• Title/Summary/Keyword: Bridge structure

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A Study on Applying Information Framework for BIM Based WBS -Focusing on Civil Construction- (BIM기반의 WBS 구축을 위한 정보프레임워크 도입방안 연구 -토목사업의 적용을 중심으로-)

  • Nam, Jeong-Yong;Jo, Chan-Won;Park, So-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.11
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    • pp.770-777
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    • 2017
  • Building information modeling (BIM) has been receiving attention as an integrated information model instead of CAD since the 2000s. BIM technology was first used in the architectural field and was later introduced to the civil engineering field. However, the government announced a plan for the application of BIM to 20% of all SOC projects from 2020, so the adoption of BIM technology is expected to accelerate. In order to successfully adopt BIM, a systematic structure should be supported for integrated design information and implementation technology. Also, it is important to establish the relationship between information systems because many complicated factors are intertwined in the construction industry. In this study, we propose a framework for constructing integrated information through identifying the information relations for introducing BIM in the civil engineering industry. We applied this framework to a bridge project to confirm its effectiveness. This study can be applied to the integrated management of the construction process and costs by introduction of a work breakdown structure (WBS) to BIM. In addition, this study is expected to contribute to the adoption of BIM in the civil engineering field through the proposal of information system standardization in this field.

An Experimental Study on Joint Structures of Composite Truss Bridges (복합 트러스 교량의 연결구조에 대한 실험적 연구)

  • Shim, Chang Su;Park, Jae Sik;Kim, Kwang Soo
    • Journal of Korean Society of Steel Construction
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    • v.19 no.3
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    • pp.303-312
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    • 2007
  • Steel box girder bridges are being commonly designed for medium-span bridges of span length. Composite truss bridges with steel diagonals instead of concrete webs can be an excellent design alternative, because it can reduce the dead weight of superstructures. One of the key issues in the design of composite truss bridges is the joint structureconnecting the diagonal steel members with the upper and lower concrete slabs. Because the connection has to carry concentrated combined loads and the design provisions for the joint are not clear, it is necessary to investigate the load transfer mechanism and the design methods for each limit state. There are various connection details according to the types of diagonal members. In this paper, the joint structure with group stud connectors welded on a gusset plate is used. Push-out tests for the group stud connectors of were performed. The test results showed that the current design codes on the ultimate strength ofthe stud connection can be used when the required minimum spacing of stud connectors is satisfied. Flexure-shear tests were conducted to verify the applicability of the design provisions for combined load effects to the strength of joint structures. To increase the pullout strength of the connection, bent studs were proposed and utilized for the edge studs in the group arrangement of the joint. The results showed that the details of the joint structure were enhanced. Thereafter, design guidelines were proposed.

Evaluation of Isolation Mechanism of Teflon or Steel Slag-Type Seismic Foundation Isolation Systems (테프론 또는 제강슬래그를 활용한 기초형 지진격리장치의 면진 메카니즘 평가)

  • Son, Su Won;Kang, In-Gu;Pouyan, Bagheri;Kim, Jin Man
    • Journal of the Korean Geotechnical Society
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    • v.34 no.1
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    • pp.5-16
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    • 2018
  • In this study, seismic performance of geotechnical seismic isolation system capable of primary seismic isolation in the ground was evaluated. 1-G shaking table test was used to assess the performance of Teflon or steel slag as geotechnical seismic isolation systems installed beneath superstructure foundation. Response acceleration and response spectra were analyzed considering different input motions. The results were compared with those of fixed foundation structure without seismic isolation system. The steel slag-type seismic isolation system showed significant reduction in acceleration. The teflon-type seismic isolation system did not show significant effects on acceleration reduction in low-to-moderate seismicity condition, but it did show better effects in case of strong seismic condition. As input motion was transferred to the upper mass, the response spectrum of the fixed foundation structure was amplified in the short period range. In contrast, the response spectrum of the structure with seismic isolation using teflon or steel slag amplified in the long period range. It is found that the change of periodicity and the friction characteristics between isolation materials and foundations affected acceleration reduction.

