Based Assessment of Deck Elevations for Offshore Jacket Platforms

2004 ◽  
Vol 126 (4) ◽  
pp. 331-336 ◽  
Author(s):  
Ernesto Heredia-Zavoni ◽  
Dante Campos ◽  
Gallegher Ramı´rez
Keyword(s):  
Reliability Index ◽  
Structural Reliability ◽  
Failure Modes ◽  
Probability Of Failure ◽  
Upper And Lower Bounds ◽  
Series System ◽  
Wave Loading ◽  
System Components ◽  
Storm Wave ◽  
Wave Heights

Structural reliability analyses of fixed marine platforms subjected to storm wave loading are performed to assess deck elevations. Platforms are modeled as a series system consisting of the deck and jacket bays. The structural reliability analyses are carried out assuming dominant failure modes for the system components. Upper and lower bounds of the probability of failure are computed. The variation of the reliability index per bay component as a function of wave height, with a focus on those wave heights that generate forces on the deck, is analyzed. A comparison is given for the deck probability of failure and the lower bound probability of failure of the jacket in order to assess how the deck or the jacket controls the probability of failure of the system. Results are also given for reliability analyses considering different deck elevations. Finally, an analysis of the total probabilities of failure, unconditioned on wave heights, is given.

Dynamic Analysis of an Offshore Platform With Excessive Vibration Under Wave Loading

2003 ◽  
Author(s):  
Chunyan Ji ◽  
Huajun Li ◽  
Shuqing Wang
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Dynamic Characteristics ◽  
Model Experiment ◽  
Offshore Platform ◽  
Normal Operation ◽  
Bohai Bay ◽  
Fe Modeling ◽  
Wave Loading ◽  
Relative Movement

An offshore platform of jacket type in Bohai Bay vibrates excessively under design environmental conditions, which has affected the normal operation of the platform. In order to mitigate the vibration of the platform, it is essential important to explore the cause of the vibration. So the objective of this study is to investigate the cause of the excessive vibration. In this paper, dynamic characteristics of the offshore platform are analyzed by numerical simulation using finite element (FE) modeling. To further verify the numerical results, a model experiment is conducted. Numerical and experimental results demonstrate that there are relative movement and impact between the piles and the jacket, i.e. the piles and the jacket didn’t connect well to an entity. It is this cause that the stiffness of the platform deceases and impact between piles and the jacket legs induce excessive vibration. And also the grouting measure is advised to reduce the vibration of the offshore platform according to the analysis results.

Study on Seismic Performance of Offshore Platform with Rocking Wall - TMD System

2014 ◽  
Vol 610 ◽  
pp. 78-83
Author(s):  
Ji Gang Zhang ◽  
Zhi Wei Jiang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Seismic Performance ◽  
Tuned Mass Damper ◽  
Offshore Platform ◽  
Element Analysis ◽  
Mass Damper ◽  
Jacket Offshore Platform ◽  
Rocking Wall ◽  
Wall System

Offshore platform rocking wall system and tuned mass damper are briefly introduced, and the paper integrates the advantages of these two kinds of seismic method, and the TMD is attached to the jacket offshore platform - rocking wall system, using the ANSYS for finite element analysis, and the analysis results are optimized. The results show that compared with the offshore platform - rocking wall system, additional TMD can give full play to the performances of the two kinds of seismic methods, which is remarkable.

Study on a magnetorheological elastomer-base device for offshore platform vibration control

2018 ◽  
Vol 30 (2) ◽  
pp. 243-255 ◽  
Author(s):  
Dingxin Leng ◽  
Haiyan Xiao ◽  
Lei Sun ◽  
Guijie Liu ◽  
Xiaojie Wang ◽  
...  
Keyword(s):  
Wave Spectrum ◽  
Offshore Platform ◽  
Random Wave ◽  
Offshore Platforms ◽  
Wave Loading ◽  
Magnetorheological Elastomer ◽  
Control Robustness ◽  
Resonance Control ◽  
Wave Induced ◽  
Strong Control

Wave loading is one of the leading factors contributing to fatigue damage of offshore platforms. Vibrations in marine platforms due to nonlinear hydrodynamic forces can reduce platform productivity, endanger safety, and affect serviceability. This article presents numerical evaluation of a magnetorheological elastomer device for wave-induced vibration reduction of offshore platform. Random wave loadings are estimated by wave spectrum analysis and Morison’s equations. By altering field-induced stiffness of magnetorheological elastomers and non-resonance control strategy, the wave-induced vibration of offshore platform is effectively reduced, and the magnetorheological elastomer device presents strong control robustness under various wave loadings. This work indicates that magnetorheological elastomer-base device may open a new insight for vibration mitigation of ocean structures.

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