• Wind and Structures
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• 제38권5호
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• pp.399-410
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• 2024

Long-span suspension bridges located in typhoon-prone regions face significant risks of flutter instability, particularly in girder erection. Despite the implementation of aerodynamic countermeasures designed for the service stage, the flutter stability of bridge in girder erection may not meet the required standards. Nowadays, the double-deck truss girder is increasingly common in practical engineering which exhibits different performance from the single-deck truss girder. To gain insights into the flutter performance of this girder type and determine temporary aerodynamic countermeasures for flutter suppression in girder erection, wind tunnel tests were conducted. The effects of affiliated members on the flutter performance were first examined. Subsequently, different aerodynamic countermeasures were designed and their effectiveness was tested. The results indicate that the stabilizers above and below the upper and lower decks are the most effective for the flutter stability of bridge at positive and negative angles of attack, respectively. The higher the stabilizers are, the better the effect on flutter suppression achieves. Considering the feasibility in practical engineering, a temporary stabilizer above the upper deck was considered. It is expected that the results could provide references for the aerodynamic design of double-deck truss girder during erection.

• 대한토목학회논문집
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• 제29권4A호
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• pp.337-346
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• 2009

타정식 현수교의 보강형 가설중의 경계조건과 하중조건의 변화를 고려하여 초기형상을 결정하기 위한 구조해석 모델링 방법 및 해석 알고리즘을 제안하였다. 타정식 현수교의 가설단계를 보강형의 가설시점을 기준으로 보강형 가설단계인 1단계와 완공단계의 2단계로 구분하였으며 이러한 가설단계를 고려하여 초기형상해석 단계를 1차 형상해석과 2차 형상보정해석의 2단계로 구분하였다. 각 해석단계에 대한 보강형의 경계조건과 작용하중의 모델링 방법 및 반복해석 알고리즘을 제안하였으며 실 교량에 대해 수치해석을 수행하여 기존 해석방법에 의한 초기형상해석결과와 비교, 분석하였다. 실 교량에 대한 수치해석 결과 기존 초기형상해석방법의 문제점을 파악할 수 있었으며 본 연구에서 제안된 방법을 적용할 경우 기존 방법의 문제점을 해결할 수 있음을 확인하였다.

• 콘크리트학회지
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• 제22권2호
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• pp.55-59
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• 2010

• 전산구조공학
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• 제31권2호
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• pp.22-33
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• 2018

• 콘크리트학회지
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• 제19권3호
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• pp.38-43
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• 2007

• Wind and Structures
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• 제37권1호
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• pp.39-56
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• 2023

To ensure the wind stability of a long-span suspension bridge during deck erection under skew wind, based on the aerostatic and self-excited aerodynamic force models under skew wind, a computational approach of refined flutter analysis for long-span bridges under skew wind is firstly established, in which the effects of structural nonlinearity, the static wind action and full-mode coupling etc are fully considered, and the corresponding computational procedure is programmed. By taking the Runyang suspension bridge over the Yangtze River as example, the flutter stability of the bridge in completion under skew wind is then analyzed with the aerodynamic parameters of a similar bridge deck measured from the sectional model wind tunnel test under skew wind. Finally, through simulating the girder segments erected symmetrically from the midspan to towers, from the towers to midspan and simultaneously from the towers and midspan to the quarter points, respectively, the evolutions of flutter stability limits during the deck erection under skew wind are investigated numerically, the favorable aerodynamically deck erection sequence is proposed, and the influences of skew wind and static wind effect on the flutter stability of suspension bridge under construction are ascertained.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 가을 학술발표회 논문집
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• pp.368-373
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• 1994

Recently, a large number of box girder bridges with cantilevered decks have been constructed. Especially, segmentally erected prestressed concrete box girder bridges are widely used as economic and aesthetic solutions for long span bridges. Segmental erection is a particularly attractive construction alternative in cases where continuously supported formwork is impractical or uneconomical. In segmentally erected bridges, the structural systems are changed as the construction stages are progressive and redistribution of member forces occurs due to time dependent effects of concrete and relaxation of prestressing steel. Then, in segmentally erected bridges, analysis are required at each construction states. In this study, nonlinear analysis progam of the segmentally erected prestressed concrete box girder bridges is developed in taking into account nonlinearity of material and geometry, time dependent effect of concrete and relaxation of prestressing steel.

• 콘크리트학회지
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• 제22권1호
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• pp.59-64
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• 2010

• 콘크리트학회지
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• 제19권3호
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• pp.31-37
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• 2007

• Structural Engineering and Mechanics
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• 제35권5호
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• pp.539-554
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• 2010

Light weight superstructure is beneficial for bridges in remote areas and in emergency erection. In such weight sensitive applications, combination of fibre reinforced plastics (FRP) as material and box-girders as a structural system have great scope. This combination offers various options to tailor structure and its elements but this flexibility poses greater challenge in optimum design. In this paper a procedure is derived for a generalised optimum design of FRP box-girder bridges, using genetic algorithms (GA). The formulation of the optimum design problem in the form of objective function and constraints is presented. Size, configuration and topology optimization are done simultaneously. A few optimum design studies are carried out to check the performance of the developed procedure and to get trends in the optimum design which will be helpful to the new designers.