• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.104-107
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• 2008

A case study is conducted by between using 3D integrated automatic design software(ABeamDeck, AAbutPier) and using autocad without program to validate the method. As a result, there are many profits introducing the 3D design in the construction, especially, to make up for defect of existing design method. 3D design will enhance the efficiency of construction tasks by supporting a system of sharing and exchanging information throughout all the stages of construction, from design, production and installation to maintenance.

• Magazine of the Korea Concrete Institute
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• v.14 no.5
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• pp.59-68
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• 2002

서해대교, 영종대교 및 영흥대교 등 일련의 케이블을 이용한 장대교량의 성공적인 건설은 우리나라의 교량설계 및 시공기술에 있어 새로운 전환점을 맞이하는 계기가 되었다. 이러한 추이에 맞추어 최근의 교량설계는 사하중의 경감, 형(거더)의 경량화, 시공성, 경제성 및 유지관리 향상을 도모하며, 특히 지역적 특성에 맞는 이미지를 부각한 랜더마크(landmark)의 기능 및 주변환경과의 조화면에 많은 주안점을 부여한다. 그러나 교량형식 선정시 경험에 의해 기입증된 안정성 및 경제성을 확보한 형식으로 설계자의 사고가 제약되기 때문에 신기술, 새로운 형식의 교량이 우리나라에 도입되기 어려운 실정이다.(중략)

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.985-990
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• 2001

The widened Seoul-Bridge is the first continuous 8-span prestressed concrete(PSC) girder bridge in domain. The construction sequence of the bridge consists of S steps in a large way. The measuring in construction stage includes the determination of the allowable fluctuation value of beam stress in each step and the measurement beam stress during prestessing. The measured tendon prestress force was compared with the design value. When it was compared with the analytic result, the difference between the measured stress and the analytic stress was below allowable error. The friction loss and the anchorage slip loss of the tendon prestress force was lower than the design loss value.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.97-100
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• 2010

3차원 정보모델에 기반한 설계 자동화 프로그램의 개발은 좀 더 완성도가 높은 설계안을 도출할 수 있는 방안을 제시할 수 있다. 콘크리트 교량의 설계 과정에서 정형화된 구조 검토 단계 부분을 자동화하고 설계자로 하여금 좀 더 창의적인 설계가 가능하도록 지원하는 시스템을 개발하였다. 특히, 3차원 Building Information Modeling 기반의 프리스트레스트 콘크리트 박스 거더교에 대한 설계 자동화 시스템을 개발하였다. 이를 위하여 3차원 렌더링 알고리즘을 사용하여, 사용자가 원하는 단면 위치 및 분류 체계에 따라 설계를 자동으로 수행할 수 있도록 적용하였다. 또한 생성된 도면은 데이터 호환이 가능함으로써, 사용자의 편의성이 향상될 것으로 판단된다. 이는 설계자동화 분야에서 강교에 국한되었던 점을 콘크리트교를 포함한 주요 교량으로 확대하고 설계 성과품으로 3차원 모델을 도출할 뿐 아니라 2차원 도면을 연계하도록 구성하여 토목 엔지니어의 기술력을 향상시킬 것으로 기대된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2A
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• pp.65-73
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• 2012

In this study, we tested structural performance of Half-Decked PSC girder which was developed for applying to long span bridge. We operated 4 point bending test with 60 m span full scale girder designed as simple bridge with hinge-roller boundary condition. Actuators were set on the both sides of girder, 5.5 m away from the center, and 4 stages of cyclic loading was applied at rate of 1 kN/sec. Through stages 1 to 4, loading and unloading 1,000 kN, 1,200 kN, 1,500 kN, and 2,000 kN were repeated and displacement, strain of concrete and steel, crack of girder were checked. From these results, the strength of girder was assessed and resilience and ductility were observed after removing the load. Since initial flexural crack occurred in the vicinity of 1,400 kN, non-linearity of load-displacement curve appeared and definite residual strain was measured at that point. The test result showed that initial cracking load was over twice the DB-24 load which means the developed girder had sufficient strength. To verify the experimental results, we numerically analyze the test and confirmed that the data were similar with results from the test above. Half-Decked PSC type of 60 m-girder developed in this study showed its adequate structural capacity through static loading test, which proved that possibility of applying the girder to actual bridges practically.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.1741-1751
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• 2013

