• Title/Summary/Keyword: beam bridge

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Usage of Dynamic Vibration Absorbers for a Beam Subjected to Moving Forces and for a System Mounted on a Moving Base (이동하중을 받는 보와 가동 기초 위에 설치된 계에의 동흡진기의 이용)

  • Lee, Gun-Myung;Byun, Jai-Hyun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.14 no.6
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    • pp.27-34
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    • 2015
  • Dynamic vibration absorbers are widely used in machinery, buildings, and structures, including bridges. Two cases of their usage are considered in this paper. One is a simply supported beam subjected to either a moving force or a sequence of moving forces, which simulates a train-bridge interaction problem. The other is a case where a primary system is mounted on a base that is not grounded and is excited by an external force. The conditions that the dynamic vibration absorbers must meet in these cases are found and compared to those for usual cases where bases of primary systems are grounded.

Measurements of the Mechanical Properties of Electroplated Gold Microstructure (전해 도금된 마이크로 금 구조물의 기계적 특성 측정)

  • Baek, Chang-Wong;Kim, Yong-Kweon;Ahn, Yoo-Min
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.50 no.2
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    • pp.86-95
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    • 2001
  • Mechanical properties of electroplated gold microstructures were determined from the micromachined beam structures. Cantilever and bridge beam structures of different length were fabricated by electroplating-surface micromachining technique, which is specially designed to realize an anchor structure close to an ideal fixed-boundary condition. Fabricated beams were electrostatically excited and their resonance frequencies were measured by optical system composed of laser displacement meter with dynamic signal analyzer. Young's modulus and mean residual stress were calculated from the measured frequencies of microbeams. In addtion, stress gradient was measured using deformation of released cantilever beam structure.

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Analysis of PSC Beam Bridges Strengthened by External Post-Tensioning Method (외부 후긴장된 PSC보 교량의 해석방법)

  • 김광수;박선규;김형열;전찬기
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.04a
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    • pp.399-404
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    • 1999
  • An improved finite element modeling technique is proposed for the assessment of load carrying capacity partilly prestressed concrete beam bridges. Based on the finite element method of analysis, shell and frame elements are utilized to model the slab and beams of the superstructure, respectively. In the modeling of superstructure, the emphasis is placed on the use of rigid link between the middle surface of slab and mid-plane of beam. This paper also includes the comparision of three different equations that used in the calculation of effective moment of inertia for the partially prestressed concrete beams. Numerical analysis is performed for the unstrengthened and strengthened bridges. The obtained results are compared with those of load test for a prototype bridge. Agreement with the numerical solutions by using the proposed method and load test results is generally excellent.

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The Analysis of The Behavior of PSC Girder by Cross Beam (PSC 거더의 가로보 영향과 거동해석)

  • You, Jung-Doo;Park, Tae-Hyo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.169-170
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    • 2010
  • This paper mainly investigates the adequate number of cross beams at the IPSC(Incrementally PreStressed Concrete) girder bridge. The length of span was fixed to 50m and FE model was analyzed by using the ABAQUS program. The models for the numerical tests result in the cases whose number of cross beam are respectively 2, 3, 4, and 5. All of the results of proposed numerical tests satisfy the current specifications. Also, based on the results, we can determine the optimal number of cross beam for more economic design and improvement in constructability.

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Joint Shear Behavior Prediction for RC Beam-Column Connections

  • LaFave, James M.;Kim, Jae-Hong
    • International Journal of Concrete Structures and Materials
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    • v.5 no.1
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    • pp.57-64
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    • 2011
  • An extensive database has been constructed of reinforced concrete (RC) beam-column connection tests subjected to cyclic lateral loading. All cases within the database experienced joint shear failure, either in conjunction with or without yielding of longitudinal beam reinforcement. Using the experimental database, envelope curves of joint shear stress vs. joint shear strain behavior have been created by connecting key points such as cracking, yielding, and peak loading. Various prediction approaches for RC joint shear behavior are discussed using the constructed experimental database. RC joint shear strength and deformation models are first presented using the database in conjunction with a Bayesian parameter estimation method, and then a complete model applicable to the full range of RC joint shear behavior is suggested. An RC joint shear prediction model following a U.S. standard is next summarized and evaluated. Finally, a particular joint shear prediction model using basic joint shear resistance mechanisms is described and for the first time critically assessed.

Analysis of curved multicell box girder assemblages

  • Razaqpur, A. Ghani;Li, Hangang
    • Structural Engineering and Mechanics
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    • v.5 no.1
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    • pp.33-49
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    • 1997
  • A method of analysis is proposed for curved multicell box girder grillages. The method can be used to analyze box girder grillages comprising straight and/or curved segments. Each segment can be modelled by a number of beam elements. Each element has three nodes and the nodal degrees of freedom (DOF) consist of the six DOF for a conventional beam plus DOF to account for torsional warping, distortion, distortional warping, and shear lag. This element is an extension of a straight element that was developed earlier. For a more realistic analysis of the intersection regions of non-colinear box girder segments, the concept of a rigid connector is introduced, and the compatibility requirements between adjoining elements in those regions are discussed. The results of the analysis showed good agreement with the shell finite element results, but the proposed method of analysis needs a fraction of the time and effort compared to the shell finite element analysis.

