• Wind and Structures
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• 제12권3호
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• pp.205-217
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• 2009

Aerodynamic flutter control for long-span cable-supported bridges was investigated based on three basic girder sections, i.e. streamlined box girder section, box girder section with cantilevered slabs and two-isolated-girder section. Totally four kinds of aerodynamic flutter control measures (adding fairings, central-slotting, adding central stabilizers and adjusting the position of inspection rail) were included in this research. Their flutter control effects on different basic girder sections were evaluated by sectional model or aeroelastic model wind tunnel tests. It is found that all basic girder sections can get aerodynamically more stabled with appropriate aerodynamic flutter control measures, while the control effects are influenced by the details of control measures and girder section configurations. The control effects of the combinations of these four kinds of aerodynamic flutter control measures, such as central-slotting plus central-stabilizer, were also investigated through sectional model wind tunnel tests, summarized and compared to the flutter control effect of single measure respectively.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1439-1449
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• 2007

The challenging aspect of CWR (continuous welded rail) is the additional axial forces in rails, mainly due to the thermal expansion of steel plate girder and rail itself. It has been found that these axial forces are proportional to girder length, total bridge length and bolt tightening forces. Also these forces are dependent to girder support conditions, types of bearings and their arrangements. With CWR, the authors' previous studies show that performance improvements like noise reduce, fatigue resistances and bearing durability increment can be expected. In addition to these effects, secondary effects due to the semi integral behavior between rail and bridge girder also can be expected. Special bearings which can reduce the absolute maximum axial forces have been developed, and applied to real 100m span bridge. The performance improvements were verified through site measurements and numerical analysis. The purpose of this study is to confirm the expected performance improvement aspects of steel plate girder bridges with CWR. To verify these aspects, girder stiffness changes, rail axial force changes, girder displacements and noise level were thoroughly measured and compared.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
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• pp.455-458
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• 2005

The Steel-Confined Prestressed Concrete Girder(SCP Girder) has been developed, which maximizes structural advantages of components (concrete, steel plate and tendon) and can be used to construct the middle or long span bridge with low-height girder. And recently, a continuous beam type of SCP Girder has been being developed to decrease size and self weight of girder in comparison with a simply-supported type. In this study, as part of developing the continuous beam type of SCP Girder, a new type of anchorage zone is proposed in order to address tendons effectively and decrease section size of SCP Girder efficiently. And also, the experimental test was carried out using a real scale specimen to examine the behavior of proposed anchorage zone.

• 한국전산구조공학회논문집
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• 제15권3호
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• pp.501-510
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• 2002

상자형의 중간격벽은 상자형의 단면변형을 구속하고 상부플랜지에서 발생되는 하중을 양측의 웨브에 분포시키는 역할을 한다. 그러나 상자형의 내부공간이 중간격벽으로 차단될 경우 내부공간을 활용할 수 없으며 유지관리에 많은 어려움을 격게 된다. 상자형의 격벽이 개구부를 갖는 경우 개구부가 없는 경우에 비하여 어떠한 영향을 갖는지를 실험을 통하여 중간격벽의 강성으로 표현하고자 하였다

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.240-245
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• 2005

There has been a strong demand on more economic and lower depth girder bridges for short and medium span range, PRECOM, which is a new type steel-concrete composite girder, has been developed to realize a more economic bridge system with a lower depth girder. In the PRECOM girder bridge, a steel plate girder is simply supported and then concrete form is hung to girder. Thus, the self-weight of the concrete is loaded to the steel girder. To increase the resistance of concrete in the lower casing against tensile stress, compressive force is introduced by prestressed tendon To evaluate the manufacturability and performances of the completed bridge, four 15-m girders and a bridge specimen with two 20m girders wvere constructed. The camber during the construction and introduction of an appropriate compressive force was evaluated. Dynamic data were obtained through the modal testing of the completed girders. Static loading test was also conducted to examine cracks and evaluate the decrease in stiffness and failure behavior under extreme conditions.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.417-420
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• 2004

The Prestressed concrete girder bridges(PSC girder bridges), consisting of prestressed concrete girders and cast-in-place deck slabs, are sensitive to creep and shrinkage of concrete. Shrinkage and creep produce additional internal forces md deformations in PSC girder bridges. The long-term behavior of the PSC girder bridges depends on time-dependent properties of materials, amount of prestressing, methods and sequences of construction and age at loading. The purpose of this study is to predict the long-term behavior of PSC girder bridge. For this purpose, Computer program for Time-dependent analysis of PSC girder bridge has been developed. thereafter, Time-dependent analysis using developed computer program was carried out about 3-span continuous PSC girder bridges. Various construction timing sequences were used for parametric study.

