• Journal of Korean Society of Disaster and Security
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• v.12 no.3
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• pp.35-49
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• 2019

Currently in 2018, Korea has over 600 operating sewage disposal facilities. The law requires a sewage treatment plant to treat 500 tons or more of water per day, and a small-decentralized sewage treatment facility in a community to treat 50 tons or more to less than 500 tons of water per day. However, most facilities fulfill neither the quantity nor the quality requirements from the original design for such reasons as inflow of rainwater and ground water due to deterioration of pipelines and unauthorized input of wastewater in the pipelines. The research has selected 2 representative cases among the technical diagnosif sewage pipelines in many regions within the country to use it as the baseline of: hourly flowrate and BOD water quality analysis in both clear and rainy days, proper plant operation through inflow rate and ratio calculation, and diagnostic evaluation for deterioration of the pipelines and their accessary structures. This also suggests facilities that treats 500 tons or more of inflow per day to sample and analyze the water hourly for 24 hours once a week in both clear weather and rainy weather considering the influence of rainfall on a regular basis.

• Journal of the Korean Institute of Gas
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• v.5 no.2 s.14
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• pp.30-35
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• 2001

Presently, working gas pipelines are being subjected to the influence of construction vibration. Especially on subway and road construction, gas pipelines are being influenced to construction vibration caused by use of construction equipment, passage of a large-sized vehicle and blasting. Buried gas pipelines are subjected to the influence of vibration caused by blast in the vicinity of pipeline, exposed gas pipelines are subjected to the influence of vehicle vibration. Therefore, in the study, it is developed to vibration prediction program of gas pipeline by analyzing measured construction vibration. This program is able to predict vibration of gas pipeline according to field conditions by using the results of structural finite element analysis and empirical equation by reliability analysis. And, this program contains the database of construction vibration. Additionally, this program is able to compute estimated blast vibration equation using measured blast vibration data in the field and to form graph of allowable charging gunpowder per delayed-action with the change of blast velocity. Therefore, field workers are able to predict construction vibration around gas pipeline and estimate safety of gas pipeline.

• Journal of the Korean GEO-environmental Society
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• v.16 no.9
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• pp.43-51
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• 2015

In this paper, a 3D shell-spring model that can perform time history analysis of buried pipelines is used to evaluate the effect of the incident direction of the earthquake motion. When applying harmonic motions, it is shown that the period of vibration has pronounced influence on the response of buried pipelines. With decrease in the period, the curvature of the pipeline and corresponding response are shown to increase. To evaluate the effect of the incident angle, the motions are applied in the direction of the pipleline, horizontal, and vertical planes. When the motion is applied parallel to the direction of the pipeline, it only induces bending strains and therefore, the response is the lowest. Under motions subjected in horizontal and vertical planes at an angle of $45^{\circ}$ from the longitudinal axis of the buried pipeline, the axial deformation is shown to contribute greatly to the response of the pipelines. When imposing two-components simultaneously, the calculated response is similar to the case where only single-component is imposed. It is because one component only induces bending strain, resulting in very small increase in the response. The trend of the response is shown to be quite similar for recorded motions. Therefore, it is concluded that use of a single-component is sufficient for estimation of the longitudinal response of buried pipelines.

• Journal of the Korean Institute of Gas
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• v.20 no.4
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• pp.33-43
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• 2016

Grinding, weld deposition, type A sleeve, type B sleeve, composite sleeve, hot tapping and clamp are used as the method to repair the buried pipelines in the United States, UK and Europe. In the event of defect to the pipeline, they have repaired the pipeline through the fitness-for-service assessments. In addition, they have guidelines for the possible repair methods to apply to each type of damage, which is occurred due to the 3rd party construction or corrosion. According to the KGS FS551, Safety Validation in Detail including ECDA(External Corrosion Direct Assessment) as one method of integrity management should be carried out for the old pipeline which supply natural gas as the middle pressure in Korea. Where a defect on the pipelines is found, on the result of Safety Validation in Detail, the pipelines should be repaired or replaced by new piping. However, there are no guidelines or regulations regarding the repair and reinforcement of pipeline, so that, cutting the damaged pipeline and replacing it as a segment of new pipe is the only way in Korea until now. We have suggested pipeline repair methods including type A, B sleeve, composite sleeve, after the survey of foreign repair method and standards including the method of United States and the United Kingdom, and after analysis of the results on pipeline repair test including type A, type B sleeve and composite sleeve.

• Journal of the Korean GEO-environmental Society
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• v.23 no.4
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• pp.5-10
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• 2022

Recently, ground subsidence has been continuously occurring in downtown areas, threatening the safety of citizens. Various underground facilities such as water and sewage pipelines and communication pipelines are buried under the road. It is reported that the cause of ground subsidence is the deterioration of various facilities and the reckless development of the underground. In particular, it is known that the biggest cause of ground subsidence is the aging of sewage pipelines. As an existing study related to this, several representative factors of sewage pipelines were selected and a study to predict the risk of ground subsidence through statistical analysis has been conducted. In this study, a data SET was constructed using the characteristics of OO city's sewage pipe characteristics and ground subsidence data, The data set constructed from the characteristics of the sewage pipe of OO city and the location of the ground subsidence was used. The goal of this study was to present a classification model for the occurrence of ground subsidence according to the characteristics of sewage pipes through machine learning. In addition, the importance of each sewage pipe characteristic affecting the ground subsidence was calculated.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.288-289
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• 2005

• 한국가스학회:학술대회논문집
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• 1998.09a
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• pp.203-208
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• 1998

• 한국가스학회:학술대회논문집
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• 2001.10a
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• pp.98-102
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• 2001

• 한국가스학회:학술대회논문집
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• 2001.10a
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• pp.103-107
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• 2001

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.904-905
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• 2005