Seismic Fragility of Bridge Considering Foundation and Soil Structure Interaction (교량기초 종류 및 지반-구조물 상호작용을 고려한 지진취약도 분석)

  • Kim, Sun-Jae;An, Hyo-Joon;Song, Ki-il
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.6
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    • pp.129-137
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    • 2020
  • In performing the structural analysis, the foundation is considered to be a fixed end as a plastic hinge model. In this study, the displacements of the foundation, pier, and shoe were compared when the foundation modeled as a fixed end, a shallow foundation constructed on bedrock of 2m depth, and a pile foundation constructed in the 10m to 20m depth of bedrock. The shear force was also compared, and the probability of damage was calculated and compared for the critical condition. When calculated as a fixed end, the displacement of the foundation converged to 0mm, but the shallow foundation built on the bedrock with a depth of 2m caused relatively displacement, and the pile foundation constructed to contact the bedrock with a depth of 18m caused a larger displacement. In addition, it was analyzed that the displacement of the foundation, which is the lower structure, affects the displacement of the super structure, but the difference in shear force applied to the foundation was insignificant in the three cases. There was no difference between the shallow foundation and the pile foundation in the influence on the displacement of the top of the pier, but there was a big difference from the analysis assuming as a fixed end.

FTIR spectroscopy of the two-photon product of sensory rhodopsin I

  • Sasaki, Jun;Kannaka, Masato;Kandori, Hideki;Tokunaga, Fumio
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.534-536
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    • 2002
  • A halophilic archaeon, Halobacterium salinarum, exhibits phototactic behaviors, by which the organism is guided to red-orange light and evades shorter wavelengths of light. The phototaxis is mediated by two retinal proteins, sensory rhodopsin I and II (SRI and SRII), whose structures are analogous to the cognate protein bacteriorhodopsin, a light-driven proton pump. SRI mediates both attractant and repellent swimming behaviors to orange light and near- UV light, respectively. The two different signaling through the single photoreceptor have been ascribed to the presence of two active structures of SRI (S$\_$373/ and P$\_$520), which are produced upon orange light illumination of SRI and upon subsequent near-UV illumination of S$\_$373/, respectively. In the present study, we have measured the difference FTIR spectra of S$\_$373/ and P$\_$520/ states. In P$\_$520/, the isomeric structure of the chromophore is assignable to all-trans, and the Schiff base of the chromophore is protonated with concomitant deprotonation of Asp76, a combination which allows for the formation of a salt bridge between them. It was suggested that the way of interaction between the Schiff base and the counterion, which is different among SRI$\_$587/, S$\_$373/ and P$\_$520/ and which has been shown to drive the conformational changes in the cognate protein, bacteriorhodopsin, is the key to controlling conformational changes for the attractant and the repellent signaling by SRI.

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A Study on the Structural Behavior and Safety Evaluation based on Field Measurement Value of Launching Truss (런칭 트러스의 안전성 평가 및 실측치에 기초한 구조거동에 관한 연구)

  • Park, Young Hoon;Lee, Seung Yong;Jeon, Jun Chang;Chang, Dong Il
    • Journal of Korean Society of Steel Construction
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    • v.10 no.3 s.36
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    • pp.383-391
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    • 1998
  • Launching truss used for constructing the precast segmental concrete bridge has upper chord, lower chord and diagonal members. And the pin is used for connecting these members. From the field loading test carried out for investigating the actual behavior of launching truss, the great difference is analyzed between measured stress and calculated stress. Based on measured value, the structural analysis are carried out about assumed abnormal behavior of connection part. From the results of analysis, it is analyzed that the abnormal behavior of connection part greatly affect the structural behavior of launching truss. In addition, from the investigation of safety of launching truss, it is evaluated that the launching truss has enough safety with normal behavior of connection part.

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Dynamic Analysis of MABB(Multiple Arches Bowstring Bridge) and Single Arch Subjected to Moving Loads (이동하중을 받는 다중아치와 일반아치의 동적거동 분석)

  • Yhim, Sung Soon;Kim, Dong Yong;Son, Suk Ho;Kong, Min Sik
    • Journal of Korean Society of Steel Construction
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    • v.17 no.5 s.78
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    • pp.537-547
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    • 2005
  • MABB(Editor's note: Please spell out "MABB" upon first mention)is a new structural type of arch that connects arch ribs and stiffened girders with two internal arches. In this study, the static and dynamic behavior of MABB were analyzed in comparison with those of conventional arches for the investigation of the structural effect of MABB on moving loads. For the purpose of surveying the effect of internal arches on the dynamic behavior of structure, natural frequency and natural vibration mode were investigated and the static and dynamic behavior were analyzed by the method of idealizing train loads as traveling loads consisting of a group of concentrated loads. From the results, the following conclusions were known. First, it is concluded that with MABB, decreasing the section of stiffened girders is possible as compared with conventional arches because the increase of stiffness by internal arches is larger than that of the mass of internal arches. Second, MABB has the advantage of assurance of stability of dynamic behavior because the dynamic behavior of MABB on moving loads is usually investigated in a more stable way than that of conventional arches.

