• Title/Summary/Keyword: crossbeams

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Design Improvements for Crossbeams and Stringers of Steel Box Girder Bridge (강박스거더교 가로보와 세로보 합리화 연구)

  • Gil, Heungbae;Kang, Sang Gyu;Cho, Jun Sang
    • Journal of Korean Society of Steel Construction
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    • v.20 no.1
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    • pp.1-8
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    • 2008
  • This research carried out to optimize crossbeams and stringers of steel box girder bridges, which are parts of floor system and support loading from the bridge deck. In the current design practice, the crossbeam is densely deployed with a spacing of 6 meters, and the stringer is placed between the crossbeams. The crossbeams and stringer are connected to the deck through slab anchors but the allowable stress of the compression flange is determined by the lateral-torsional buckling. To increase economic efficiency of the steel box girder bridges. the increased spacing of the crossbeam was studied. The study shows that the spacing can be increased up to 10 meters. However, higher strength steel plates are necessary. Shear studs rather than slab anchors are also recommended to prevent lateral-torsional buckling strength of the crossbeams and stringer.

Fatigue property analysis of U rib-to-crossbeam connections under heavy traffic vehicle load considering in-plane shear stress

  • Yang, Haibo;Qian, Hongliang;Wang, Ping
    • Steel and Composite Structures
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    • v.38 no.3
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    • pp.271-280
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    • 2021
  • In this study, the fatigue property of U rib-to-crossbeam connections in orthotropic steel bridge (OSB) crossbeams under heavy traffic vehicle load was investigated considering the effects of in-plane shear stress. The applicability of an improved structural stress (ISS) method was validated for the fatigue behavior analysis of nonwelded arc-shaped cutout regions in multiaxial stress states. Various types of fatigue testing specimens were compared for investigating the equivalent structural stress, fatigue crack initiation positions, and failure modes with the unified standards. Furthermore, the implications of OSB crossbeams and specified loading cases are discussed with respect to the improved method. The ISS method is proven to be applicable for analyzing the fatigue property of nonwelded arc-shaped cutout regions in OSB crossbeams. The used method is essential for gaining a reliable prediction of the most likely failure modes under a specific heavy traffic vehicle load. The evaluated results using the used method are proven to be accurate with a slighter standard deviation. We obtained the trend of equivalent structural stress in arc-shaped cutout regions and validated the crack initiation positions and propagation directions by comparing them with the fatigue testing results. The implications of crossbeam spans on fatigue property are less significant than the effects of crossbeams.

Analyzing the effect of crossbeams on the lateral distribution of bridges (가로보가 교랴의 횡분배에 미치는 영향 분석)

  • 한만엽;김현호
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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    • pp.315-319
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    • 2000
  • This study is to analyze the effect of the cross beam in bridge design. The analysis on the cross beam using FEM method is to find the best location and numbers of the cross beam in bridges. These analysis will allow economical design and construction in the field.

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Structural performance evaluation of bolted end-plate connections in a half-through railway inclined girder

  • Jung Hyun Kim;Chang Su Shim
    • Steel and Composite Structures
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    • v.49 no.5
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    • pp.473-486
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    • 2023
  • A through-railway bridge with an inclined girder has recently been applied to optimize the cross-section of a slender bridge structure in railway bridges. To achieve the additional cross-section optimization effect by the bolted end-plate connection, it is necessary to investigate the application of the bolted end-plate tension connection between the inclined girder and the crossbeam. This basic study was conducted on the application of the bolted end-plate moment connection of crossbeams to half-through girders with inclined webs. The combined behavior of vertical deflection and rotational behavior was observed due to the effect of the web inclination in the inclined girder where the steel crossbeam was connected to the girder by the bolted end-plate moment connection. Therefore, in the experiment, the deflection of the inclined girder was 1.77-2.93 times greater than that of the vertical girder but the lateral deflection of the inclined girder was 0.4 times less than that of the vertical girder. Moreover, the tensile stress of the upper bolts in the inclined girder with low crossbeams was clearly 0.81 times lower than that of the vertical girder. According to the results, the design formula for vertical girders does not reflect the influence of the web inclination. Therefore, this study proposed the design procedures for the inclined girder to apply the bolted end-plate moment connection of the crossbeam to the inclined girder by reflecting the design change factors according to the effect of the web inclination.

