• 복합신소재구조학회 논문집
• /
• 제6권3호
• /
• pp.26-31
• /
• 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.

• Steel and Composite Structures
• /
• 제43권3호
• /
• pp.353-362
• /
• 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.

• Steel and Composite Structures
• /
• 제11권1호
• /
• pp.1-19
• /
• 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.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2008년도 정기 학술대회
• /
• pp.276-281
• /
• 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.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
• /
• pp.406-409
• /
• 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.

• Structural Engineering and Mechanics
• /
• 제62권2호
• /
• pp.179-196
• /
• 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.

• 한국전산구조공학회논문집
• /
• 제20권5호
• /
• pp.593-604
• /
• 2007

합성형 사교는 비합성형 사교에 비해 역학적 측면에서 큰 장점을 지니고 있는 것이 사실이지만 사각이 심한 사교들의 경우 합성형 사교에 매우 큰 상판응력이 유발될 가능성이 있어 종종 이들 사교들에 대한 비합성형 설계가 검토되어지곤 한다. 본 연구에서는 동적해석이 가능한 비합성형 사교의 해석모델을 제안하고 이 해석모델들을 이용하여 사교들에 대한 비합성형의 적용 타당성을 검토하였다. 또한 주형과 상판과의 세 가지 상호작용(합성작용, 부분합성작용, 비합성작용)이 단순 판형사교들의 동적특성과 동적거동에 미치는 영향을 조사하였다. 주형간격, 사각, 상판 종횡비를 매개변수로 총 27개의 판형 사교들에 대한 일련의 연구를 수행하였다. 상판과 주형 경계면에서의 미끄러짐은 고유진동주기가 길어지는 현상을 유발하여 사교의 교축직각방향에 작용하는 전체밑면전단력의 크기를 감소시킬 수도 있지만 모드형장과 강성분포에 큰 영향을 미쳐 바람직하지 않은 사교 거동을 유발할 수도 있다. 부분합성작용의 최소 규정에 따라 설치된 전단연결재는 주형응력과 상판응력을 감소시키는 효과가 있다. 즉, 몇몇 사교의 경우를 제외하고는 전반적으로 부분합성형으로부터 구한 주형응력과 상판응력의 크기는 합성형 사교로부터 구한 관련 응력들의 크기와 유사하거나 약간 크게 나타난다.

• 한국강구조학회 논문집
• /
• 제16권3호통권70호
• /
• pp.325-332
• /
• 2004

강합성거더 교량의 단면은 강거더와 콘크리트 슬래브의 합성정도에 따라 각각 비합성, 부분합성 그리고 완전합성 단면들로 구분 할 수 있다. 국내의 경우 강합성거더 교량의 단면을 합성시키기 위하여 일반적으로 전단 연결재 중 스터드를 사용하도록 규정하고 있고, 진단 연결재가 없는 경우 즉 비합성 단면의 경우에는 바닥판 앵커를 설치하도록 경험적으로 규정하고 있다. 그러나 바닥판 앵커를 사용한 단면의 실제 거동은 비합성 거동이 아닌 부분합성의 거동을 나타낸다. 그러한 이유로 본 연구에서는 바닥판 앵커를 사용한 플레이트거더교의 부분합성에 관한 해석 및 실험연구를 수행하였다. 실험연구를 통해서 바닥판 앵커의 초기강성을 산정하였고, 해석연구를 통해서 바닥판 앵커를 사용한 단순 및 2경간 연속 플레이트거더교의 합성정도를 비교$\cdot$분석하였다. 또한, 실험에 의해 산정된 강성 값에 근거하여, 2경간 연속 플레이트거더교에 바닥판 앵커를 적용하였을 때 발생할 수 있는 내부지점부 콘크리트의 인장응력 저감 효과를 검토하였다.

• Steel and Composite Structures
• /
• 제2권1호
• /
• pp.67-84
• /
• 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.

• Coupled systems mechanics
• /
• 제5권1호
• /
• pp.1-20
• /
• 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.