Structural Design and Evaluation of Six-component Wheel Dynamometer (6축 휠 동력계의 구조설계 및 평가)

  • Kim, Man Gee;Joo, Jin Won
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.1
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    • pp.53-63
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    • 2016
  • Wheel dynamometers are used to measure dynamic load that is conveyed from the road to a vehicle while driving. In this paper, two types of six-component wheel dynamometers utilizing shear deformation and bending deformation were designed and evaluated. Prior to designing the shear and bending type wheel dynamometers, the shear and bending deformation behaviors of the basic structure of the wheel dynamometer itself were analyzed using finite element analysis. Strain analysis was performed repeatedly in order to obtain a similar output sensing strain for each load component. The design was modified with a bridge circuit in order to minimize coupling strain. The results indicated that the shear type dynamometer was expected to obtain stable characteristics due to uniform strain distribution while the bending type dynamometer was expected to obtain high-quality sensitivity performance due to consistent output sensitivity.

A Study of Wildlife Roadkill in Joongang Highway (우리나라 야생동물의 도로치사에 관한 연구 -중앙고속도로의 동물치사 사례를 중심으로-)

  • Lee, Sang-Don;Cho, H.S.;Kim, J.G.
    • Journal of Environmental Impact Assessment
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    • v.13 no.1
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    • pp.21-31
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    • 2004
  • Construction of highway would influence wildlife habitat being fragmented and deteriorated. It is inevitable to observe the death of animals that are killed by vehicles. Nonetheless the cause and status of animal roadkill have not been studied, and this study first attempted to analyze the roadkill in major highway in Korea. We collected 860 individuals of dead animals in Joongang Highway during 1996-2003. Among them Korean hare(Lepus sinensis) was totaled in 165 individuals(19.2%) with the highest figure; Korean racoon dog(Nyctereutes procyonoides) was 146(17.0%); Korean squirrel(Sciurus vulgaris) 56(6.5%); Korean roe deer(Capreolus capreolus) 26(3.0%). Domestic animals was totaled in 232 individuals(27.0%); domestic dog(Canis familiairis) 25, and domestic cat(Catus felis) 207. This study also categorized habitat as mountain-mountain, mountain-plain, mountain-river, plain-plain, plain-river, river-river in each side of the road. Habitat of mountain-plain was the heightest with 296(38.9%) individuals followed by mountain-mountain with 263(34.6%). This indicates that wild animals associated with mountain habitat was most influenced by the construction of roads. This study implied that we should mitigate the roadkill by designing artificial construction such as eco-bridge, fences along the sideway, and boxes under the highway, underdrain structure, etc. The monitoring and cause of habitat fragmentation with GIS approach should be followed to reduce the roadkill.

Evaluation of P-M Interaction Curve for Circular Concrete-Filled Tube (CFT) Column (원형 콘크리트 충전 강관(CFT) 기둥의 P-M 상관 곡선 평가)

  • Moon, Jiho;Park, Keum-Sung;Lee, Hak-Eun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.2
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    • pp.355-365
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    • 2014
  • Concrete-filled tubes (CFTs) have been used in civil engineering practices as a column of buildings and a bridge pier. CFTs have several advantages over the conventional reinforced concrete columns, such as rapid construction, enhanced buckling resistance, and inherited confinement effect. However, CFT component have not been widely used in civil engineering practice, since the design provisions among codes significantly vary each other. It leads to conservative design of CFT component. In this study, the design provisions of AISC and EC4 for CFT component were examined, based on the extensive test results conducted by previous researchers and finite element analysis results obtained in this study. Especially, the focus was made on the validation of P-M interaction curves proposed by AISC and EC4. From the results, it was found that the current design codes considerably underestimated the strength of CFT component under general combined axial load and bending. Finally, the modified P-M interaction curve was proposed and successfully verified.