• Title/Summary/Keyword: stiffening girder

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Buckling Stability in the deck Steel Girder of Cable stayed Bridge Considered Nonlinear Behavior of Stay Cable (케이블의 비선형 가동효과를 고려한 사장교 강거더의 좌굴 안전성 평가)

  • Choe Hak-Ze
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2005.04a
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    • pp.129-139
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    • 2005
  • The focused topic according to be slender and longer of cable stayed bridge's main span is as follows (1) Aerodynamic stability (2) Lateral movement of stiffening girder caused by wind force during and after construction (3) Global bucking of stiffening girder caused by axial force Among this, the number 3 has not received much attention in the past due to high buckling safety factor of stiffening girder. However, according to be slender of stiffening girder, the topic of buckling stability of girder is not any more unconcerned subject. The purpose of this paper is to examine the effect of stay cable's nonlinear behavior on the buckling stability of cable-stayed bridge.

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The Behavior Characteristic and Buckling Strength of Stiffening-Girder of Cable stayed bridge according to Pylon's shape and Flexure Stiffness (주탑형상 및 강성이 사장교의 거동 및 주형좌굴에 미치는 영향)

  • Choe Hak-Ze;Chae Gyu-Bong
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.759-763
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    • 2006
  • Cable Stayed Bridge is mainly composed of three element. Composed element are cable. stiffening girder and Pylon. The characteristic of bridge's behavior depend on these three element's relative stiffness, shape and system of bridge. The purpose of this paper is to exame the characteristic of bridge's behavior and buckling strength of stiffening girder according to shape and flexure stiffness of pylon

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A simplified analysis of the behavior of suspension bridges under live load

  • Stavridis, Leonidas T.
    • Structural Engineering and Mechanics
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    • v.30 no.5
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    • pp.559-576
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    • 2008
  • Having established the initial geometry and cable force of a typical three span suspension bridge under permanent load, the additional maximum response of the cable and the stiffening girder due to live load are determined, by means of an analytic procedure, considering the girder first hinged at its ends and then continuous through the main towers. The problem of interaction between the cable and the stiffening girder is examined taking under due consideration the second order effects, whereby, through the analogy to a fictitious tensioned beam under transverse load, a closed -form solution is achieved by means of a simple quadratic equation. It is found that the behavior of the whole system is governed by five simple dimensionless parameters which enable a quick determination of all the relevant design magnitudes of the bridge. Moreover, by introducing these parameters, a set of diagrams is presented, which enable the estimation of the influence of the geometric and loading data on the response and permit its immediate evaluation for preliminary design purposes.

Failure Analysis of Deteriorated Reinforced Concrete T-Girder Bridge Subject to Cyclic Loading (정적 반복하중을 받는 노후된 철근콘크리트 T형교의 파괴해석)

  • 송하원;송하원;변근주
    • Magazine of the Korea Concrete Institute
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    • v.10 no.6
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    • pp.291-301
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    • 1998
  • In this paper, two dimensional and three dimentional modeling techniques are proposed for the failure analysis of deteriorated reinforced concrete T-girder bridge subjected to cyclic loading up to failure. For the nonlinear failure anaysis, a tension stiffening model which can consider degradation of bond between reinforcement and surrounding concrete due to corrision of rebars in old bridge is proposed and a modeling technique for the supports conditions of the bridges which can consider degradation of bearing at supports in old bridge is also proposed, The analysis results along with comparisons with full-scale failure-test results confirm that finite element modeling techniques in this paper can be well applied to the failure analyses of in-situ old reinforced concrete T-girder bridges subjected to cyclic loading and the support condition modeling especially affects the bridge strength significantly.

Evaluation on the Edge Stiffening Affect of Composite Girder Bridge (합성형교의 외측강성 영향 평가)

  • Sung, Ki Tae;Park, Young Hoon;Lee, Seung Yong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.2A
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    • pp.179-186
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    • 2008
  • To analyzing the validity for using the stiffness ratio in evaluating edge stiffness effect of the composite girder bridges, modification factors are analyzed with changing girder spacing. The relation between stiffness ratio, loading type, girder spacing and modification factors is analyzed. From the results of comparing modification factors analyzed from the field loading test and the established design method with the modification factor analyzed from this study, it was concluded that evaluating the edge stiffness effect using stiffness ratio is possible.

A Structural Analysis Model for the Initial Configuration of a Suspension Bridge Considering the Erection Method of Stiffening Girders (보강형의 시공방법을 고려한 타정식 현수교의 초기형상해석 모델)

  • Ko, Seong Seok;Kang, Sung Hoo;Park, Sun Joon;Jung, Jae Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.4A
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    • pp.337-346
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    • 2009
  • To determine the initial configuration of the suspension bridge appropriate idealization model and analysis procedure are proposed as considering the boundary and loading conditions of stiffening girder during the erection. The construction stages of a suspension bridge are divided into two steps which are the first stage of the erection and the second stage of the completion in terms of the erection time of stiffening girders, and depending upon such an erection step the initial configuration analysis is classified the first configuration analysis and the revision analysis of the second configuration. The boundary and loading conditions and the analysis procedures for each stage are suggested and the results are verified by comparing with existing data. The results show that the proposed method provides better solution compared to the results using existing method.

