• Title, Summary, Keyword: psc girder

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An Experimental Study on the Precast Segmented PSC Girder with I-Shape and Box-Shape Cross-Section (I형 단면과 BOX형 단면을 갖는 프리캐스트 분절 PSC 거더의 실험적 연구)

  • Kim, Sun-Hee;Lee, Seng-Hoo;Park, Joon-Seok;Cheon, Jinuk;Yoon, Soon-Jong
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.6 no.2
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    • pp.8-16
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    • 2015
  • Prestressed concrete (PSC) is a method in which prestressed tendon is placed inside and/or outside the reinforced concrete member and the compressive force applied to the concrete in advance to enhance the engineering properties of concrete member which is weak under tension. In this paper we suggested the precast PSC girder assembled with segments of portable size and weight at the factory. The segments of precast PSC girder will be delivered and assembled as a unit of PSC girder at the site. Consequently, we suggested new-type of precast segmented PSC girder with different shapes of segment cross-section (i.e., I-shape, Box-shape). To mitigate the problems associated with the field splice between the segments of precast PSC girder anchor system is attached near the neutral axis of the girder and relatively uniform compression throughout the girder cross-section is applied. Prior to the experimental investigation, analytical investigation on the structural behavior of precast PSC girder was performed and the serviceability (deflection) and safety (strength) of the girder were confirmed. In addition, 4-point bending test on the girder was conducted to investigate the structural performance under bending. From the experimental investigation, it was found that the precast PSC girder spliced with 3 and 5 segments has sufficient in serviceability and safety conditions and it was also observed that the point where the segments spliced has no defects and the girder behaves as a unit.

Analysis of Lateral Behavior of PSC Bridge Girders under Wind Load During Construction (시공 중 풍하중에 의한 PSC 교량 거더의 횡방향 거동 해석)

  • Lee, Jong-Han;Kim, Kyung Hwan;Cho, Baiksoon
    • Journal of the Korea Concrete Institute
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    • v.27 no.4
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    • pp.377-385
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    • 2015
  • The span-lengthening of PSC I girder has increased the risk of lateral instability of the girder with the increases in the aspect ratio and self-weight of the girder. Recently, collapses of PSC I girder during construction raise the necessity of evaluating the lateral instability of the girder. Thus, the present study evaluated the lateral behavior and instability of PSC I girders under wind load, regarded as one of the main causes of the roll-over collapse during construction. Lateral instability of the girder is mainly dependent on the length of the girder and the stiffness of the support. The analysis results of this study showed the decrease in the critical wind load and the increase in the critical deformation and angle of the girder, leading to the lateral instability of the girder. Finally, this study proposed analytical equations that can predict the critical amount of wind load and lateral deformation of the girder, which would provide quantitative management values to maintain lateral stability of PSC I girder during construction.

Evaluation of the Load Carrying Capacity of Existing Bridges with Long Span Hollow Web Prestressed Concrete Girder by Static Load Test (정적재하시험을 통한 장경간 중공 웨브 PSC 거더교의 내하력 평가)

  • Kim, Seong-Kyum;Jang, Pan-Ki;Jang, Il-Young
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.3
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    • pp.97-102
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    • 2018
  • Conventional PSC I type girders were adversely affected by the self - weight of concrete, anchorage, prestressing. In order to overcome this problem, PSC girder was constructed with a hollow in the web and developed a hollow web PSC type I girder which is applicable to 50 - 70m span by multistage stressing and then actually long span hollow web PSC girder bridge was constructed. In this study, the results of Static Load Test and the Finite Element Analysis of the hollow web PSC I girder bridges were compared and analyzed, and the Load Carrying Capacity and safety of PSC girder bridges were evaluated. The Static Load Test and the numerical analysis results of this bridge showed similar tendency and the behavior of the hollow web PSC I girder was well simulated. The entire girders of the bridges had sufficient Load Carrying Capacity under the live load design condition and the bridges satisfied the safety and confirmed the appropriateness of the construction.

Shrinkage and Creep Effects on Continuous Prestressed Concrete Girder Bridges (연속 프리스트레스트 콘크리트 거더교에서 건조수축과 크리프의 영향)

  • Cho, Sun-Kyu;Youn, Seok-Goo;Lee, Jong-Min;Choi, Yun-Wang;Chung, Jee-Seung
    • Proceedings of the Korea Concrete Institute Conference
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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.

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An Experimental Study for Structural Safety Evaluation of PSC Box Girder Bridge with FRP Struts (FRP 스트럿을 가진 PSC 박스거더교의 구조안전성 평가를 위한 실험 연구)

  • Song, Jae-Joon;Park, Jong-Hwa;Park, Kyung-Hoon;Jo, Byung-Wan
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.12 no.6
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    • pp.205-213
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    • 2008
  • The structure of PSC box girder with FRP strut has a form of supporting the cantilever part in the widened upper slab by modifying the existing PSC box girder efficiently, and it is able to build an economical and aesthetically pleasing bridge as it reduces the size of the lower structure by reducing the self-weight of the upper structure. In this research, loading test of PSC Box Girder using full-scale mock-up was conducted and FEM analysis was performed. By comparing results, structural safety of the FRP strut and the upper slab following application of the strut in the PSC Box Girder Bridge were evaluated.

