• Title/Summary/Keyword: Pipe-Joining

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A Study on the Improvement of Construction Cost Standards for Pipe Laying and Joining Work (관 부설 및 접합공사 공사비산정기준 개선에 관한 연구)

  • Oh, Jae-Hoon;Ahn, Bang-Ryul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.7
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    • pp.675-684
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    • 2020

  • To prevent safety accidents caused by aging pipe infrastructure and to maintain water quality, construction projects for water and sewage pipes are actively conducted across Korea. This study analyzed the criteria situations, site survey details, and regulation revisions related to the calculation of construction cost standards for pipe laying and joining work. The analysis showed that the major causes for revision are the unclear construction scope, limitations in implementing some pipe materials due to installation facility types, workforce focused on ordinary labor, limitations of manual laying work, and the lack of tool hire cost and machine expense-calculation criteria. Field studies were conducted to categorize the pipes according to their features, in addition to identifying the use of lifting heavy equipment and light equipment. In addition, excavation and testing work conducted in connection to pipe laying, as well as the use of skilled labor, were investigated. The current study clarified the work scope through new common items, provides an organization based on the pipe material, adjusted the workforce ratio to focus more on skilled labor, and developed grounds for calculating machine expenses. These revisions were estimated to save approximately 1.28% of the construction costs in each project according to an analysis of the construction cost impact study. truction costs in each project, according to an analysis of construction cost impact study.

  • https://doi.org/10.5762/KAIS.2020.21.7.675 인용 PDF KSCI

A Study on Seam Tracking and Weld Defects Detecting for Automated Pipe Welding by Using Double Vision Sensors (파이프 용접에서 다중 시각센서를 이용한 용접선 추적 및 용접결함 측정에 관한 연구)

  • 송형진;이승기;강윤희;나석주
    • Journal of Welding and Joining
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    • v.21 no.1
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    • pp.60-65
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    • 2003

  • At present. welding of most pipes with large diameter is carried out by the manual process. Automation of the welding process is necessary f3r the sake of consistent weld quality and improvement in productivity. In this study, two vision sensors, based on the optical triangulation, were used to obtain the information for seam tracking and detecting the weld defects. Through utilization of the vision sensors, noises were removed, images and 3D information obtained and positions of the feature points detected. The aforementioned process provided the seam and leg position data, calculated the magnitude of the gap, fillet area and leg length and judged the weld defects by ISO 5817. Noises in the images were removed by using the gradient values of the laser stripe's coordinates and various feature points were detected by using an algorithm based on the iterative polygon approximation method. Since the process time is very important, all the aforementioned processes should be conducted during welding.

  • PDF KSCI