• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.722-740
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• 2005

본 논문은 최근의 석유탐사 및 개발사업 현장에서 사용되고 있는 최신의 측량기술 및 해양공사의 측량 기술 표준화 동향을 소개하고, 이에 기반하여 동해1 가스전 해저배관 공사에 적용한 사례를 기술하였다. 해저배관 시설공사를 수행하기 위한 사전측량 및 시공지원 측량은 다양한 탐사장비가 동원되며, 각 장비들의 운영, 자료처리, 해석, 도면화를 위하여 실시간지원이 가능한 시스템을 운영하는 기술이 요구된다. 이를 위하여 해저배관 시공단계별(Pre-Installation Survey, Touch-down Monitoring, As-laid As-Built Survey, Post-installation Survey) 요구되는 측량성과 및 이를 획득하기 위한 소해측량 시스템의 성능평가 및 정확도 분석을 수행하였다. 또한, 해저지형 탐사를 위해 동원된 소해측량시스템(Swath Sonar System)에서 취득되는 수심(Bathymetry) 및 후방산란 음압(Backscattered Amplitude) 자료를 맵핑하여 해저배관의 설치 경로를 측량하는 기법에 대하여 소개하고, 추후 해저배관 보호 및 관리시의 효율적인 모니터링 기법을 제시한다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.10
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• pp.1131-1137
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• 2012

Subsea pipelines have been operated with buried depths of 1.2-4m underneath the seabed to prevent buoyancy and external impacts. Therefore, they have to show resistance to both the soil load and the hydrostatic pressure. In this study, the structural integrity of a subsea pipeline subjected to soil load and hydrostatic pressure was evaluated by using FE analyses. A parametric study showed that the internal pressure increased the plastic collapse depth by increasing the resistance to plastic collapse. The hoop stress increased with an increase in the buried depth for the same water depth; however, the hoop stress decreased with an increase in the water depth for the same buried depth.

• Journal of the Korean Institute of Gas
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• v.14 no.4
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• pp.45-50
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• 2010

The marine pipelines laid in deep waters were evaluated to verify the resistance on the plastic collapse to heavy ambient external pressure due to hydrostatic pressure. In this study, the plastic collapse behavior of the marine pipe subjected to hydrostatic pressure was evaluated with the ovality and ratio of diameter to thickness in FE analyses. A parametric study was shown that the internal pressure increased the plastic collapse depth by increasing of the resistance to the plastic collapse. It was also shown that the collapse depth of the pipeline having a local ovality was deeper than that of the pipeline having a global ovality. Finally, the plastic collapse depth decreased when either the ratio of diameter to thickness or the ovality increased.

• Journal of the KSME
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• v.54 no.1
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• pp.48-52
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• 2014

배관 설계 및 시공은 경제적이고 안전해야 하며 이를 위해서는 신뢰성 있는 자료에 근거하여 기술적 검토와 연구가 수행되어야 한다. 이 글에서는 가스배관을 해저에 건설할 때 설계 시 고려해야 할 사항 및 시공기술에 대한 현황을 소개하고자 한다.

• Journal of the Korean Society for Marine Environment & Energy
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• v.6 no.2
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• pp.54-62
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• 2003

The free span of a subsea pipeline due to seabed scouring can result in structural failure by severe ocean environmental loads and vortex induced vibrations. This Paper examines the safety of subsea pipelines with free spans under axial compressive load. The variation of allowable lengths of static and dynamic free spans is examined for generalized boundary conditions. The free span is modelled as a beam with an elastic foundations and the boundary condition is replaced by linear and rotational springs at each end. The static and dynamic free span curves are obtained with a function of non-dimensional parameters. A case study is carried out to introduce the application method of the curve. The results of this study can be usefully applied for the design of subsea pipelines with a free span.

• Journal of the Korean Institute of Gas
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• v.15 no.6
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• pp.14-19
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• 2011

The objective of this study was to investigate the effect of the thickness eccentricity on the collapse pressure of a subsea pipeline subjected to external pressure. The collapse behavior of the subsea pipeline containing initial imperfection was evaluated using elastic-plastic finite element (FE) analyses. API 5L X65 and API 5L X80 Pipelines with the thickness eccentricity values between 4~16% were adopted to investigate the plastic collapse under hydrostatic pressure. A parametric study was shown that the plastic collapse pressure decreased when either the thickness eccentricity or the ratio of diameter to thickness increased.

• Journal of the Korean Institute of Gas
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• v.5 no.4 s.16
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• pp.21-26
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• 2001

Because of the continuous growth of energy consumption, and also tile tendency to site power lines and pipelines along the same routes, the close proximity of high voltage structures and metallic pipelines has become more and more frequent. Recently, the results of assessment about a system integrity are needed in korea also when a gas pipeline is running parallel with high voltage power line in same submarine tunnel, Therefore, we analyze the system integrity(AC corrosion of pipe, melting of pipeline coating, safety of insulation flange, especially cathodic protection system which are rectifier and CI(cathodic Isolator)) resulting from the influence of high voltage power system.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.10a
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• pp.20-25
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• 2002

본 논문은 대 변형 굽힘에 의한 소성 모멘트의 계산시 ovality를 고려한 파이프의 중립축에 대한 모멘트에 관해 논한다. 기존의 계산방법에 의한 중립축에 대한 모멘트 계산결과와 새로운 방법에 의한 계산결과를 비교해 보았다. 파이프가 길이방향의 모멘트에 의하여 굽어질 때, 증가하는 모멘트에 따른 ovality 변화를 고려하여 중립축에 대한 모멘트 계산에 적용해 보았다. 모멘트 계산은 타원형의 파이프 단면을 미세한 단면으로 나누어서 각 단면에 대한 응력을 비선형 strain-stress 식을 이용하여 구한 다음 중립축에 대해 계산을 수행하였다. 대 변형 굽힘에서 일어나는 실제현상 중 하나인 ovality를 파이프의 계산에 적용함으로써 좀 더 정확한 중립축에 대한 모멘트를 계산할 수 있었다. 이 방법을 reel에 의한 해저배관의 설치 공법에서 사용되는 reverse bending radius 계산에 적용해 보았다.

• 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.

• Spatial Information Research
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• v.17 no.1
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• pp.103-115
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• 2009

Recently, the seabed facility is gradually being increased based on the development of harbor and the coastal area. However, the comparison between the survey data with the chart still shows the significant differences leading to various disasters over sea accident. Therefore, in this study, the investigation on the seabed facility were performed in 5 areas through an accuracy analysis using an up-to-date surveying equipment(MBES, SSS and SBP). Based on the study more systematic management on the seabed facility, more accurate method on the surveying, and some considerations on the related policies are suggested. Through the study, we obtained more accurate measurement on depth and seabed piping forms in Jakdo and Pyong-tack, on sunken ship in a Mok-po, on seabed crater in Je-ju. In addition, it was possible to present the method for the construction of information infra and a connection with the seabed facility. The criteria on the equipment's specification, surveying method and procedures are set by the experiments and the investigation and surveying accuracy on the seabed facilities are also suggested.