• 한국건설순환자원학회논문집
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• 제5권3호
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• pp.290-297
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• 2017

압축강도 160MPa와 길이 15.4m를 가진 분절형 U거더와 합성 U거더의 휨거동 실험을 수행하였다. 실험 변수로는 강섬유 혼입률과 U거더 상부의 슬래브이다. U거더의 복부와 하부플랜지에 종방향 철근을 배근하였다. 상부플랜지에 2개의 15.2mm 강연선을 포함한 2개의 프리스트레싱 텐던 그리고 하부플랜지에 7개의 15.2mm 강연선을 포함한 2개의 프리스트레싱 텐던이 배치되고 U거더 접합 시 한차례 긴장 작업을 하였다. 초고강도 콘크리트 강도로 인해 U거더에 도입한 충분히 강한 프리스트레싱 긴장력은 U거더 시공단계에서 자중과 고정하중을 부담할 수 있다. U거더의 취성적 거동에 비해 합성 U거더는 안정적이고 연성적인 하중처짐 관계를 보여주고 있다. U거더 상부에 슬래브를 시공한 후, U거더 접합 시 도입했던 프리스트레싱 긴장력에 의한 합성 U거더의 휨하중 내하력은 마지막 하중 단계에서 설계하중을 부담할 수 있다. 초고강도 콘크리트로 인한 간단한 프리스트레싱 방법은 시공단계와 공사비 면에서 장점을 가지고 있다. 간격이 작은 전단키는 초고강도 콘크리트 U거더와 고강도 콘크리트슬래브간의 완전한 합성관계를 가져와 파괴하중 직전까지 슬립현상이나, 벌어짐 현상을 보이지 않았다.

• 한국안전학회지
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• 제31권6호
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• pp.45-51
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• 2016

The purpose of this study is to investigate the influence of train-induced end rotation of simple supported track girder on the performance of a direct fixation track system (DFTS) in Yeongjong grand bridge. In this study, the influences of deflection of a DFTS and track girder on dynamic rail-track girder interaction forces for the track girder ends currently employed in airport express lines were assessed by performing field tests using actual vehicles running along the service lines. Therefore, the dynamic displacement of rail and track girder and the fastener stress on the center and ends sections of DFTS were measured for two different trains (AREX and KTX) running in Yeongjong grand bridge. A three-dimensional finite element analysis (FEA) model using the time-history function based on the design wheel load was used to predict the train-induced track and track girder displacement, and the FEA and field test results were compared. The analytical results reproduced the experimental results well within about 3-7% difference in the values. Therefore, the FEA model of DFTS on track girder is considered to provide sufficiently reliable FEA results in the investigation of the behavior of DFTS. Using the analytical and experimental results, the influence of train-induced end rotation of simple supported track girder on the interaction behavior of rail and track girder installed on a simple supported track girder ends, i.e., upward displacement of rail-track girder and the fastener stress, was investigated. It was found that the train-induced end rotation effect of track girder was not significantly affected by the upward displacement of rails and the fastener stresses of track girder ends. Further, the interaction behavior of rail and track girder were similar to or less than that of the general railway bridge deck ends, nevertheless the vertical displacement of track was higher than that of conventional DFTS on the general railway bridge. From the results, the dynamic responses of the DFTS on track girder ends were not significantly affected by the safety and stability of DFTS ends.

• 콘크리트학회논문집
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• 제27권4호
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• pp.377-385
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• 2015

PSC I 거더의 장경간화는 단면의 세장비와 자중의 영향 등을 증가시켜 거더의 횡적 불안정에 대한 위험성을 높였다. 특히 최근에는 시공 중 거더의 전도 붕괴사고가 증가하고 있어 거더의 횡적 불안정성에 대한 평가 기술이 절실히 요구되고 있다. 따라서, 본 연구에서는 시공 중 전도 붕괴의 한 원인으로 판단되어지고 있는 풍하중에 대하여 PSC I 거더의 횡방향 거동 특성과 안정성을 평가하였다. 거더의 횡방향 불안정성은 주로 거더의 길이와 받침의 강성 변화에 의해 영향을 받는다. 해석결과에 의하면 거더의 경간장이 증가함에 따라 거더의 횡적 불안정성을 유발할 수 있는 임계 풍하중은 감소하고, 거더의 변형과 회전각, 받침의 회전각은 모두 증가하였다. 최종적으로 시공 시 PSC I 거더의 임계 풍하중과 임계 횡변위량을 계산할 수 있는 해석식을 제시함으로써, 시공 시 거더의 횡적 안정성을 유지하기 위한 정량적 관리 수치를 제공할 수 있으리라 판단된다.

• 한국구조물진단유지관리공학회 논문집
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• 제9권3호
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• pp.151-160
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• 2005

현재의 교량설계기준에서는 연속거더교량에 대한 활하중 분배계수 규정에 대해 명확한 언급이 되어있지 않다. 따라서 이 논문의 목적은 단순교에 사용되는 시방서 규정 활하중 분배계수가 연속거더교에도 적용이 가능한지를 유한요소해석에 의해 검증하는 것이다. 연속거더교에 대한 활하중 분배의 영향을 검증하기 위해 5개의 공용중인 연속교에 대한 유한요소해석을 실행하였으며 그 결과 연속교에서 정모멘트 구역과 부모멘트 구역에서 활하중의 분배 형태는 매우 비슷하다는 결론을 내릴 수 있었다. 또한 처짐값의 비교에서 얻어진 활하중의 분배와 변형율에 기본한 활하중의 분배 양상의 차이가 거의 없는 것으로 나타났다. 해석 결과 현재 사용되고 있는 설계기준의 활하중 분배에 대한 규정은 연속거더교에 대해 매우 보수적이라고 판단된다.