• Title/Summary/Keyword: Underground pipeline

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Influence on Parallel Pipelines of Distributed ICCP Systems for Mitigation of DC Traction Interference (전철 간섭 대책용 분포형 외부전원시스템이 병행하는 배관에 미치는 영향)

  • Lee, H.G.;Ha, Y.C.;Ha, T.H.;Bae, J.H.;Kim, D.K.
    • Proceedings of the KIEE Conference
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    • 2005.10c
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    • pp.285-287
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    • 2005
  • When an underground pipeline runs parallel with DC traction systems, it suffers from DC traction interference. Because the train is fed by the substation through the overhead wire and return current back to the substation via the rails. If these return rails are poorly insulated from earth, DC current leak into the earth and can be picked up by nearby pipeline. It may bring about large-scale accidents even in cathodically protected systems. In this paper we analyze the influence on parallel pipelines of distributed ICCP(impressed current cathodic protection) systems for mitigation of DC traction interference using the simulation software CatPro.

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Anode Location of Distributed ICCP Systems for Mitigation of DC Traction Interference on Buried Pipelines (전철 간섭 대책용 분포형 외부전원시스템의 양극위치)

  • Lee, H.G.;Ha, T.H.;Ha, Y.C.;Bae, J.H.;Kim, D.K.
    • Proceedings of the KIEE Conference
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    • 2005.07b
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    • pp.1660-1662
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    • 2005
  • When an underground pipeline runs parallel with DC traction systems, it suffers from DC traction interference. Because the train is fed by the substation through the overhead wire and return current back to the substation via the rails. If these return rails are poorly insulated from earth, DC current leak into the earth and can be picked up by nearby pipeline. It may bring about large-scale accidents even in cathodically protected systems. In this paper we analyze the anode location of distributed impressed current cathodic protection systems for the mitigation of DC traction interference on buried pipelines using the simulation software CatPro. We can get a fix on the anode location.

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Analysis of the induced voltage on the GAS pipelines buried in parallel with 22.9kV distribution line (22.9kV 배전선로와 병행하는 가스배관의 유도성 유도전압 해석)

  • Lee, H.G.;Ha, T.H.;Bae, J.H.;Kim, D.K.
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.130-132
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    • 2002
  • Because of the continuous growth of energy consumption and also the tendency to site power lines and pipelines along the same route, the close proximity of power lines and buried metallic pipelines has become more and more frequent. Therefore there has been and still is a slowing concern about possible hazards resulting from the influence of power lines on metallic pipelines. Underground pipelines that run parallel to or in close proximity to power lines are subjected to induced voltages caused by the time-varying magnetic fields produced by the power line currents. The induced electro- motive force cause currents circulation in the pipeline and voltages between the pipeline and surrounding earth. This paper analyzes the induced voltage on the gas pipelines buried in parallel with 22.9kV distribution lines. Their magnitude depends on the length of parallelism and on the distance between distribution lines and pipeline.

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An Assessment Pipe Damage Probability of High Pressure Underground Pipeline in Industrial Estate (산업단지 고압매설배관의 손상확률 평가)

  • Kim, jin-jun;Rhie, Kwang-Won;Choi, hun-ung;Choi, ji-hun
    • Journal of the Korean Institute of Gas
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    • v.23 no.2
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    • pp.9-16
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    • 2019
  • The frequency of major accidents which has probability of occurrence at the high pressure underground pipeline of industrial estate such an Ulsan, Yeo-ju by the other construction such as an excavation work will be compared to city gas underground pipeline to derive the basic event by the FTA and present. Also, Observe and analyze the pipe damage impact factor such as an excavation frequency, patrol cycle. As a result, It contributes to the safety improvement of high pressure gas buried pipeline due to obtain importance and sensitivity of the pipe damge impact factors.

The Corrosion Control Method for the Stray Current of Subway on Underground Gas Pipeline (지하철의 표유전류에 대한 가스배관의 전식대책법)

  • Ha, Tae-Hyun;Lee, Hyun-Goo;Bae, Jeong-Hyo;Kim, Dae-Kyeong;Ha, Yoon-Cheol
    • Proceedings of the KIEE Conference
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    • 2003.11a
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    • pp.382-384
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    • 2003
  • In case of parallel running with underground gas pipeline and subway, stray current of subway makes a interference on gas pipeline. This interference is one of the reason of gas pipeline corrosion. So, the high speed response rectifier was developed in order to mitigate a interference. In this paper, the field test result of proposed rectifier is presented. The effect of an alternative in stead of the forced drainage system is also presented.