Studies of Dapped Ended Beams with Disturbed Regions Containing T-headed bars and Steel fibers (헤디드 바와 강섬유로 보강한 Dapped Ended Beam의 구조 실험)

  • Choi Jin Hyouk;Lee Chang Hoon;Lee Joo Ha;Yoon Young Soo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05a
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    • pp.39-42
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    • 2005
  • This test program is to investigate the benefits of using headed bars to replace conventional stirrups and using steel fibers to reinforce in the disturbed regions in the dapped ended beam, This distribution of reinforcement was selected for aspects associated with the portion of beam section in bridge structures. The beams containing T-headed bars have a superior performance such as improved ductility, larger energy adsorption and enhanced post-peak load carrying capability. The capacity of DEB with steel fibers also show increase of ductility, shear strength, and crack.

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A Study on the Analysis of Overload of a Two-Span Continuous Bridige (2경간 연속교의 과재하중 해석방법에 관한 연구)

  • 한상철
    • Journal of the Korean Society of Safety
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    • v.8 no.1
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    • pp.47-53
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    • 1993
  • Residual Deformation Analysis(RDA) is a new method for ratings of the continuous bridges. The RDA makes it possible to expand the inelastic steel girder bridge design method set forth in the American Association of State Highway Officals'(AASHTO) Guide Specifications for Alternate Load Factor Design Procedures for Steel Beam Bridges Using Braced Compact Sections(1986) into an inelastic rating method. It is a method to assess the residual moments and deformations that are set up in a beam that has been loaded into the post-elastic range This method combines classical elastic conjugate beam theory with linear moment-rotation relationships for midspan inelastic positive moment. The limit state is inelastic serviceability limit. which is defined as the ratio of the span to midspan inelastic deflection(C=L/D).

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A Comparative Study of Landscape Characteristics on Bridges in Palaces of Korea and China - Focusing on the Chosun Dynasty and Ming and Qing Dynasties - (한국과 중국의 궁궐 내 교량에 관한 경관특성 비교 연구 - 조선시대와 명·청시대를 중심으로 -)

  • Zhang, Fu-Chen;Lee, Ai-Ran
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.37 no.3
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    • pp.1-12
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    • 2019
  • A bridge is a structure constructed on water or in the air for convenient passage. Compared to other buildings, the building materials and structures of bridge required unique functions to cross the space. It depends on the productivity of the building, the level of science and technology, and the ecological environment of the building site. Also, it has important relationship with functions such as politics, military, economy, and life. Most of the academic research on bridges is focused on research in the field of bridge-building technology, so the study on the landscape aesthetics and history of bridges is lacking. Against this backdrop, the study will be valuable as a accumulation of both countries' understanding of bridge types, history and culture, as well as technical and aesthetic data, by analyzing the bridges located within the palaces of Korea and China. The research method is to analyze the bridge through field survey and literature analysis.. First, the bridges of royal palace of Korea and China are to be classified quantitatively as physical shapes, landscapes, and decorations by comparing the materials, forms, landscapes, and decorative culture of bridges. Second, characteristics, common points, and differences are extracted by classifying bridges of both countries. Also, the results are discussed based on the physical environment or cultural background. This would be worth cross-referencing in the building technology and aesthetics of the two countries. For the first important characteristics of result, main materials of Korean and Chinese palaces are stone. However, the bridge in China's royal palaces is also focused on wood. Second, in terms of form, the bridges in the royal gardens of Korea and China are all based on the beam bridge. However, the specific form, ratio, style of the beam bridge, and airspace of arched bridge are very different. Third, most of the connection methods are focused on the over bridge. It values the convergence with the surrounding landscape. Due to the difference in the area and location of water, the bridge in the Korean palace is more focused on the convergence of the surrounding buildings and plants, while the bridge in the Chinese palace is more concerned about the harmony of hydration. Fourth, the decoration places importance on the artistry and aesthetics of both the bridges in Korea and China. There is a difference in style in the same type of decoration due to culture.

An Experimental Study on the Structural Behavior of Steel-Concrete Composite Rahmen Bridge with Hinged End Supports (하단힌지 강합성 라멘교의 구조적 거동에 대한 실험적 연구)

  • Choi, Jin Woo;Jang, Min Jun;Cheon, Jin Uk;Yoon, Soon Jong
    • Journal of Korean Society of Steel Construction
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    • v.27 no.2
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    • pp.195-205
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    • 2015
  • The rahmen bridge is well known common type of bridge in which all members are connected rigidly. The rahmen bridge is built for several situations because it has many advantages such as no need of bridge bearing system, easy of maintenance, reduction of the cross-sectional area of superstructure, and relatively low construction cost compared with other bridge types. Recently, to lengthen the span of rahmen bridge system, steel-concrete composite beam is used for superstructure of rahmen bridge instead of normal concrete girder with slab. However, member forces are increased because of extension of span length of superstructure and substructure is designed and constructed inefficiently when steel-concrete composite rahmen bridge is designed. In this study, new-type steel-concrete composite bridge is suggested. New-type steel-concrete composite rahmen bridge is adopted hinge connection between abutment and foundation for the reduction of the bending momemt at the foundation. In this study, we present the results of experiment conducted to estimate the load carrying capacity of new-type steel-concrete composite rahmen bridge and the structural characteristics of hinge connection.