A Study on the Architectural Structure of Ancient Korean Wooden Buildings - Focused on the Analysis of the Architectural Elements of Stone Pagoads - (한국(韓國) 고대(古代) 대조건축(大造建築) 구조(構造)의 추정(推定)에 관(關)한 연구(硏究) -석탑(石塔)의 건축요소(建築要素) 분석(分析)을 중심(中心)으로-)

  • Park, Jae-pyoung;Lee, Jae-heun
    • Journal of the Korean Institute of Rural Architecture
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    • v.4 no.1
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    • pp.71-86
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    • 2002
  • This research aims to illustrate the structure of the ancient Korean wooden buildings by a comparative study of the historical resources such as stone remains, wall paintings historiographies and excavations. As stone pagodas are the most typical stone remains, I selected for analysis some stone pagodas which contain architectural elements and results of the study are as follows: 1) The number of stories and structural modes of the base stone part show the wooden architectural aspects: they have one or two stories and their base part is constructed in the mode of assembling rectangular stones. 2) The body of the pagoda contains such architectural elements as pillars, door and windows, crossbeams, balcony, bracket sets. 3) The roof of the stone pagoda contains such architectural elements as eaves, roofs and modes of stone assembling. The results inferred through this research could be of help for further comparative studies with the other secondary materials by providing basic knowledge for it.

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After-fracture behaviour of steel-concrete composite twin I-girder bridges: An experimental study

  • Lin, Weiwei
    • Steel and Composite Structures
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    • v.42 no.1
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    • pp.139-149
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    • 2022
  • To simplify the design and reduce the construction cost of traditional multi-girder structural systems, twin I-girder structures are widely used in many countries in recent years. Due to the concern on post-fracture redundancy, however, twin girder bridges are currently classified as fracture critical structures in AASHTO specifications for highway bridges. To investigate the after-fracture behavior of such structures, a composite steel and concrete twin girder specimen was built and an artificial fracture through the web and the bottom flange was created on one main girder. The static loading test was performed to investigate its mechanical performance after a severe fracture occurred on the main girder. Applied load and vertical displacement curves, and the applied load versus strain relationships at key sections were measured. To investigate the load distribution and transfer capacities between two steel girders, the normal strain development on crossbeams was also measured during the loading test. In addition, both shear and normal strains of studs were also measured in the loading test to explore the behavior of shear connectors in such bridges. The functions and structural performance of structural members and possible load transfer paths after main girder fractures in such bridges were also discussed. The test results indicate in this study that a typical twin I-girder can resist a general fracture on one of its two main girders. The presented results can provide references for post-fracture performance and optimization for the design of twin I-girder bridges and similar structures.

A Study on the characteristics of space design in the colonial period in Indonesia (인도네시아 식민시대의 공간양식 특성에 관한 연구)

  • Kang, Yu-Na;Oh, Hye-Kyung
    • Korean Institute of Interior Design Journal
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    • v.20 no.3
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    • pp.190-197
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    • 2011
  • The purpose of this study is to examine the characteristics of space design appearing in facade and interior composition factors of buildings in the colonial period in Indonesia. Research method is a field study, and subjects of the study is 14 buildings built in the colonial period located in Jakarta. The research result is as follows. First, Facade is divided into C type (colonial style), CT type (colonial style + traditional style), CA type (colonial style + art deco style), and CTA type (colonial style + traditional style + art deco style). Among them, CT type which shows both a colonial style and traditional style accounts for the most. As for Java traditional style mainly shows Joglo roof style and bratticing decoration on top of gates, and the colonial style presents both an Amsterdam canal housing style such as narrow Facade and unusual Gable, and a classical style such as pediment, entablature, and columns. Second, interior space is divided into C type (colonial style), CT type (colonial style + Indonesian traditional style), A type (art deco style), and CA type (colonial style + art deco style). Among them, CT type was also accounted for the most. Selected traditional style is a shape of bratticing decoration on top of gates and a shape of tenon of Joglo housing structure. Colonial style showed classical style such as exposed crossbeams, columns, and pilasters, and as for unique decoration, there are Ancona decoration and Delft tile decoration. On one hand, art deco style used typical art deco factors such as contrast of various materials and complementary color or golden color use as well as zigzag or vertical lines and geometric ornament by combining with colonial style or traditional style. It is expected that such research result will be a practical reference data when Korean construction companies or interior design companies advance Indonesia.