Optimum Design of Prestressed Concrete Girder Railway Bridge (프리스트레스트 콘크리트 거더 철도교의 최적설계)

  • Lee Jong-Min;Seo Dong-Joo;Lee Tae-Gyun;Lee Joung-Sun;Cho Sun-Kyu
    • Journal of the Korean Society for Railway
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    • v.8 no.3
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    • pp.267-275
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    • 2005
  • Prestressed concrete girder(PSC girder) bridges have been used widely at the railway as well as highway because they are great in the functional and economical efficiency. Also they have the advantage of convenience of design and construction. However it could be easily verified that the section of PSC girder is excessive design, which has much redundancy against design loads. Thus, in this paper the formulation of the optimum design for PSC girder railway bridge is suggested and dominant design variables and constraints are inquired as performing the optimum design. In order to effective optimum design, design variables are formulated as PSC girder sectional dimension and girder space. The objective is adopted as total cost of PSC girder railway bridge. Also, constraints are formulated according to Korean railway design specification and considering construction-ability such as PS anchorage and girder space. Using the proposed optimum design system, optimum PSC girder railway bridge design has been performed. And from the results of analysis it is suggested to denote the optimum section which satisfies the structural safety and economical efficiency all together.

Assessment for Extending Span Ranges of PSC Girder Bridges : II. Application to a Sample Bridge (PSC 거더교의 장경간화 평가 기법 : II. 예제 분석)

  • Jeon, Se Jin
    • Journal of The Korean Society of Civil Engineers
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    • v.29 no.3A
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    • pp.243-250
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    • 2009
  • The purpose of this study is to investigate several strategies that can be used to extend the span of conventional PSC girder bridge and to propose a systematic procedure to evaluate the effect of each strategy on the span. In the preceding companion paper, fundamental equations were derived which constitute the assessment graphs and a possible domain for the design. Quantitative evaluation for extension of the span follows here by adopting a sample PSC girder bridge. It apparently shows a number of advantages of the proposed scheme in finding out why and how each strategy contributes to the span extension and in suggesting further improvement for a longer span. The results imply that increasing the strength of a girder, the multistage prestressing with the secondary tendons prestressed before composite action with a deck, and Decked PSC girder are very effective among the strategies examined. It is expected that the span of the PSC girder bridge can be well extended up to 50 m to 70 m which corresponds to a span of the conventional box girder bridges.

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Flexural Behaviors of PSC Composite Girders in Negative Moment Regions (콘크리트 충전 강관을 갖는 프리스트레스트 합성거더의 부모멘트 구간 거동)

  • Kang, Byeong-Su;Ju, Young-Tae;Lee, Yong-Hak
    • Journal of the Korea Concrete Institute
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    • v.18 no.2
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    • pp.169-176
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    • 2006
  • Prestressed composite girder with concrete infilled steel tubes(PSC-CFT girder) is new type of bridge girder which enhances the resisting capacities due to the double composite action of PSC composite girder and concrete infilled tube. The flexural behaviors of PSC-CFT girder in the negative moment regions are investigated based on the experimental observations recently performed on two of 3.6m long specimens. The mechanical and structural roles and failure mechanism of the composite action are discussed through comparing the test results with those numerically predicted by the three methods of one and three-dimensional nonlinear finite element analysis, and section analysis method.

A Study on the Design Parameters of the PSC I-Type Girders for Long Span Bridges (장지간 교량을 위한 PSC-I형 거더의 단면 설계변수 연구)

  • 심종성;오홍섭;김민수
    • Journal of the Korea Concrete Institute
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    • v.12 no.6
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    • pp.13-22
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    • 2000
  • In order to resolve the problem of increasing traffic entailed by the economic development, road system is reorganization and new highways are built, and long span bridges over 40m are being constructed in environmental and aesthetic considerations. Most long span bridges that are currently being constructed are in general steel box girder and preflex girder bridges; however these types of breiges are less efficiency than PSC I-type girder bridges in terms of construction cost and maintenance. Therefore, in these study, structural efficiency of PSC I-type girders based on section parameters, concrete compressive strength and other design parameter is observed to develope new PSC I-type girder for long span bridges. As a results of analysis, most important design parameters that control the stress of the girder are found to be the top flange width and the height of girder. In this light, the relationship between the two variables is determined and cross-section details of the girder that most appropriates for the long span bridges are proposed. The use of high strength concrete appears to increase the general design span however the increase rate of the span from increasing concrete ultimate strength appears to be reduced depending on the span. Also, the optimal girder spacing is determined through the parameter studies of design span using the proposed girder.

Assessment for Extending Span Ranges of PSC Girder Bridges : I. Proposed Strategy to Estimate the Spans (PSC 거더교의 장경간화 평가 기법 : I. 경간 평가 기법의 제안)

  • Jeon, Se Jin;Choi, Myoung Sung;Kim, Young Jin
    • Journal of The Korean Society of Civil Engineers
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    • v.29 no.3A
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    • pp.235-241
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    • 2009
  • PSC girder bridge is known to be more economical than other types of bridges and has been usually applied to a span range of 25 m to 35 m according to the standard shapes for highway bridges in Korea. The spans of the recently developed new types of PSC girders are also limited to 50 m at most. In this study, therefore, feasibility of the long-span PSC girder that reaches more than 50 m is investigated by applying several strategies from the perspectives of materials, design and construction. A systematic procedure is proposed that can be used to assess the effect of each strategy on the span. The proposed scheme adopts a graphical approach that represents a relationship between the number of prestressing tendons and the span, and is derived on a basis of safety assessment equations of the girder in each stage of fabrication and in service. In the companion paper, the amount of span extension is quantitatively evaluated by applying the proposed scheme into a sample PSC girder bridge.

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