• Title/Summary/Keyword: 교량 설계

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Analysis and Prediction for Abutment Behavior of Prestressed Concrete Girder Integral Abutment Bridges (프리스트레스트 콘크리트 거더 일체식 교량의 교대 거동 해석과 예측)

  • Kim, Woo-Seok
    • Journal of the Korea Concrete Institute
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    • v.23 no.5
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    • pp.667-674
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    • 2011
  • This paper discusses the analysis method of prestressed concrete girder integral abutment bridges for a 75-year bridge life and the development of prediction models for abutment displacements under thermal loading due to annual temperature fluctuation and time-dependent loading. The developed nonlinear numerical modeling methodologies considered soil-structure interaction between supporting piles and surrounding soils and between abutment and backfills. Material nonlinearity was also considered to simulate differential rotation in construction joints between abutment and backwall. Based on the numerical modeling methodologies, a parametric study of 243 analysis cases, considering five parameters: (1) thermal expansion coefficient, (2) bridge length, (3) backfill height, (4) backfill stiffness, and (5) pile soil stiffness, was performed to established prediction models for abutment displacements over a bridge life. The parametric study results revealed that thermal expansion coefficient, bridge length, and pile-soil stiffness significantly influenced the abutment displacement. Bridge length parameter significantly influenced the abutment top displacement at the centroid of the superstructure, which is similar to the free expansion analysis results. Developed prediction model can be used for a preliminary design of integral abutment bridges.

Reduced Model of the PC Segmental Multispan Bridge Constructed by Free Cantilever Method for Investigation of Deflection and Member Force (캔틸레버공법 PC 세그멘탈 다경간 교량의 처짐 및 단면력 검토를 위한 축소모델에 관한 연구)

  • Lee, Jae Hoon;Lee, Myeong-Jae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.13 no.4
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    • pp.1-13
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    • 1993
  • In design of prestressed concrete structures, structural analysis is performed normally several times for selection of adequate sectional dimension and tendon amount. Especially for precast segmental multi-span bridges. time consuming structural analysis process due to time dependent material properties and structural system change could be effectively reduced by use of a reduced-span bridge model. 5-span and 3-span bridges are selected as reduced-span models for the 10-span full bridge to investigate the acceptability in practical design. The analytical results of deflection, total moment, statical moment, and ultimate moment of the reduced span-models are compared with those of the 10-span full bridge. Application of the load factors to structural analysis for ultimate moment calculation in prestressed concrete is reviewed and a rational method is proposed.

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Parametric Study on Steel composite Girder bridges for HONAM High-Speed Railway Considering Criteria Requirement of Dynamic Response (호남고속철도 동적 안정성 요구 조건을 고려한 강합성 거더교의 변수 연구)

  • Cho, Sun-Kyu;Jung, Han-Ouk;Kim, Sung-Il
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.1370-1378
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    • 2007
  • High speed railway bridge is affected on safety of bridge by dynamic amplification effect, when dynamic response of bridge is equal to effect cycle load for rolling stock axle according to high speed operation train. And excessive deformation of structure has negative effect on operation safety of train and comfort of passenger due to fluctuation of wheel load by torsion of track etc. and decrease of contact force on vehicle wheel-rail. To ensure the safety of track and train operation safety, it is have to perform the study on resonance and deformation of structure. That criteria and requirement of railway bridge is limitation of vertical acceleration on deck for dynamic behavior of structure, contact of vehicle wheel and rail, limitation of face distortion and rotation angle of end deck, and limitation of vertical displacement by train. Unlike KYEONGBU High Speed Railway, New constructed HONAM High Speed Railway have to applied the new requirement for dynamic behavior safety according to change of condition which is type of ballast (slab ballast), interval of track, and actual rolling stock load. Therefore, in this paper, it was conformed the dynamic characteristic due to parameter, which related with above mentioned criteria, for steel composite bridges.

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Evaluation of Performance Simulation for Bridge Substructure Due to Types of Scour (지반세굴 유형에 따른 교량 하부구조의 해석적 거동 예측)

  • Jung, Wooyoung;Yune, Chanyoung;Lee, Ilhwa
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.3
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    • pp.5-11
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    • 2013
  • The primary objective of this research is to evaluate the behavior of a bridge substructure subjected to scouring during flood. A finite element (FE) study was carried out on a substructure modeled using the standard section specified for highway bridges. The three-dimensional FE model consists of non-linear springs with tri-axial load capacities at the base in order to consider the loss of bearing capacity of the substructure by local scour phenomenon. Various time varying loading conditions and scouring patterns were considered in the analysis. The results indicate a change in the structural behavior of substructure depending on the eroded area and pattern. The outcome of this research will be useful to suggest basic design guidelines for ground sills of the bridge substructure.

Resonance Phenomenon according to the relationship between Span Length of the Bridge and Effective Beating Interval of High-Speed Train (교량의 지간장과 고속전철하중 유효타격간격 사이의 관계에 따른 공진현상)

  • 김성일;곽종원;장승필
    • Journal of the Earthquake Engineering Society of Korea
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    • v.3 no.2
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    • pp.67-76
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    • 1999
  • Resonance of the bridge can be occurred with the coincidence between a natural frequency of the bridge and a crossing frequency of moving loads which is determined from the speed and effective beating interval of the vehicle. In case of the railway bridge, the effective beating interval of the vehicle is fixed under the passage of specific trains. In the present study, resonance and cancellation of the bridge subjected to moving high-speed train are analyzed with the variations of span length. A steel-concrete composite railway bridge is idealized by the combinations of plate elements and space frame elements. High-speed train is idealized with moving constant forces and a 3-dimensional full modelling. From analyzing dynamic responses of D.M.F of vertical displacement, maximum vertical acceleration of the slab, and end rotation according to the variations of span length of the bridge, design criteria of span length of the bridge which satisfies dynamic safety is discussed.

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Development of an Assumed Strain Shell Element for the Three Dimensional Construction Stage Analysis of PSC Bridge (PSC 교량의 3차원 시공 중 해석기법을 위한 가정된 변형률 쉘 요소 개발)

  • Kim, Ki-Du;Song, Sak Suthasupradit;Hwang, Hyun-Jin;Park, Jae-Gyun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.3
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    • pp.108-117
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    • 2010
  • The frame element is commonly used for construction stage analysis PSC bridges. However, the frame element does not show sufficient information in the curved PSC box bridges. For the case of curved PSC bridges, the deformations in the inner and outer web are different. In this case, the different jacking forces are required in the inner and outer webs. And it is impossible to calculate different jacking forces in the inner and outer webs if we use the frame element for construction stage analysis. In order to overcome this problem, the use of shell element is essential for a three-dimensional construction stage analysis of PSC bridges. In the following, the formulation of an assumed strain shell element and its application of PSC box girder bridge analysis are presented.