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Correlation Analysis of the Occurrence of Ground Subsidence According to the Density of Underground Pipelines (지중관로 매설 밀집도에 따른 지반함몰 발생 상관 분석)

  • Kim, Jinyoung;Kang, Jaemo;Choi, Changho
    • Journal of the Korean GEO-environmental Society
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    • v.22 no.11
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    • pp.23-29
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    • 2021
  • Recently, ground subsidence has been steadily occurring mainly in downtown areas, threatening the safety of citizens. Under the road, various underground facilities such as water supply pipe, sewage pipe, and communication pipe are buried. Due to the aging of these underground facilities and the reckless development of the underground, it is acting as a cause of ground subsidence. Although there is a result of analyzing the risk of ground subsidence according to the deterioration of the existing pipeline, there is no result of analyzing the risk of ground subsidence using the density of pipelines indicating ground disturbance. Therefore, in this study, the density of the underground space was analyzed using the data of six types of representative underground pipelines in Seoul, and a study was conducted on whether there is a correlation with the ground subsidence. As a result, it was found that the density of underground facilities is high in the area where the ground subsidence occurred, indicating that the density of pipelines have an effect on the ground subsidence.

Stability Analysis of Vertical Pipeline Subjected to Underground Excavation (지하공간 굴착에 따른 수직파이프 구조물의 안정성해석)

  • 김종우
    • Tunnel and Underground Space
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    • v.10 no.4
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    • pp.533-543
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    • 2000
  • Deformation behavior and stability of vertical pipeline subjected to underground excavation have been studied by means of numerical analysis. Vortical ground displacements cause the pipe to be compressed, while horizontal ones cause it to be bent. In that region the vertical pipeline meets with the induced compressive stress and bending stress. In addition horizontal rock stress subjected to underground excavation may press the tube in its radial direction and it finally produces the tangential stress of pipe. In this study active gas well system is considered as an example of vertical pipelines. Factor analysis has been conducted which has great influence on the pipeline behavior. Three case studies are investigated which have the different pillar widths and gas well locations in pillar. For example, where overburden depth is 237.5 m and thickness of coal seam is 2.5 m, chain pillar of 45.8 m width in the 3-entry longwall system is proved to maintain safely the outer casing of gas welt which is made of API-55 steel, 10$\frac{3}{4}$ in. diameter and 0.4 in. thickness. Finally an active gas well which was broken by longwall mining is analyzed, where the induced shear stress turn out to exceed the allowable stress of steel.

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A Mitigation Methode of DC Stray Current for Underground Metallic Structures in KOREA (국가 기간 시설물의 전식 대책(안))

  • Bae, Jeong-Hyo;Ha, Yoon-Cheol;Ha, Tae-Hyun;Lee, Hyun-Goo;Kim, Dae-Kyeong
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1609-1611
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    • 2007
  • The owner of underground metallic structures (gas pipeline, oil pipeline, water pipeline, etc) has a burden of responsibility for the corrosion protection in order to prevent big accidents like gas explosion, soil pollution, leakage and so on. So far, Cathodic Protection(CP) technology have been implemented for protection of underground systems. The stray current from DC subway system in Korea has affected the cathodic protection (CP) system of the buried pipelines adjacent to the railroads. In this aspect, KERI has developed a various mitigation method, drainage system through steel bar under the rail, a stray current gathering mesh system, insulation method between yard and main line, distributed ICCP(Impressed Current Cathodic System), High speed response rectifier, restrictive drainage system, Boding ICCP system. In this paper, the mechanism of mitigation method of DC stray current for underground metallic structures is described.

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Transient Ground Deformation induced by Sequential Earthquakes and Estimation of Underground Water Pipeline Performance in Canterbury, New Zealand (뉴질랜드 캔터배리 지역 연속지진에 의해 발생된 일시지반변형과 매설된 상수도관 성능평가)

  • Jeon, Sang-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.4
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    • pp.2818-2827
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    • 2015
  • The spatial patterns and characteristics of these sequential earthquakes and ground motions induced by the earthquakes are examined by contours of peak ground velocity (PGV) and geometric mean peak ground velocity (GMPGV) using both ordinary kriging in geographical information system (GIS) and data, the records obtained from strong motion stations, acquired after recent sequential earthquakes in Canterbury, New Zealand (NZ). The performance of underground water pipeline system is examined by using data acquired after earthquakes. The spatial distribution of GMPGV is superimposed on water pipeline repairs throughout the water distribution system in areas affected principally by transient ground motion using GIS and then water pipeline repair rates, expressed as repairs/km, for different types of pipe are evaluated relative to the estimated GMPGV outside liquefaction areas. The earthquake performance of underground water pipeline systems is summarized in this study.

A Study on the Advanced Impedance Converter for Pipeline Health Monitoring (배관 안전진단을 위한 향상된 임피던스 컨버터 연구)

  • Kwon, Young-Min;Lee, Hyung-Su;Song, Byung-Hun
    • Journal of The Institute of Information and Telecommunication Facilities Engineering
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    • v.10 no.1
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    • pp.1-6
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    • 2011
  • The Underground pipeline facility is a general but most important facility in modern world, but its maintainability has been left behind. An automated and intelligent management technology is needed to prevent the wast of social resource and security. In this paper, we introduce Pipeline Health Monitoring(PHM) with Ubiquitous Sensor Network(USN) for inexpensive structure safety monitoring system, and improve its utility by inventing the advanced impedance converter.

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