Wave-in-Deck Forces on Offshore Platforms

2000 ◽  
Vol 123 (1) ◽  
pp. 10-21 ◽  
Author(s):  
R. G. Bea ◽  
R. Iversen ◽  
T. Xu
Keyword(s):  
Laboratory Test ◽  
Field Performance ◽  
Wave Force ◽  
Green Water ◽  
Extreme Condition ◽  
Wave Crest ◽  
Wave Forces ◽  
Offshore Platforms ◽  
Laboratory Test Results ◽  
Storm Wave

The extreme condition storm wave crest heights for many older platforms indicate that there would be “green water” in the lower decks. The API guidelines to determine wave forces acting on the decks of these platforms indicate that most platforms cannot survive such loadings. The decks must either be removed or the decks raised to clear the specified wave crests. A variety of laboratory tests have been performed to address this problem. Several approaches have been developed to compute the wave crest loadings and the responses of the platforms to the loadings. There have been many instances in which platforms have experienced significant wave loadings in their lower decks during hurricanes. Some of these platforms have survived and some have failed. This paper summarizes results from a study of laboratory test results and the performance of platforms in the Gulf of Mexico that have survived and failed during hurricane wave loadings in their decks. Modifications to the API deck wave force guidelines are discussed and validated with laboratory test data and platform field performance during hurricanes.

Effect of Seabed Slope on Offshore Pile Lateral Behaviour Under Wave Force

2010 ◽  
Author(s):  
Sathyanarayanan Dhandapani ◽  
Muthukkumaran Kasinathan
Keyword(s):  
Finite Element ◽  
Vertical Direction ◽  
Pile Group ◽  
Element Model ◽  
Wave Force ◽  
Wave Forces ◽  
Extreme Conditions ◽  
Offshore Platforms ◽  
Wave Loads ◽  
Offshore Structure

Fixed offshore platforms supported by pile foundations are required to resist dynamic lateral loading due to wave forces. The response of a jacket offshore tower is affected by the flexibility and nonlinear behavior of the supporting piles. In this study, a typical fixed offshore platform is chosen, and dynamic wave analysis is performed on it. Analysis has been performed for normal environmental conditions and extreme conditions. For the foundation, the deflections and reactions at regular intervals along the vertical direction from the seabed have been found out from the dynamic analysis, and the results have been compared for normal and extreme conditions. The aim of this study is to investigate the effects of the combined lateral and vertical loads on pile group foundation of a fixed offshore structure and the effects of seabed slope on the pile responses. To provide a more accurate and effective design for offshore pile foundation systems under axial structural loads and lateral wave loads, a finite element model which is modelled in FLAC3D is employed herein to determine the soil structure interaction under similar loading conditions. Three dimensional modelling and the analyses are done using FLAC3D — a finite element package.

scholarly journals Computational Methods for Moving and Deforming Objects in Extreme Waves

2019 ◽  
Author(s):  
Arthur E. P. Veldman ◽  
Henk Seubers ◽  
Matin Hosseini ◽  
Xing Chang ◽  
Peter R. Wellens ◽  
...  
Keyword(s):  
Well Being ◽  
Simulation Method ◽  
Engineering Problem ◽  
The Body ◽  
Green Water ◽  
Wave Forces ◽  
Offshore Platforms ◽  
Wave Loads ◽  
Floating Platform ◽  
Offshore Industry

Abstract Wave forces can form a serious threat to offshore platforms and ships. The damage produced by these forces of nature jeopardizes their operability as well as the well-being of their crews. Similar remarks apply to coastal defense systems. To develop the knowledge needed to safely design these constructions, in close cooperation with MARIN and the offshore industry the numerical simulation method ComFLOW is being developed. So far, its development was focussed on predicting wave loads (green water, slamming) on fixed structures, and for those applications the method is already being used successfully by the offshore industry. Often, the investigated object (ship, floating platform) is dynamically moving under the influence of these wave forces, and its hydrodynamic loading depends upon the position of the object with respect to the oncoming waves. Predicting the position (and deformation) of the body is an integral part of the (scientific and engineering) problem. The paper will give an overview of the algorithmic developments necessary to describe the above-mentioned physical phenomena. In particular attention will be paid to fluid-solid body and fluid-structure interaction and non-reflecting outflow boundary conditions. Several illustrations including validation, will demonstrate the prediction capabilities of the simulation method.

The Concept of the Optimum Alignment of Discharge Pipelines Due to the Minimization of the Wave Forces

1992 ◽  
Vol 25 (9) ◽  
pp. 211-216
Author(s):  
A. Akyarli ◽  
Y. Arisoy
Keyword(s):  
Wave Height ◽  
Wave Force ◽  
Wave Forces ◽  
Wave Direction ◽  
Incoming Wave ◽  
Pipeline Route ◽  
Optimum Alignment ◽  
The Cost ◽  
Resultant Wave

As the wave forces are the function of the wave height, period and the angle between the incoming wave direction and the axis of the discharge pipeline, the resultant wave force is directly related to the alignment of the pipeline. In this paper, a method is explained to determine an optimum pipeline route for which the resultant wave force becomes minimum and hence, the cost of the constructive measures may decrease. Also, the application of this method is submitted through a case study.

Effect of Ibuprofen on Serum Laboratory Test Results

1983 ◽  
Vol 40 (6) ◽  
pp. 1025-1034
Author(s):  
Carol L. Colvin ◽  
Raymond J. Townsend ◽  
William R. Gillespie ◽  
Kenneth S. Albert
Keyword(s):  
Laboratory Test ◽  
Test Results ◽  
Laboratory Test Results

scholarly journals Characteristics of Breaking Wave Forces on Piles over a Permeable Seabed

2021 ◽  
Vol 9 (5) ◽  
pp. 520
Author(s):  
Zhenyu Liu ◽  
Zhen Guo ◽  
Yuzhe Dou ◽  
Fanyu Zeng
Keyword(s):  
Wave Breaking ◽  
Stokes Equations ◽  
Slope Angle ◽  
Wave Force ◽  
Breaking Waves ◽  
Offshore Wind ◽  
Secondary Wave ◽  
Wave Forces ◽  
Breaking Wave ◽  
Breaking Wave Forces

Most offshore wind turbines are installed in shallow water and exposed to breaking waves. Previous numerical studies focusing on breaking wave forces generally ignored the seabed permeability. In this paper, a numerical model based on Volume-Averaged Reynolds Averaged Navier–Stokes equations (VARANS) is employed to reveal the process of a solitary wave interacting with a rigid pile over a permeable slope. Through applying the Forchheimer saturated drag equation, effects of seabed permeability on fluid motions are simulated. The reliability of the present model is verified by comparisons between experimentally obtained data and the numerical results. Further, 190 cases are simulated and the effects of different parameters on breaking wave forces on the pile are studied systematically. Results indicate that over a permeable seabed, the maximum breaking wave forces can occur not only when waves break just before the pile, but also when a “secondary wave wall” slams against the pile, after wave breaking. With the initial wave height increasing, breaking wave forces will increase, but the growth can decrease as the slope angle and permeability increase. For inclined piles around the wave breaking point, the maximum breaking wave force usually occurs with an inclination angle of α = −22.5° or 0°.

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