• Title, Summary, Keyword: 지간장

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Resonance Phenomenon according to the relationship between Span Length of the Bridge and Effective Beating Interval of High-Speed Train (교량의 지간장과 고속전철하중 유효타격간격 사이의 관계에 따른 공진현상)

  • 김성일;곽종원;장승필
    • Journal of the Earthquake Engineering Society of Korea
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    • v.3 no.2
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    • pp.67-76
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    • 1999
  • Resonance of the bridge can be occurred with the coincidence between a natural frequency of the bridge and a crossing frequency of moving loads which is determined from the speed and effective beating interval of the vehicle. In case of the railway bridge, the effective beating interval of the vehicle is fixed under the passage of specific trains. In the present study, resonance and cancellation of the bridge subjected to moving high-speed train are analyzed with the variations of span length. A steel-concrete composite railway bridge is idealized by the combinations of plate elements and space frame elements. High-speed train is idealized with moving constant forces and a 3-dimensional full modelling. From analyzing dynamic responses of D.M.F of vertical displacement, maximum vertical acceleration of the slab, and end rotation according to the variations of span length of the bridge, design criteria of span length of the bridge which satisfies dynamic safety is discussed.

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Development of Short-span Precast Concrete Panels for Railway Bridge (철도교용 단지간 프리캐스트 콘크리트패널의 개발)

  • Seol, Dae-Ho;Lee, Kyoung-Chan;Kim, Ki-Hyun;Youn, Seok-Goo
    • Journal of the Korea Concrete Institute
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    • v.28 no.5
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    • pp.545-553
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    • 2016
  • This paper presents experimental static test results of the precast concrete panels developed for short-span concrete bridge deck form. Different from LB-DECK, concrete rib attached to the bottom surface of concrete panel, and Top-bar is not used at the top surface of concrete panel. Number of concrete ribs and cross-section details of concrete rib are determined from the analytical results of parametric study considering the span length and the thickness of concrete bridge decks. Shear rebars are installed at the top surface of concrete panel for composite action between precast concrete panel and cast-in-place concrete. In order to evaluate the safety and the serviceability of the developed short-span concrete panel subjected to design load, static load test is conducted. Three test panels with span length of 1.6m are fabricated, and during the load test displacements, strains and cracks of test panels are measured and final failure modes are investigated. Serviceability of the test panels is evaluated based on the results of displacements, cracking load, and crack width at the design load level. Safety is also evaluated based on the comparison of the ultimate strength and the factored design load of test panels. Based on the test results, it is confirmed the short-span precast concrete panel satisfies the serviceability and safety regulated in design codes. In addition, the range of span length of concrete bridge decks for the short-span concrete panel is discussed.

Development of Prestressed Steel Frame Overpass using Temporary Piers (가 지지점을 이용한 프리스트레스된 강재 라멘식 보도육교의 개발)

  • Kong, Byung Seung;Hwang, Won Sup;Park, Young Je
    • Journal of Korean Society of Steel Construction
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    • v.10 no.4
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    • pp.565-575
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    • 1998
  • This study presents overall process for designing and constructing a prestressed frame overpass using temporary piers. For the purpose of automating the design process, this study presents a computer program. According to the effective span(20m, 25m, 30m, 35m, 40m, 45m), this study performed parametric analysis and eventually presented appropriate cross section and compared this cross section with that of the existing simple steel overpass in girder height and quantify of the steel. $26{\sim}48%$ for gilder height and $25{\sim}34%$ for quantify of the steel are reduced as the result of study for span length $20{\sim}45m$. As long as the span length. the reduction rate was large.

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Dynamic Characteristics of Simply Supported Single Span Bridges for KTX and HEMU using Design Diagram (설계다이어그램을 이용한 KTX와 HEMU 차량 주행시 단경간 단순지지 교량의 동특성 분석)

  • Cho, Jeong-Rae;Cho, Keunhee;Kwark, Jong-Won;Kim, Young Jin
    • Journal of the Korean Society for Railway
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    • v.15 no.5
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    • pp.498-507
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    • 2012
  • This paper presents the ERRI design diagrams of KTX and HEMU applicable to simply supported single span bridges, and analyzes the dynamic characteristics and design considerations of the bridges under KTX and HEMU using the diagrams. The design diagrams of KTX and HEMU are calculated for the bridges with 25m, 30m, 35m and 40m span lengths, which are widely used for simple bridge in Korea. From the design diagrams, the dynamic characteristics of the bridges with the selected span lengths are analyzed. In addition, the design consideration is discussed to satisfy the design requirement of acceleration. It is desirable for the bridge with 25m span length to avoid resonance both for KTX and HEMU. Since larger responses are expected for HEMU in the bridge with 30m span length, and for KTX in the bridge with 35m and 40m span length, the bridges should be planned to have enough mass satifying acceleration requirement at resonance, or to avoid the resonance.

