• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1998.05a
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• pp.83-88
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• 1998

가스배관은 주로 도로를 따라 매설되어 있으며, 최근 지하철공사가 도심지에서 도로를 따라 지속적으로 이루어지고 있으므로 지하철공사시 기존에 매설되어 있는 가스배관이 대기로 노출되고 있다. 노출된 배관의 자중을 지탱해 주기 위하여 전용보를 설치한 후 와이어로프를 이용하여 가스배관을 전용보에 매달아 놓은 상태에서 지하구조물 공사를 하고 있으며, 도로는 임시적으로 철판으로 복공하여 사용하고 있는 실정이다. (중략)

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.643-644
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• 2006

자기누설탐상시스템은 지하에 매설된 가스관에서 발생되는 부식이나 크랙 또는 기계적 변형을 탐지하기 위한 방법으로 비파괴검사 방법의 하나이다. 가스관은 Nd자석에 의해 착자가 되고, 가스관에 부식이 발생했을 경우 가스관의 단면적이 작아지게 되어 자기누설이 발생하며, 발생된 자기누설을 홀센서로 검출하여 부식의 유무, 크기, 모양 등을 판별하게 된다. 지하매설 배관은 배관의 직경은 같으나 배관의 두께는 다양하게 존재한다. 특히 30inch의 배관에는 배관의 두께가 11.1, 14.3, 17.5 mm 등이 있다. 자기누설탐상시스템은 배관의 단면적 변화를 감지하는 것이기 때문에 배관의 두께에 따라 그 특성이 변화하게 된다. 또한 두께에 따른 결함의 종류에 따라서 검출신호도 변화하게 된다. 따라서 본 논문에서는 배관의 두께 변화에 따른 검출신호를 분석하였으며, 두께 변화의 영향을 적용하여 검출신호를 보정하기 위한 방법을 제시하였다.

• Journal of the Korean Institute of Gas
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• v.4 no.2 s.10
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• pp.37-45
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• 2000

The underground buried pipelines of Natural gas are relatively safer than any other pipelines of chemical plants, because Natural gas is non-corrosive fluid. But Natural gas is supplied normally the downtown area. So, it may be a disaster because of corrosion which is caused interference facilities, environment and third party accident which is caused facilities construction. Especially, it is very difficult to find out and inspect damages of pipeline because of buried pipelines. Therefore this paper approached to select and manage risk region pipelines according to introduction of underground buried pipeline's risk concept. Risk was indicated three parts - corrosion factor, design and construction factor, maintence and management factor - in this paper, Therefore qualitive risk of pipelines showed score as quantitative number. Also it was thought to be helpful in confidence and safety management that the concept of key index and failure supplementation measures to cost introduces this program. We developed this risk assessment program using visual basic tool and interfaced GIS.

• Journal of the Korean Institute of Gas
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• v.13 no.2
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• pp.7-13
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• 2009

In order to make the critical path analysis of gas pipeline located under rigid pipes for interference behavior, FE analysis is performed considering real buried conditions of a drain and a gas pipe according to intersection angle of two pipes. A drain pipe and gas pipe have cover depth respectively 1.0m and 3.39m and this study considers a interference angle in the range of $0{\sim}90^{\circ}$. In this paper, the critical path is analyzed from the result of Ring Deflection and bending stress according to intersection angle. In the event intersection angle of two pipes equal to the critical path of lower pipe. The analysis results show that the critical path of lower gas pipe according to interference behavior has relation to intersection angle of two pipes.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2015.11a
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• pp.224-226
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• 2015

지하 매설 배관의 장기적 사용은 배관의 안전성과 건전성이 확보되어야 한다. 이를 위하여 진단, 평가, 보수에 대한 기술을 확보하고 지속적인 모니터링이 필요한 상태이다. 본 연구는 이러한 배관에 대한 건전성 평가를 활용하여 보수우선순위에 따라 배관을 관리할 수 있게 하는 기술을 개발하는 것이다. 이를 위하여 평가를 할 수 있는 모델에 대한 연구 그리고 모델을 실제 도시가스회사의 시스템과 연계하기 위한 기술 개발에 대한 연구가 진행되었다.

