• Journal of Ocean Engineering and Technology
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• v.21 no.1 s.74
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• pp.31-39
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• 2007

Recently, the nonlinear dynamic responses among waves, submarine pipeline and seabed have become a target of analyses for marine geotechnical and coastal engineers. Specifically, the velocity field around the submarine pipeline and the wave-induced responses of soil, such as stress and strain inside seabed, have been recognized as dominant factors in discussing the stability of submarine pipeline. The aim of this paper is to investigate nonlinear dynamic responses of soil in seabed, around submarine pipeline, under wave loading. In order to examine wave-induced soil responses, first, the calculation is conducted in the whole domain, including wave field and the seabed, using the VOF-FDM method. Then, velocities and pressures, which are obtained on the boundary between the wave field and the seabed, are used as the boundary condition to compute the wave-induced stress and strain inside seabed, using the poro-elastic FEM model, which is based on the approximation of the Biot's equations. Based on the numerical results, the characteristics of wave-induced soil responses around submarine pipeline are investigated, in detail, inrelation to relative separate distance of the submarine pipeline from seabed. Also, the velocity field around the submarine pipeline is discussed.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.6
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• pp.599-609
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• 2017

Desalination plants have been recently constructed in many parts of the world due to water scarcity caused by population growth, industrialization and climate change. Most seawater desalination plants are designed with a submarine pipeline for intake and discharge. Submarine pipelines are installed directly on the bottom of the water body if the bottom is sandy and flat. Intake is located on a low-energy shoreline with minimal exposure to beach erosion, heavy storms, typhoons, tsunamis, or strong underwater currents. Typically, HDPE (High Density Polyethylene) pipes are used in such a configuration. Submarine pipelines cause many problems when they are not properly designed; HDPE pipelines can be floated or exposed to strong currents and wind or tidal action. This study examines the optimal design method for the trench depth of pipeline, analysis of on-bottom stability and dilution of the concentrate based on the desalination plant conducted at the Pacific coast of Peru, Chilca. As a result of this study, the submarine pipeline should be trenched at least below 1.8 m. The same direction of pipeline with the main wind is a key factor to achieve economic stability. The concentrate should be discharged as much as high position to yield high dilution rate.

• Ocean Systems Engineering
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• v.9 no.2
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• pp.135-155
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• 2019

One of the safest and the most economical methods to transfer oil and gas is pipeline system. Prediction and prevention of pipeline failures during its assessed lifecycle has considerable importance. The dropped object is one of the accidental scenarios in the failure of the submarine pipelines. In this paper, using Monte Carlo Sampling, the probability of damage to a submarine pipeline due to a box-shaped dropped object has been calculated in terms of dropped object impact frequency and energy transfer according to the DNV-RP-F107. Finally, Reliability sensitivity analysis considering random variables is carried out to determine the effect intensity of each parameter on damage probability. It is concluded that impact area and drag coefficient have the highest sensitivity and mass and add mass coefficient have the lowest sensitivity on probability of failure.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.346-348
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• 2001

This paper analyze the interference problems, especially AC corrosion when the gas pipeline is buried with power cable in the same submarine tunnel. This paper present the results of the study about AC corrosion, limitation of safety voltage, modeling of power cables, gas pipeline and grounding systems, analysis of induction voltage according to various circumstance, soil resistivity, length of tunnel. and so on.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.3
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• pp.176-185
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• 2003

In order to ensure that submarine pipelines are stable and functional during their project lives, attention must be paid to possibility of their local scouring. When a pipeline is placed on an erodible bed, scour will develop and cause the spanning of the pipeline. U they were destroyed partially or fully, it might cause enormous restoration expenses and contamination of sea water. This paper aims at examining the characteristics of the scour End the prediction of the local scour depths around the submarine pipelines. The pipelines on the model beach with the uniform slope are placed, and the local scour depths around the pipelines are obtained according to the various wave steepnesses. Using the experimental results, some parameters needed for analyses are calculated. Finally, empirical equations of the scour depth around the pipelines are suggested through the correlation analyses between the rotative scour depth. the KC number and Modified Ursell number.

• Ocean Systems Engineering
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• v.3 no.1
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• pp.9-34
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• 2013

Submarine pipelines encounter significant wave forces in shallow coastal waters due to the action of waves. In order to reduce such forces (also to protect the pipe against anchors and dropped objects) they are buried below the seabed. The wave force variation due to burial depends on the engineering characteristics of the sub soil like hydraulic conductivity and porosity, apart from the design environmental conditions. For a given wave condition, in certain type of soil, the wave force can reduce drastically with increased burial and in certain other type of soil, it may not. It is hence essential to understand how the wave forces vary in soils of different hydraulic conductivity. Based on physical model study, the wave forces on the buried pipeline model is assessed for a wide range of wave conditions, for different burial depths and for four types of cohesion-less soils, covering hydraulic conductivity in the range of 0.286 to 1.84 mm/s. It is found that for all the four soil types, the horizontal wave force reduces with increase in depth of burial, whereas the vertical force is high for half buried condition. Among the soils, well graded one is better for half buried case, since the least vertical force is experienced for this situation. It is found that uniformly graded and low hydraulic conductivity soil attracts the maximum vertical force for half buried case. A case study analysis is carried out and is reported. The results of this study are useful for submarine buried pipeline design.

• Journal of the Korean Professional Engineers Association
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• v.34 no.6
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• pp.55-59
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• 2001

• Journal of Ocean Engineering and Technology
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• v.8 no.2
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• pp.151-156
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• 1994

The equations of motion of a submarine pipeline with the internal flowing fluid and subject to hydrodynamic loadings are derived by using Hamilton's principle. Coupling between the bending and the longitudinal extension due to axial load and thermal expansion are considered. Coupling between the twisting and extension are not considered. The equations of motion are well agreed with the results which are derived by the vector method.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.10
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• pp.577-582
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• 2000

This paper analyze the interference problems, especially Ac corrosion when the gas pipeline is buried with power cable in the same submarine tunnel. This paper present the results of the study about interference mechanism(inductive coupling, conductive coupling, resistive coupling), AC corrosion, limitation of safety voltage, modeling of power cables, gas pipeline and grounding systems, analysis of induction voltage and optimal arrangement of power cables.

• 한국가스학회:학술대회논문집
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• 2001.10a
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• pp.108-113
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• 2001