Concrete Shear Strength of FRP Reinforced Concrete Beam (FRP 보강근을 사용한 콘크리트 보의 콘크리트 전단강도)

  • Cho, Jae Min;Jang, Hee Suk;Kim, Myung Sik;Kim, Chung Ho
    • Journal of The Korean Society of Civil Engineers
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    • v.29 no.3A
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    • pp.259-266
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    • 2009
  • This study is to develop equations that consider the elastic modulus ratio of FRP bar and steel reinforcement, shear span to depth ratio, and flexural reinforcement ratio of FRP bar, to determine concrete shear strength of FRP reinforced concrete beams without shear reinforcement. As experimental parameters, 2 types of FRP bar, 3 types of shear span to depth ratio, and 3 types of flexural reinforcement were used. Experimental results for two of shear span to depth ratio were quoted from previous study to evaluate effect of shear span to depth ratio in more detail. Shear strength correction factors needed for evaluating concrete shear strength were proposed from regression analysis using above experimental results. Equations suggested from this study and other codes were examined and compared with 31 experimental results available in the literature. From this comparison, it could be known that the equation suggested from this study gives the most approaching result to experimental results.

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경부 고속철도 교량 건설공범 - 8-2공구를 중심으로 -

  • 황낙연;김창환
    • Journal of the Korean Society for Railway
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    • v.4 no.2
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    • pp.19-28
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    • 2001
  • 고속철도에서는 고속주행으로 인한 탈선을 방지하기 위하여 연직 또는 평면선형에 대하여 매우 엄격히 제한하고 있다. 종방향 경사는 2.5% 이하, 평면곡선반경에 대하여는 7,000 m 이상으로 규정하고 있으므로, 도로는 물론 일반철도에 비하여 교량구조물 발생은 더욱 증가된다. 한편 고속철도 교량은 구조물의 안전성 뿐만 마니라 승차감을 위하여 동적거동에 대하여 엄격히 제한된다. 또한 교량과 레일의 상호작용 등에 따라 무한장 개념의 레일에 악영향을 피하기 위해 교량의 종방향 변위도 제한되기 때문에 지간 장이 짧고 상판 구조물은 큰 강성을 갖게 된다. (중략)

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Analysis of Two-Span Structures Constructed by Incremental Launching Method (ILM 공법에 의해 시공된 2경간 구조물의 해석)

  • Kim, Sung Hoon;Kim, Bu Kyu;Choi, Jun Hyeok
    • Journal of Korean Society of Steel Construction
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    • v.28 no.1
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    • pp.35-42
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    • 2016
  • This paper presents the structural analysis of two-span structures constructed by incremental launching method to traverse the existing facilities. The structure with a relatively short launching span can not be secure the structural stability caused by excessive deflection and overturning prior to reaching the maximum strength, because the length of the other span is different or the rear structure is not continuous. In order to estimate the stability of the construction stages of deflection and the overturning, the structural analysis was carried out. The parameters of the analysis is launching span ratio of the launching nose and the upper structure, weight ratio and so on. From the analysis result, the effects of parameters were investigated and a deflection formula of the launching nose and the condition of the overturning of structure were proposed.

A Study on Standard Section of Simplified Composite Steel I-Beam Bridge Based on KRTA Design Specifications (도로교 설계 기준을 적용한 초간편 H-형강 교량 최적 단면 제안)

  • Kim, Jae-Heung;Park, Jong-Sup;Lee, Son-Ho
    • Proceedings of the KAIS Fall Conference
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    • pp.132-134
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    • 2008
  • 본 연구에서는 도로교 설계 기준 바탕으로 H-형강을 사용하여 20~30m 사이의 지간장을 가진 중 소규모 교량에 적용이 가능한 초간편 교량에 사용될 최적 H-형강 선정에 대한 설계 방법을 제시하고 있다. 본 연구는 구조적 안정성을 확보하고, 가로보를 생략한 단순구조를 갖으며, 도로교 설계 기준을 적용한 초간편 H-형강 교량의 경제적이고 합리적인 설계의 방법을 제공 하고 있다.

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A Study of Optimum Section of PSC Girder Railway Bridge according to Variation of Span Length (지간장 변화에 따른 프리스트레스트 콘크리트 거더 철도교의 최적단면에 관한 연구)

  • Cho Sun-Kyu;Kim Su-Hyun;Lee Jong-Min;Lee Tae-Gyun
    • Proceedings of the KSR Conference
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    • pp.1209-1214
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    • 2005
  • Prestressed concrete girder(PSC girder) bridges have been used widely at the railway as well as highway because they are great in the functional and economical efficiency. Also they have the advantage of convenience of design and construction. Generally, the PSC girder railway bridges with span length 25m are adopted in the country and it could be easily verified that the section of PSC girder using railway bridge is excessive design, which has much redundancy against design loads. Thus, in this paper the optimum design for PSC girder railway bridge with span length 30m is performed. And from the results of analysis it is suggested to denote the optimum section which satisfies the structural safety and economical efficiency all together.

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Study on the Impact Factors and the Fundamental Frequency Using Statistics of Dynamic Load Test of Railway Bridges. (철도교의 동적 재하시험 통계자료를 활용한 고유진동수와 충격계수 연구)

  • Jung, Hyun-Jun;Kim, Gyu-Seon;Lee, Sang-Cheol;Ju, Min-Kwan
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.61-62
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    • 2010
  • This paper provides an analysis using statistical method on the basis of database (DB) of bridge inspection reports performed by KISTEC from 1995 to 2007. Measured impact factors of total 36 railway bridges were classified by the span length, type of bridges and natural frequency. The fundamental frequency and the impact factors of inspected bridge are compared with formulas specified in both domestic and foreign railway bridge design codes.

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