• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.669-672
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• 2011

본 논문은 사하중 절감이 중요한 장지간 교량에 있어서 유리한 구조를 가지는 강바닥판의 성능 강화를 위한 수치해석 연구를 실시하였다. 이미 국내외에서는 다수의 강바닥판을 이용한 교량의 시공 사례가 많으며, 앞으로도 시공 또는 계획될 해상 장지간 교량에서도 강바닥판 교량의 사례가 많을 것으로 판단된다. 강바닥판 교량은 공기를 단축할 수 있으며, 들보의 높이가 작아서 날씬한 형상으로 할 수 있기 때문에 미관을 향상 시킬 수 있을 뿐만 아니라 가설 공사비를 절감시킬 수 있는 등 많은 장점을 갖고 있다. 하지만 강바닥판은 이상과 같이 장점을 갖는 구조이지만 비교적 얇은 강판을 복잡한 형상으로 용접하여 조립함에 용접 결함, 잔류응력, 면내 및 면외 변형의 발생 등의 문제점이 지적되고 있다. 따라서 외국에서는 강바닥판의 피로 손상에 대한 실험 및 연구로 많은 자료를 확보하고 있으며, 국내에서도 국내 현실에 맞는 강바닥판의 피로거동 및 피로강도 향상방안에 관한 연구가 더욱더 필요하다. 본 연구에서는 국내교량에 적용되고 있는 구조상세 및 구조해석을 실시하여 강바닥판의 피로거동과 응력 특성을 파악하고, 피로강도를 향상하는 방법으로 Bulkhead Plate와 수직리브 형상 및 부착에 따른 거동을 분석하고, 최적상세를 도출하여 강바닥판의 적극적인 활용화에 그 목적이 있다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.627-630
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• 2011

강바닥판 교면포장의 파손방지를 위하여 윤하중을 받는 강박스형 강바닥판의 변형도를 조사하였다. 이를 위하여 강바닥판과 거더는 쉘요소, 포장은 고체요소로 각각 모델링하고 정밀유한요소해석을 수행하였다. 탄성비, 포장의 두께, 그리고 방수층의 두께 및 물성치 변화에 따른 교면 포장된 강바닥판의 계면, 포장상면 그리고 포장 두께에서의 교축, 교직 그리고 중력방향에 대한 변형도를 측정하였다. 그 결과 방수층의 두께 및 물성치의 변화에 대해 강바닥판과 포장은 거의 영향을 받지 않았고, 대체적으로 포장의 두께가 강바닥판과 포장사이의 탄성비보다 포장의 변형에 더 기인하는 것으로 나타났다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.3
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• pp.41-50
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• 2012

Improvement of steel material quality made fatigue problems more critical than failure of the material itself. In many cases, cracks on the welded parts of steel deck bridges are reported against the failure of steel materials. And the cracks are caused by alternate stress on the welded parts due to live loads on the bridge. The range of alternate stress on the welded part is related to property of the sections which compose othortropic steel deck. Othortropic steel deck is mainly composed of deck plate, ribs and floor beams, wearing surface, etc. In this paper, a methology to estimate the alternate stress for pthortropic steel deck using Pelikan-Esslinger method and signed Von-Mises equivalent stress is proposed first. Parametric study served references for fatigue stresses when designing or repairing othortropic steel deck bridges, by analyzing relationship between alternate stress range and properties of steel deck members.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.6
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• pp.46-54
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• 2015

Base on Korean design code, previous design code had not considered the effect of pavement on the orthotropic steel deck, however recent design code (Limit State Design Method, 2012) allowed to consider the effect of pavement on the orthotropic steel deck, and efforts to apply the stiffness of pavement to the deck continue. Meanwhile, research on the effect of ultra thin bridge deck overlay on the orthotropic steel deck is inadequate, previous study was limited in about fatigue stress and performance between pavement layer and the orthotropic steel deck. In this study, according to changing of pavement layer stiffness application, pavement materials, pavement thickness and steel deck thickness, analysis of deflection. In addition to base on this result, consider effectiveness of ultra-thin pavement stiffness application on the orthotropic steel deck.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.4
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• pp.439-447
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• 2011

Longitudinal cracks due to traffic truck loadings that are caused by local deformations of steel orthotropic bridge decks are sometimes observed in the wearing surface. So, underlying causes of the longitudinal pavement crack induced by structural behaviors of steel decks are investigated in this study. For this purpose, The rational finite element model of the steel deck and the pavement having the box girder is developed and a parametric study is performed by varying thickness or elastic modulus ratios of both the steel deck plate and the pavement. As a result, a large tensile strain above the webs of the u-rib and the box girder, which becomes the main cause of the cracks of the pavement, is detected from variation of the normal strain component of the wearing surface in the transverse direction.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.5
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• pp.653-660
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• 2007

