• Title/Summary/Keyword: IT girder

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Life Cycle Cost Analysis of SCP Composite Girder Bridge for Railroad (철도용 SCP합성거더교의 LCC 분석에 관한 연구)

  • Kim, Dae-Sung;Cho, Sun-Kyu;Kwon, Chek;Choi, Young-Min
    • Journal of the Korean Society for Railway
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    • v.9 no.2 s.33
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    • pp.244-249
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    • 2006
  • Recently, the SCP(Steel Confined Prestressed concrete) composite girders are developed to improve the characteristic such as displacement, vibration, and heavy dead load due to influence of self weight, and inefficiency of steel section of exiting girder-type railroad bridges. It is needed to verify the economical effciency of newly developed SCP composite girder bridge compared with the conventional girder-type bridges. In this paper, LCC analysis for alternative railroad bridges Is performed and its technique based on level of risk(probability of failure) is suggested. From the results, it may be stated that SCP composite girder bridge is more economical than a conventional one.

A Study of Optimum Section of PSC Girder Railway Bridge according to Variation of Span Length (지간장 변화에 따른 프리스트레스트 콘크리트 거더 철도교의 최적단면에 관한 연구)

  • Cho Sun-Kyu;Kim Su-Hyun;Lee Jong-Min;Lee Tae-Gyun
    • Proceedings of the KSR Conference
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    • 2005.11a
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    • pp.1209-1214
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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. Generally, the PSC girder railway bridges with span length 25m are adopted in the country and it could be easily verified that the section of PSC girder using railway bridge is excessive design, which has much redundancy against design loads. Thus, in this paper the optimum design for PSC girder railway bridge with span length 30m is 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.

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Girder Distribution Model for Existing Short and Medium Span Steel Girder Bridges (단·중경간 강형교 거더의 횡분배 모델)

  • Eom, Jun-Sik;Nowak, Andrzej S.;Lho, Byeong-Cheol
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.7 no.2
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    • pp.219-229
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    • 2003
  • The objective of this work is to verify the Code specified girder distribution factors for short and medium span bridges. To accomplish this objective, field tests were carried out on seventeen simply supported highway bridges. This paper presents the procedure and results of field tests that were performed to verify girder distribution factors. Finite Element analyses previously performed at the University of Michigan indicated that in most cases currently used girder distribution factors specified in AASHTO Codes are too conservative. However, these studies also showed that for short spans and short girder spacings, the girder distribution factors can be too permissive. Therefore, this paper focused on experimental evaluation of girder distribution factors for short and medium span steel girder bridges. The results were compared with the distribution factors specified by AASHTO Standard (2000) and AASHTO LRFD Code (1998). It has been found that the measured girder distribution factors are lower than AASHTO values in most cases, and sometimes the code specified values are overly conservative. The research work involved formulation of the testing procedure, selection of structure, installation of equipment, measurements, and interpretation of the results.

Evaluation of Structural Safety about the Bending and Torsion of Superstructure of the Fish-bone Girder Pier (경골잔교 상부구조의 휨 및 비틀림에 대한 구조 안전성 검토)

  • Ham, Gyu-Sung;Lim, Nam-Hyoung;Park, Jong-Sup;Yoon, Ki-Yong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.4
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    • pp.2000-2005
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    • 2013
  • In this paper, the design load acting on a main girder(spine girder) of fish-bone girder pier is proposed. In order to check the structural safety, numerical analyses using finite element program ABAQUS are performed. It is found that the main girder is affected by a torsional behavior as well as a bending behavior and the major influence loading is the torsional loading. Also, from the stress evaluation of the chosen cross section of the main girder, chosen fish-bone girder pier is structurally safe.

Study of Bridge Design of The Length-Depth Ratio is 34 (경간/형고비 34를 실현한 IPC 거더교의 연구)

  • 한만엽;곽창현
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.839-844
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    • 2001
  • The length-depth ratio of the preflex and PSC girder is very important variable. But PSC girder is very difficult to reduce the depth. If the bridge that girder depth is most important variable, then generally the great part of engineers are use the preflex girder that more expensive method then PSC girder. This paper introduce the design example that replace the preflex girder with the IPC girder The bridge span is 44m, and depth is 1.15m. The depth is restrained in 1.15m by several conditions. And it is compare preflex with IPC girder in semi condition. These two girders are very different in economy and execution. So, this paper present more economic and easy construction method.