A Study on the Utilization of Perspective Representation in a Construction Space - centering on the tombs and mural paintings of Koguryo - (건축공간에서의 원근기법 이용에 관한 연구(1) - 고구려 무덤과 그 벽화를 중심으로 -)

  • Hong, Jae-Dong;Lim, Choong-Shin
    • Journal of architectural history
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    • v.6 no.3 s.13
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    • pp.129-143
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    • 1997
  • The perspective representation and its effect that appeared in the tombs and mural paintings of koguryo are summarized as follows: First, The inside structure of the tombs is likely to show the deepness effect, placing each function in the front and both sides centering around the mane pillars and creating the boundaries and the spaces that have various visibility between the inside and outside spaces of the structure just like a traditional Korean house shows. In addition, The deepness effect is emphasized by suggesting that the spaces are countinued with a storage attached behind the main house or by forming the level and deployment in a narrow space like the scene that a large array is looked out from the main house. Second, The deepness effect is expressed by making the form of ceiling turn to a vertical space of an ascending image, constructing it just as the lotus lamp ceiling of a wooden architecture or drawing it just like the imaginary heavenly world with the sun the moon and mythical fairies and animals spread in it. Thried, The perspective effect is disclosed by drawing the mural pictures in an equally set bird's-eye view without regard to the disfance proportion according to the conceptual visualization which is not a visual penetration, adopting the multiple view points and moving view points that are moving around as an important manner of seeing. Fourth, The deepness effect is emphasized through the scene of changing spaces when they are looked out far or looked into depending on a viewpoint of the daily life by forming the fromes of paintings that we made up with actual pillars, Du Gong, crossbeams or that are painted in most tombs. Fifth, The rich spatial senses are reflected by originating the characters of the three directions, level, deployment and ascending. An example which can support the conclusion of this study can be given here. that is, the construction ground plan of a dwelling house of a nobleman at the end of Koguryo as a remain which was excavated at Dongdae Ja in Jip An.

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A Comparative Study on the Transition of Purlin Coupling Method of Korean and Chinese Ancient Wooden Constructions (한중 목조건축 도리 결합방식 변천(變遷)에 관한 비교연구)

  • Cha, Ju-hwan
    • Korean Journal of Heritage: History & Science
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    • v.47 no.4
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    • pp.22-47
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    • 2014
  • This study was to understand the basic principles of the East Asian wooden structure system research and analysis. The Korea and China ancient architecture internal structure research that the combination of girders and crossbeams position. The ancient wooden structures of eastern Asian countries, Korea and China are not much different from each other in the principles of the wooden architecture structure, combining pillars, purlins and crossbeams. However, it seems that age-division, local-division, national-division differs in detail techniques. China ancient wooden structures combination of purlin and crossbeam, and So-seul Timber(Chinese name: Chashou叉手, Tuojiao 托脚) seems to show differences according to the age of the fulcrum position, detailed approach is also different according to various historical dynasty. Before in the 15th century, Purlin and Crossbeam are coupled to each other, but since the 15th century, seems to have developed a technique combined with each other Girder and Crossbeam and to prevent buckling of the Crossbeam cross-sectional area increased dramatically. For Tuojiao in China Tang-Wudai dynasty(A.D. 618~979), can see that saw the top position Girder and Tuojiao no direct coupling, can be seen as maintaining the safety of the material than the material of the inner wooden structures prevent buckling of the purlin. Korea ancient wooden structures of Goryeo dynasty(A.D. 918~1391), So-seul Timber(Chinese name Tuojiao) why do not to use the fashion? To use Purlin Lower backing material techniques to prevent buckling is a popular trend to stable can be thought of as a preferred way to maintain. I think that with universality beyond the local-division, national-division and the two countries since the 15th century of Korea and China ancient wooden structures detailed mechanism for the purlin buckling. In middle-late Chosen dynasty, The effect of Deotgeolyi- techniques and fleeting beams reduce the purlin buckling that reduces the load transmitted from purlin and crossbeam of how to reduce the load on the roof portion of the architecture fleeting beams used, which of craftsmanship of the Chosen Dynasty building can be referred to as another technique for preventing buckling purlin. This Korea and China ancient architecture purlin beam structure and material So-seul Timber study. Seems to be able to provide a basic research study to restore and designed the old wooden architectures.