• Journal of the Korean Institute of Gas
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• v.23 no.2
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• pp.28-34
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• 2019

A large number of underground pipelines in the Ulsan National Industrial Complex has been constructed to improve the productivity of chemical products and tackle transportation problems. Now, the total of 1,293km of underground pipelines around 62 companies has been installed and operated. Many of underground pipelines have been installed outside of factories. For a past three years, five gas leakage accidents have occurred and the emergency response took up to 8 hours or more. Due to these delay in accidents, second serious accidents might occur and lead to occur damages to adjacent residents. In this study, it is assumed that emergency valve systems are installed under a ground and the efficacy of these is verified. Consequence analysis program was employed to evaluate the mitigation impact of emergency valve systems. The results show that these valve systems are economical and their performances for a mitigation are excellent. The results indicate that the installation of emergency valve systems for underground pipelines should be urgently legislated and performed.

• Journal of the Korean Institute of Gas
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• v.27 no.4
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• pp.19-26
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• 2023

Earthquakes are one of the most important disasters affecting underground structures. Urban gas underground pipes may cause safety problems of structures in the event of an earthquake. Since Korea began digital observation, the number of earthquakes has been steadily increasing. The seismic design standard for urban gas pipes was established in 2008, but it is difficult to estimate the impact of pipes in the event of an earthquake based on the installation of pipes. In this study, structural analysis was performed on PE (polyethylene pipe) pipes and PLP (polyethylene coated steel pipe) pipes, which are mainly used as buried pipes in Korea, according to environmental and pipe variables in the event of an earthquake. This study sought to find the variables of the most vulnerable buried pipe by modeling pipes through Computer Aided Engineering (CAE) and generating displacement on the ground. Through this study, it was confirmed that the larger the elastic modulus of the soil, the deeper the buried depth, the smaller the tube diameter, and the higher the pressure, the more PLP pipes are affected by earthquakes than PE. Based on these results, the vulnerable points of buried urban gas pipes are inferred and used for special inspections of buried pipes in the event of an earthquake.

• Journal of the Korean Institute of Gas
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• v.15 no.2
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• pp.27-32
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• 2011

In this paper a new defect length estimation algorithm using SQI(self quotient image) is presented for the MFL(magnetic flux leakage) inspection of underground gas pipelines. Gas pipelines are magnetized by the permanent magnets of the MFL PIG(pipeline inspection gauge) when the PIG runs through pipelines. If defects or corrosions exist in the pipeline, magnetic leakage flux is increased. The MFL signals measured by hall sensors are analyzed to estimate defect length using SQI. For 74 real defects carved in KOGAS pipeline simulation facility(KPSF) the accuracy of defect length estimation of the proposed algorithm was compared with that of conventional methods.

• Journal of the Korean Institute of Gas
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• v.13 no.2
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• pp.30-35
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• 2009

The result of this research explains an interactive behavior of buried steel pipe located below hume pipe using concept of effective depth and effective length against their intersection angle and burial distance. The cover depth of upper rigid (hume) pipe is 1.0m and depth range of flexible (steel) pipe is 0.5m to 5m from beneath bottom of hume pipe. And one more variable is their intersection angle in this study, it was considered from $0^{\circ}$ to $90^{\circ}$. From the results of this study, the effective depth is proportionally increasing with its intersection angle and decreasing with distance increment between two pipes. Finally, the relationship between effective length and summation of occurred bending stress is defined.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.06a
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• pp.7-12
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• 2000

전국에 천연가스를 공급하기 위해 지하에 매설된 가스배관은 파괴 또는 파손 발생시 경제적, 인적인 면에서 대형 재해를 일으킬 뿐만 아니라 에너지의 안정한 공급이 위협받게 되어 산업적인 면에서도 큰 손실을 유발하게 된다. 가스배관에 대하여 적합한 파괴안전성 평가를 수행하고, 불가피한 손상이 발생할 경우 사용적합성평가(Fitness For Service)를 통해 대처방안을 수립할 경우, 에너지 공급의 안정화 및 경제적, 사회적 손실의 방지를 이루며 안전하고 효율적인 배관망 운용을 할 수 있다. (중략)