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Aerodynamic Flutter Control for Typical Girder Sections of Long-Span Cable-Supported Bridges

  • Yang, Yongxin;Ge, Yaojun
    • Wind and Structures
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    • v.12 no.3
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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.

Performance Improvement on Plate Girder Bridges Through Continuous Welded Rail (판형교 장대화에 따른 성능 개선)

  • Min, Kyung-Joo;Bahn, Gul-Yong;Ryu, Yeon-Jong
    • Proceedings of the KSR Conference
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    • 2007.05a
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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.

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A Study on the Applicability of SCP Girder to Continuous Bridges (SCP 합성거더의 연속교 적용에 관한 연구)

  • Kim, Jung Ho;Lee, Sang Yoon;Park, Kyung Hoon;Hwang, Yoon Koog;Yoo, Gun Woo
    • Journal of Korean Society of Steel Construction
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    • v.18 no.1
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    • pp.101-111
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    • 2006
  • The SCP girder, which compensates for the shortcomings of conventional girders through the effective composition of concrete, steel, and PS tendon, has recently been developed and applied on real bridges. Developed as a simple-support type, it may be applied on simple-support and continuous bridges by connecting the simple-support SCP girders to the interior supports. A continuous SCP girder, which has structural and cost advantages over the simple-support SCP girder, is proposed in this study. Likewise proposed herein is a new method of constructing a continuous SCP girder, using segments of the girder sequentially. A two-span, half-scale specimen was designed and constructed to verify the propriety of the continuous SCP girder bridge. A static load test was also carried out, using this specimen, to examine the behavior of the continuous SCP girder. Based on the results of the study, it is expected that the continuous bridge that uses the continuous SCP girder can guarantee the structural safety of the simple-support SCP girder.

Buckling Behaviors of Plate Girder with Corrugated Steel Web (파형 복부판을 갖는 플레이트 거더의 좌굴거동)

  • Ji, Hyo-Seon
    • Journal of Korean Society of Steel Construction
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    • v.23 no.2
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    • pp.221-228
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    • 2011
  • Because steel plate girder bridge has big slenderness ratio, buckling is a major design factor. The objective of this study is to analyze the buckling behaviors of plate girder with I-girder and corrugated steel web and to examine the advantages of plate girder with corrugated steel web. Various parametric study according to the change of web height, web thickness, and load condition are examined. It is shown that plate girder with corrugated steel web is more effective than plate girder with I-girder and proper corrugated angle(${\theta}$) is $15^{\circ}{\sim}22^{\circ}$.

A Study on LIT Girder Performance Improvement (LIT 거더 성능 개선에 대한 연구)

  • Kim, Sung;Park, Sungjin
    • Journal of Urban Science
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    • v.11 no.2
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    • pp.19-24
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    • 2022
  • Conventional RC beams for crossing small and medium-sized rivers do not have a cross-sectional area, so the floating debris is accumulated and disasters such as damage to bridges occur. To improve this, the PSC method was invented. However, this also had problems such as transverse curvature, increase in dead weight due to cross-sectional shape, and negative moment generated during serialization, so it was necessary to develop a new type of girder. Therefore, it was intended to propose a LIT(Leton Interaction Thrust) girder bridge that is safer and has better performance than the conventional PSC girder with improved section efficiency. Unlike existing girder bridges, the LIT girder has the feature that the change in the strands of the entire girder occurs only in the vertical direction when the first tension is applied because the tendon arrangement is symmetrical by applying the raised portion. In addition, slab continuation generates a secondary moment that is advantageous to the continuous point, effectively controlling the negative moment and preventing the corrosion of the tendon. The dimensions of the cross section were determined, and the arrangement of the strands was designed to conduct structural analysis and detailed analysis. As a result of the structural analysis, the stress of the girder showed results within the allowable compressive stress, and the deflection showed the result within the allowable deflection. showed results. In addition, a detailed analysis was performed to examine the stress distribution around the girder body and the anchorage area and the stress distribution of the embossed portion, and as a result, the stress of the girder body due to the tension force showed a stable level.