• Title/Summary/Keyword: composite bridges

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A Fundamental Study on Effective Width Evaluation of Laminated Composite Box Girder (복합적층 박스거더의 유효폭 산정을 위한 기초연구)

  • Chun, Kyoung-Sik;Ji, Hyo-Seon;Park, Won-Tae
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.6 no.3
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    • pp.26-31
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    • 2015
  • The domestic and foreign specifications presented the effective width based on flange length to width ratio only. The existing paper on the effective width grasped of the effect of span, load type and cross-section properties, but localized steel bridges. Recently, The studies are going on in progress for the application of fiber reinforced composite material in construction field. Therefore, it is required to optimum design that have a good grasp the deformation characteristic of the displacements and stresses distribution and predict variation of the effective width for serviceability loading. This research addresses the effective width of all composite material box girder bridges using the finite element method. The characteristics of the effective width of composite structures may vary according to several causes, e.g., change of fibers, aspect, etc. Parametric studies were conducted to determine the effective width on the stress elastic analysis of all composite materials box bridges, with interesting observations. The various results through numerical analysis will present an important document for construct all composite material bridges.

Enhancing fire resistance of steel bridges through composite action

  • Kodur, Venkatesh K.R.;Gil, Augusto
    • Steel and Composite Structures
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    • v.43 no.3
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    • pp.353-362
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    • 2022
  • Bridge fire hazard has become a growing concern over the last decade due to the rapid increase of ground transportation of hazardous materials and resulting fire incidents. The lack of fire safety provisions in steel bridges can be a significant issue owing steel thermal properties that lead to fast degradation of steel properties at elevated temperatures. Alternatively, the development of composite action between steel girders and concrete decks can increase the fire resistance of steel bridges and meet fire safety requirements in some applications. This paper reviews the fire problem in steel bridges and the fire behavior of composite steel-concrete bridge girders. A numerical model is developed to trace the fire response of a typical bridge girder and is validated using measurements from fire tests. The selected bridge girder is composed by a hot rolled steel section strengthened with bearing stiffeners at midspan and supports. A concrete slab sitting on the top of the girder is connected to the slab through shear studs to provide full composite action. The validated numerical model was used to investigate the fire resistance of real scale bridge girders and the effect of the composite action under different scenarios (standard and hydrocarbon fires). Results showed that composite action can significantly increase the fire resistance of steel bridge girders. Besides, fire severity played an important role in the fire behavior of composite girders and both factors should be taken into consideration in the design of steel bridges for fire safety.

Plastic load bearing capacity of multispan composite highway bridges with longitudinally stiffened webs

  • Unterweger, Harald;Lechner, Andreas;Greiner, Richard
    • Steel and Composite Structures
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    • v.11 no.1
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    • pp.1-19
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    • 2011
  • The introduction of the Eurocodes makes plastic design criteria available also for composite bridges, leading to more economical solutions compared with previous elastic design rules. Particularly for refurbishment old bridges with higher actual traffic loads, up to date outside the scope of the Eurocodes, strengthening should therefore be avoidable or at least be necessary only to a minor extent. For bridges with smaller spans and compact cross sections, the plastic load bearing capacity is clearly justified. In this work, however, the focus is placed on long span continuous composite bridges with deep, longitudinally stiffened girders, susceptible to local buckling. In a first step, the elastic - plastic cross section capacity of the main girder in bending is studied as an isolated case, based on high preloads acting on the steel girder only, due to the common assembling procedure without scaffolding. In a second step, the effects on the whole structure are studied, because utilising the plastic section capacity at midspan leads to a redistribution of internal forces to the supports. Based on the comprehensive study of an old, actual strengthened composite bridge, some limitations for plastic design are identified. Moreover, fully plastic design will sometimes need additional global analysis. Practical recommendations are given for design purposes.

Development of a System of Temporary Arch Bridges by Using Snap-fit GFRP Composite Decks (조립식 복합소재 아치구조를 이용한 가교 시스템 개발)

  • Cho, Yong-Sang;Lee, Sung-Woo;Hong, Kee-Jeung
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2008.04a
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    • pp.276-281
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    • 2008
  • Glass-fiber reinforced polyester(GFRP) composite material is a promising alternative to existing construction materials such as steel, concrete and wood. One of passible applications of GFRP composite material is to build temporary bridges by assembling GFRP composite decks. In this paper, we develop a system of temporary arch bridges that can be built by easy assembling of GFRP composite decks. For this purpose, several types of temporary arch bridges are suggested and verified by FE analysis.

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Design of Longitudinal Prestress of Precast Decks in Continuous Bridges (연속교 프리캐스트 바닥판의 교축방향 프리스트레스 설계)

  • Shim, Chang-Su;Kim, Hyun-Ho;Ha, Tae-Yul;Jeon, Seung-Min
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05a
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    • pp.406-409
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    • 2006
  • Serviceability resign is required to control the cracking at the joint of precast decks having longitudinal prestress in continuous composite bridges. Especially, details of twin girder bridges are complex not only due to main reinforcements and transverse prestress for the resign of long-span concrete slabs but also due to shear pockets for obtaining the composite action. This paper suggests the design guidelines for the magnitude of the effective prestress and for the selection of filling materials and their requirements in order to use precast decks for twin-girder continuous composite bridges. The necessary initial prestress was also evaluated through the long-term behavior analysis. From the analysis, existing design examples were revised and their effectiveness was estimated. When a filling material having bonding strength higher than the requirement is used in the region of high negative moment, uniform configuration of longitudinal prestressing steels along the whole span length of continuous composite bridges can be achieved resulting in simplification of details and enhancement of the construction costs.