A Study on Cable Anchor System in Cable-Stayed Railway Bridge (철도용 사장교의 케이블 정착구조에 관한 연구)

  • Kong, Byung-Seung
    • Proceedings of the KSR Conference
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    • 2005.11a
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    • pp.1229-1234
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    • 2005
  • Since the 20th century, the business of railway was invaded by the invention of airplanes and vehicles in the field of the transportation of passenger and commercial products, however, in the 21st century, the fervent development of a high speed railway made possible the huge capacity of transporting passengers and commercial freight, so the railway industry is facing a new era of railway revolution. The 200 years old railway tradition includes the history of railway bridges built in areas of river, valley and metropolitan region and in that, the number of constructions of railway bridges that is composed of cable-stayed bridges is increasing as one of the most optimal bridges considering the quality of materials and the span of continuous-welded long rail. Thanks to the minimized effects of the fixed load on the stiffening girder section by delivering the fixed load which is applied to the pylon with the composition of elastic supporting points by using cables and the effective structural system that can throughly resist extra loads in addition to fixed load, the long-extended span of a bridge becomes possible. In this structural system, the load that is applied to the stiffening girder section forms a now pattern and in the process of these load delivery, there will be a necessity to examine the concentration of stress occurred in the cable-anchor system of the cable.

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A Study on Stress Analysis of Cable Anchor System in Cable-Stayed Railway Bridge (철도용 사장교의 케이블 정착구조에 관한 형식별 FEM해석 연구)

  • Park, Ji-Ho;Kong, Byung-Seung
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.552-557
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    • 2006
  • Since the 20th century, the business of railway was invaded by the invention of airplanes and vehicles in the field of the transportation of passenger and commercial products, however, in the 21st century, the fervent development of a high-speed railway made possible the huge capacity of transporting passengers and commercial freight, so the railway industry is facing a new era of railway revolution. The 200 years old railway tradition includes the history of railway bridges built in areas of river, valley and metropolitan region and in that, the number of constructions of railway bridges that is composed of cable-stayed bridges is increasing as one of the most optimal bridges considering the quality of materials and the span of continuous-welded long rail. Thanks to the minimized effects of the fixed load on the stiffening girder section by delivering the fixed load which is applied to the pylon with the composition of elastic supporting-points by using cables and the effective structural system that can throughly resist extra loads in addition to fixed load, the long-extended span of a bridge becomes possible. In this structural system, the load that is applied to the stiffening girder section forms a flow pattern and in the process of these load delivery, there will be a necessity to examine the concentration of stress occurred in the cable-anchor system of the cable.

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An analytical algorithm for assessing dynamic characteristics of a triple-tower double-cable suspension bridge

  • Wen-ming Zhang;Yu-peng Chen;Shi-han Wang;Xiao-fan Lu
    • Structural Engineering and Mechanics
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    • v.90 no.4
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    • pp.325-343
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    • 2024
  • Triple-tower double-cable suspension bridges have increased confinement stiffness imposed by the main cable on the middle tower, which has bright application prospects. However, vertical bending and torsional vibrations of the double-cable and the girder are coupled in such bridges due to the hangers. In particular, the bending vibration of the towers in the longitudinal direction and torsional vibrations about the vertical axis influence the vertical bending and torsional vibrations of the stiffening girders, respectively. The conventional analytical algorithm for assessing the dynamic features of the suspension bridge is not directly applicable to this type of bridge. This study attempts to mitigate this problem by introducing an analytical algorithm for solving the triple-tower double-cable suspension bridge's natural frequencies and mode shapes. D'Alembert's principle is employed to construct the differential equations of the vertical bending and torsional vibrations of the stiffening girder continuum in each span. Vibrations of stiffening girders in each span are interrelated via the vibrations of the main cables and the bridge towers. On this basis, the natural frequencies and mode shapes are derived by separating variables. The proposed algorithm is then applied to an engineering example. The natural frequencies and mode shapes of vertical bending and torsional vibrations derived by the analytical algorithm agreed well with calculations via the finite element method. The fundamental frequency of vertical bending and first- and second-order torsion frequencies of double-cable suspension bridges are much higher than those of single-cable suspension bridges. The analytical algorithm has high computational efficiency and calculation accuracy, which can provide a reference for selecting appropriate structural parameters to meet the requirements of dynamics during the preliminary design.