• Title/Summary/Keyword: JCO

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Behavior Evaluation of Thin Bonded Continuously Reinforced Concrete Overlay on Aged Jointed Concrete Pavement(2) (노후 줄눈 콘크리트 포장 보수를 위한 얇은 연속 철근 콘크리트 덧씌우기 포장의 거동 평가(2))

  • Ryu, Sung-Woo;Cho, Yoon-Ho
    • International Journal of Highway Engineering
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    • v.12 no.4
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    • pp.101-110
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    • 2010

  • In this paper, it has been studied about the CRCO to maintain or rehabilitate the aged JCP. The CRCO and JCO was constructed at useless section of Seo-Hae-Ahn express highway in South Korea. The performance evaluation was conducted. Especially, it was focused on the roll of longitudinal reinforced steels inserted into the CRCO. On crack survey results from field construction section, the reflection cracks at joint of the existing pavement occurred in CRCO. However, due to the constraints of longitudinal reinforced steels, crack width was small. Total crack length and quantity in the CRCO more than that in the JCO. And crack spacing in the CRCO was narrower than it in the CRCP. Through the bonding strength test results, if the cold milling and cleaning as well as surface treatment is applied, there will be no debonding problem at interlayer in the early age. From analysis of the horizontal behavior at the joint, the longitudinal reinforced steels constrained crack width which became wider than initial state over time. Also, that steel in the CRCO reduced the horizontal movement due to temperature variation(4 times than that in the JCO). But, if interface is debonded, the roll decreased. Vertical VWG data showed that CRCO did not occur debonding problem at steel location, but there was some problem in JCO. It was confirmed by field coring. The tensile strain appeared in the CRCO, But the compressive strain occurred in the JCO in early age. Through the FWD test result, deflection in the CRCO was less than that in the JCO. And K value in the CRCO was greater than it in the JCO.

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Evaluation of HIC/SSCC Resistance for API-X70 Pipe Manufactured by JCO Bending Process and SA Welding (JCO 밴딩과 SA용접으로 제조된 API-X70급 강관의 HIC/SSCC 저항성 평가)

  • Ryoo, Hoi-Soo;Kim, Hee Jin;Lee, Dong-Eon
    • Journal of Welding and Joining
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    • v.32 no.5
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    • pp.1-6
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    • 2014

  • This study aims at manufacturing SA welded API-X70 line-pipe with sour gas resistance. A pipe was manufactured by JCO bending process and SA welding using the API-X70 plate guaranteed HIC resistance. SA welded pipe was expanded in order to reduce the residual stress. The evaluation of a pipe for resistance to HIC and SSCC were performed by the RS D 0004 and RS D 0005 standards. For verification that a pipe has acceptable resistance to HIC, fullscale test was carried out. Results showed no cracking for the HIC and SSCC.

  • https://doi.org/10.5781/JWJ.2014.32.5.1 인용 PDF KSCI

원자력발전소에서 작업자 인터페이스의 주기적 안전성 검증 방안

  • 민유종;장통일;김수진;이용희
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • 2003.10a
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    • pp.403-408
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    • 2003

  • 현대의 산업은 대규모 공정제어 시스템을 통한 작업자와 작업자 인터페이스의 상호 유기적인 관계를 통하여 운영되고 있다. 이러한 유기적인 관계가 고신뢰도 체계를 운영하고 있는 석유화학, 군사, 통신 등의 안전성 문제에 많은 영향을 미치고 있다. 실제 대부분의 안전사고가 시스템 자체에 문제보다는 시스템을 운영하는 인간-기계 연계 체제(Human-Machine Interface; HMI)에서 비롯된 것이다. TMI, 체르노빌, JCO 등의 사고를 통하여 원자력발전소(이하, 원전)에서는 작업자 인터페이스의 품질 문제가 강조되고 있다. 이러한 노력의 일환으로 우리나라도 원전에 대한 10년 주기의 주기적안전성평가(Periodic Safety Review: PSR)에서 인적요소 평가를 포함하고 있다.(중략)

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