The main purpose of this study is to investigate the static behavior of a prestressed concrete (PSC) girder using pre-tension method. A 30m long full-scale pretension PSC girder is fabricated by the portable fabrication system and tested. All results have been compared to those obtained from F.E.A results. Deflections at the middle of girders have been measured for evaluation. Also, strains of concrete at the middle of span have been measured. From the results of experimental, the load when initial crack was developed was obtained to be 1.75 time the unfactered design load in the full-scale girder specimen. Also, the data of specimen are satisfied the desgin requirements of ductility on the Korea Bridge Design Specification(2010). In service state, the vertical deflection at center of test specimen when a initial crack was developed is satisfied the vertical deflection requirement under live load of the Korea Bridge Design Specification(2010). To verify the experimental results, we numerical analyze the test and confirmed that the data were similar with results from the test above. The pretension girder fabricated in site were found to have enough strength for safety under and after construction.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.297-300
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• 2008

Friction coefficients of the prestressing tendon are the basic information required to control the prestressing force introduced to PSC structure during jacking. However, the friction coefficients show considerable differences depending on the specifications, causing much confusion to designers. In this study, a procedure is proposed that can be used to estimate the wobble and curvature friction coefficients from field data and classical theory related to the friction. The procedure is applied to two PSC girder bridges with various tendon profiles. The resulting values are compared with those presented in some specifications and assumed in jacking. The resulting wobble friction coefficients are not as small as those presented in AASHTO specifications but are more or less similar to the lower limit of domestic standards, while the curvature friction coefficients approach or slightly exceed the upper limit of the same standards.

• Journal of the Korea Concrete Institute
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• v.19 no.4
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• pp.433-439
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• 2007

The main objective of the paper is to investigate the static behavior of a prestressed concrete (PSC) girder that has been spliced with precast box segments. A 20 m long full-scale spliced PSC girder is fabricated and tested to compare its static performance against a monolithic girder. The monolithic girder has the same geometric and material properties with respect to the spliced girder. This includes infernal strain, deflections, neutral axis position, and crack patterns for both girders. The test also consists of monitoring relative displacements occurring across the joints. Both the horizontal displacement (gap) and vertical displacement (sliding) are measured throughout the loading procedure. All results have been compared to those obtained from the monolithic girder. It has been demonstrated that the spliced girder offers close behavior with respect to the monolithic girder up to the crack load. Both girders exhibits ductile flexural failure rather than abrupt shear failure at joints.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.57-60
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• 2008

Maglev is a system that a train runs levitated above a rail. Therefore it is very important to maintain a constant levitation gap for achieving serviceability and ride comfort. This study is a cooperation research subject of the 3-1 subject, performance improvement of maglev track structures, of the Center for Urban Maglev Program in Korea, started in 2006. The aim of this study is development of rapid constructions of bridge superstructure for maglev. At present, precast deck is widely used because of its superiority to cast-in-place concrete on quality and the term of works. The research group suggested basic systems of maglev guideway with PSC-U type and trapezoidal open steel box type girder, and precast deck, cooperating with Korea Railroad Research Institute, the managing institute of the 3-1 subject. In this study, a mock-up consisted of girders, decks and rail was fabricated and test was performed for constructability, serviceability and maintenance evaluation of PSC U-type girder, precast deck, and new guide rail system.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.405-408
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• 2008

The most effective factors that improve sections and elongate spans of the prestressed concrete girders are shapes of sections and strengths of concretes, and the concrete strength is more influenced to enhance the allowable tensile strength on top and bottom fibers than increasing of flexural strength of girders. In this study, 60 MPa high-strength prestressed concretes were constructed at the Wonsoo Bridge where in the 1st section of expanding constructions of the Nonsan to Junjoo Expressway, the high-strength concrete was placed on the eight- 35 meters simple span IPC girders of four lanes of Nonsan direction. During casting of girder concretes, quality controls were carried out with continuing controls of surface moistures and corrections of the unit water using the air-meter methods right after batching. It was confirmed that compressive strengths of girder concretes ensure the target strength and the heat of hydrations of girder concrete were measured. Though using same materials and constructing methods, there're a wide range of strengths of each girder, so, when high-strength concretes cast in the place hereafter, a countermove should be prepared.