Since the temperature of asphalt for deck plate of steel bridge during paying procedure is relatively high as $240^{\circ}C\;to\;260^{\circ}C$, the temperature of deck plate of bridge rises mere than $100^{\circ}C$ and excessive displacement and stress could occur. In order to avoid undesirable failure of base plate and determine the optimal pavement pattern, a thorough thermal analysis is needed. General structural model which is made of beam and plate element should be modified for transient heat transfer analysis; asphalt pavement material and convection effect on surface of structure need to be added. A new technique with the Equivalent Heat Source (EHS) for numerical thermal analysis for steel bridge under thermal load of Guss asphalt pavement is proposed. Since plate/beam elements which were generally used for structural analysis for bridge cannot explain convection effect easily on plate/beam surface, EHS which is determined based on calculated temperature with convection effect is used. To verify the EHS proposed in this study, numerical analyses with plate elements are performed and the results are compared with estimated temperatures. EHS might be used for other thermal analyses of steel bridge such as welding residual stress analysis and bridge fire analysis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.2
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• pp.98-106
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• 2011

The deck of steel box girder bridges is composed of deck plate, longitudinal rib, and transverse ribs. The orthotropic steel decks have high possibility to fatigue damage due to numbers of welded connection part, the heavy contact loadings, and the increase of repeated loadings. Generally, the local stress by the repeated loadings of heavy vehicles causes the orthotropic steel deck bridge to fatigue cracks. The increase of traffic volume and heavy vehicle loadings are promoted the possibility of fatigue cracks. Thus, it is important to exactly evaluate the structural behavior of bridge considering the contact loading area of heavy vehicles and real load patterns of heavy trucks which have effects on the bridge. This study estimated the effect of contact area of design loads and real traffic vehicles through the finite element analysis considering the real loading conditions. The finite element analysis carried out 4 cases of loading patterns in the orthotropic steel deck bridge. Also, analysis estimated the influence of contact area of real truck loadings by the existence of diaphragm plate. The result of finite element analysis indicated that single tire loadings of real trucks occurred higher local stress than one of design loadings, and especially the deck plate got the most influence by the single tire loading. It was found that the diaphragm attachment at joint part of longitudinal ribs and transverse ribs had no effects on the improvement of structural performance against fatigue resistance in elastic analysis.

• Journal of Korean Society of Steel Construction
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• v.12 no.3 s.46
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• pp.239-250
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• 2000

This study investigates the mechanical behavior on trough rib to crossbeam joint in orthotropic steel plate decks, specially emphasizing on the effect of diaphragm inside trough rib on the fatigue behavior of slit by static and fatigue tests. In particular, the effects of diaphragm on in-plane stress and out-of-plane stress, stress concentration, propagation of fatigue cracks at the silt are studied. With the result of experiment and numerical analysis, we have estimated the fatigue strength using the nominal stress and hot-sport stress. The details with diaphragm have occurred about 50% stress reduction at trough rib part of trough rib to crossbeam joint than the detail without diaphragm, however, the lower parts of crossbeam have occurred much more stress. Initial crack size or slit have an considerable influence on the propagation of fatigue cracks due to V-notch. The fatigue strength category of the details without diaphragm has higher value than fatigue limit, whereas that of the details with diaphragm is estimated lower than fatigue limit.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.5
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• pp.68-77
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• 2014

In this study, polysulfide epoxy polymer concrete was chosen as an ultra thin bridge deck overlay, and the effect of polymer concrete pavement on the fatigue stress range of the orthotropic steel deck was analyzed through the comparative analysis with epoxy asphalt pavement and SFRC pavement. Abaqus was used to estimate the fatigue stress range, and signed von-mises stress was used to estimate fatigue stress range according to pavement materials and thickness, considering there were multi axis stresses which have longitudinal and lateral direction on the welded parts of the steel deck.

• Journal of Korean Society of Steel Construction
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• v.18 no.3
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• pp.289-299
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• 2006

Orthotropic steel decks are manufactured by welding thin plates therefore it is inevitable that there are abundant works of welding process. On connection of transverse rib web, crossing point of longitudinal rib, transverse rib and deck plate and cut-out parts of transverse rib are the significant position of stress concentration phenomenon because of out of plane and oil-caning deformation caused by longitudinal rib distortion with shear force and distortion. In order to reduce the stress concentration phenomenon and improving fatigue performance at the crosing point and cut-out, structural analysis was performed considering the existence of scalop at conection and diaphragm which have same plane with transverse rib placed inside of longitudinal rib. Result o f the analysis show that there are the largest efect of stres concentration reduction when diaphragms are installed without scallop at connection, therefore these detail can improve the fatigue performance of orthotropic steel decks.