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Dynamic response of steel-concrete composite bridges loaded by high-speed train

  • Podworna, Monika
    • Structural Engineering and Mechanics
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    • v.62 no.2
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    • pp.179-196
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    • 2017
  • The paper focuses on dynamic analyses of a series of simply-supported symmetric composite steel-concrete bridges loaded by an ICE-3 train moving at high speeds up to 300 km/h. The series includes five bridges with span lengths ranging from 15 m to 27 m, with repeatable geometry of the superstructures. The objects, designed according to Polish standards valid from 1980s to 2010, are modelled on the bridges serviced on the Central Main Line in Poland since 1980s. The advanced, two-dimensional, physically nonlinear model of the bridge-track structure-high-speed train system takes into account unilateral nonlinear wheel-rail contact according to Hertz's theory and random vertical track irregularities equal for both rails. The analyses are focused on the influence of random track irregularities on dynamic response of composite steel-concrete bridges loaded by an ICE-3 train. It has been pointed out that certain restrictions on the train speed and on vertical track irregularities should be imposed.

Effects of Interactions between the Concrete Deck and Steel Girders on the Dynamic Behavior of Simply Supported Skew Bridges (주형과 상판과의 상호작용이 단순 사교의 동적거동에 미치는 영향)

  • Moon, Seong-Kwon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.20 no.5
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    • pp.593-604
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    • 2007
  • Although composite construction has more mechanical advantages compared to noncomposite construction, the design of noncomposite construction for skew bridges with large skew angels has been often checked because composite construction may cause large stresses in the bridge deck. In this study, the analytical model considered dynamic behaviors for noncomposite skew bridges was proposed. Using the proposed analytical model, the validity of the application of noncomposite construction to skew bridges was checked. Also, the effects of interactions between the concrete deck and steel girders such as composite construction, partial composite construction, and noncomposite construction on the dynamic characteristics and dynamic behaviors of simply supported skew bridges were investigated. A series of parametric studies for the total 27 skew bridges was conducted with respect to parameters such as girder spacing, skew angle, and deck aspect ratio. Although the slip at the interfaces between the concrete deck and steel girders results in the reduction of seismic total base shear in the transverse direction due to period elongation, it causes an undesirable behavior of skew bridges by the modification in mode shapes and distributions of stiffness. Shear connectors placed by minimum requirements for partial composite action have an effect on reducing the girder stresses and deck stresses; except case of some skew bridges, the magnitude of the girder stresses and deck stresses obtained from partial composite skew bridges is similar to or slightly more than those acquired from composite skew bridges.

Analytical and Experimental Studies on Partially Composite of Steel-Plate Girder Bridges Using Slab Anchors (바닥판 앵커를 사용한 플레이트거더교의 부분합성에 관한 해석 및 실험 연구)

  • Han, Sang Yun;Park, Nam Hoi;Yoon, Ki Young;Kang, Young Jong
    • Journal of Korean Society of Steel Construction
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    • v.16 no.3 s.70
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    • pp.325-332
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    • 2004
  • Cross sections of steel-plate girder bridges are divided into three cross sections of non-composite, partially composite, and fully composite sections, according to their composite characteristics. The Korean provision for the partially and fully composite sections specifies general usage of the stud of shear connectors, whereas the one for the non-composite section specifies empirical usage of slab anchors. However, the actual behavior of the cross sections of steel-plate girder bridges using slab anchors is close not to the non-composite action, but to the partially composite action. Therefore analytical and experimental studies on partial composites of steel-plate girder bridges using slab anchors are performed in this study. Intial stiffness of the slab anchor is obtained by the experimental study for the first time, and the composite characteristic of simple-span and two-span continuous steel-plate girder bridges is investigated by the finite element analyses for the second time. Based on the obtained initial stiffness, the reduction effect of tensile stresses in the concrete-slab on the intermediate support of the continuous bridge is also considered herein.

Composite deck construction for the rehabilitation of motorway bridges

  • Greiner, R.;Ofner, R.;Unterweger, H.
    • Steel and Composite Structures
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    • v.2 no.1
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    • pp.67-84
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    • 2002
  • Traffic decks of steel or composite motorway bridges sometimes provide the opportunity of using the composite action between an existing steel deck and a reinforced concrete plate (RC plate) in the process of rehabilitation, i.e., to increase the load-carrying capacity of the deck for concentrated traffic loads. The steel decks may be orthotropic decks or also unstiffened steel plates, which during the rehabilitation are connected with the RC plate by shear studs, such developing an improved local load distribution by the joint behaviour of the two plate elements. Investigations carried out, both experimentally and numerically, were performed in order to quantitatively assess the combined static behaviour and to qualitatively verify the usability of the structure for dynamic loading. The paper reports on the testing, the numerical simulation as well as the comparison of the results. Conclusions drawn for practical design indicated that the static behaviour of these structures may be very efficient and can also be analysed numerically. Further, the results gave evidence of a highly robust behaviour under fatigue equivalent cyclic traffic loading.

Numerical model for nonlinear analysis of composite concrete-steel-masonry bridges

  • Baloevic, Goran;Radnic, Jure;Grgic, Nikola;Matesan, Domagoj;Smilovic, Marija
    • Coupled systems mechanics
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    • v.5 no.1
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    • pp.1-20
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    • 2016
  • This paper firstly briefly describes developed numerical model for both static and dynamic analysis of planar structures made of concrete, steel and masonry. The model can simulate the main nonlinearity of such individual and composite structures. The model is quite simple and based on a small number of material parameters. After that, three real composite concrete-steel-masonry bridges were analyzed using the presented numerical model. It was concluded that the model can be useful in practical analysis of composite bridges. However, future verifications of the presented numerical model are desirable.