• Title/Summary/Keyword: continuous-span bridge

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Seismic Risk Analysis of Reinforced Concrete Bridge Piers using Local Damage (국부손상을 이용한 RC교각의 지진위험도 분석)

  • Lee, Dae-Hyoung;Kim, Hyun-Jun;Park, Chang-Ky;Chung, Young-Soo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05a
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    • pp.194-197
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    • 2006
  • This study represents results of fragility curve development for 4-span continuous bridge. 2 type bridge model is chosen frame type and 2-roller 1-hinge type. To research the response of bridge under earthquake excitation, Monte Carlo simulation is performed to study nonlinear dynamic analysis. For nonlinear time history analysis a set of 150 synthetic time histories were generated. Fragility curves in this study are represented by lognormal distribution functions with two parameters and developed as a function of PGA. Five damage states were defined to express the condition of damage based on the actual experimental damage data of bridge column. As a result of this research, the value of damage probability corresponding to each damage state were determined and frame type bridge are favorable under seismic event.

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An improved pushover analysis procedure for multi-mode seismic performance evaluation of bridges : (1) Introduction to numerical model

  • Kwak, Hyo-Gyoung;Shin, Dong-Kyu
    • Structural Engineering and Mechanics
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    • v.33 no.2
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    • pp.215-238
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    • 2009
  • This paper introduces an improved modal pushover analysis (IMPA) which can effectively evaluate the seismic response of multi-span continuous bridge structures on the basis of modal pushover analysis (MPA). Differently from previous modal pushover analyses which cause the numerical unstability because of the occurrence of reversed relation between the pushover load and displacement, the proposed method eliminates this numerical instability and, in advance the coupling effects induced from the direct application of modal decomposition by introducing an identical stiffness ratio for each dynamic mode at the post-yielding stage together with an approximate elastic deformation. In addition to these two introductions, the use of an effective seismic load, calculated from the modal spatial force and applied as the distributed load, makes it possible to predict the dynamic responses of all bridge structures through a simpler analysis procedure than those in conventional modal pushover analyses. Finally, in order to establish validity and applicability of the proposed method, correlation studies between a rigorous nonlinear time history analysis and the proposed method were conducted for multi-span continuous bridges.

A Study on the Longitudinal Behavior of 2-Span Continuous Railway Bridge (2경간 연속 철도교의 종방향 거동에 관한 연구)

  • Im, Jung-Soon;Jo, Jae-Byung;Bahng, Yun-Suk
    • Journal of the Korean Society of Hazard Mitigation
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    • v.1 no.1 s.1
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    • pp.81-90
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    • 2001
  • This paper presents the results of the parametric study on the longitudinal behavior of 2-span continuous railway bridge. To perform the main objective of this paper, the effects of pier shaft stiffness, pier height, the size of pier foundation, and the bearing stiffness on the longitudinal behavior of the bridges are studied. Within the limits of this study, the research result has revealed that the variation of the fixed pier is more effective than that of the moved pier. In addition, the control of the hearing stiffness is much less expensive than that of any other parameters.

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Improved Method for Indeterminate forces of Two-span Steel-concrete Composite Girders (2경간 연속 강합성거더의 개선된 부정정력 계산 방법)

  • Ji, Gu Sam;Kim, Choong Eon;Shin, Dong Ki;Choi, Dong Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.2
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    • pp.423-431
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    • 2013
  • The k-factor method has been widely used in design of steel-concrete composite bridges to determine indeterminate stresses. The accuracy of k-factor method is examined by a comparative analysis with the equivalent load method in a continuous 2-span composite bridge. To improve the accuracy, the direction of creep stress has to be modified and the variety of section must be considered. This paper suggests j-factor method which can improve the accuracy of k-factor method with simple modification.

A parametric study of optimum tall piers for railway bridge viaducts

  • Martinez-Martin, Francisco J.;Gonzalez-Vidosa, Fernando;Hospitaler, Antonio;Yepes, Victor
    • Structural Engineering and Mechanics
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    • v.45 no.6
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    • pp.723-740
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    • 2013
  • This paper presents a parametric study of reinforced concrete bridge tall piers with hollow, rectangular sections. Such piers are typically used in railway construction of prestressed concrete viaducts. Twenty one different piers have been studied with seven column heights of 40, 50, 60, 70, 80, 90 and 100 m and three types of 10-span continuous viaducts, whose main span lengths are 40, 50 and 60 m. The piers studied are intermediate columns placed in the middle of the viaducts. The total number of optimization design variables varies from 139 for piers with column height of 40 m to 307 for piers with column height of 100 m. Further, the results presented are of much value for the preliminary design of the piers of prestressed concrete viaducts of high speed railway lines.

Static Aanlysis of Curved box Girder Bridge with Variable Cross Section by Transfer Matrix Method (전달행렬법에 의한 변단면 곡선 상자형 거더교의 정적해석)

  • Kim, Yong-Hee;Lee, Yoon-Young
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.7 no.4
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    • pp.109-120
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    • 2003
  • The state-of-art of curved box girder bridge with cross section design has advanced in various area. In these days, several analytical techniques for behaviors of curved box girder bridges cross section are available to engineers. The transfer matrix method is extensively used for the structural analysis because its merit in the theoretical background and applicability. The technique is attractive for implementation on a numerical solution by means of a computer program coded in Fortran language with a few elements. To demonstrate this fact, it gives good results which compare well with finite element method. Therefore, this paper proposed the static analysis method of curved box bridge with cross section by transfer matrix method based on pure-torsional theory and the optimal span ratio/variable cross section ratio of 3 span continuous curved box girder bridge.

Verification of bridges Design criteria for Continuous PSC Box Bridge of High Speed Railway Using Field Test (고속철도 연속 PSC Box 교량에 적용한 설계기준의 현장계측에 의한 검증)

  • Kang, Kee Dong
    • Journal of Korean Society of Steel Construction
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    • v.18 no.1
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    • pp.53-58
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    • 2006
  • The aim of this paper is to verify the dynamics stability of the continuous PSC Box bridges on the high-speed Kyoung-bu railway when a high-sped train runs through it. An experimental study was carried out to investigate the dynamic behaviors of the PSC Box railway bridge, which had ben designed based on dynamic design criteria. As a result, it was determined that PSC Box railway bridges possess enough dynamics stability for use by high-speed trains. According to the result of a field test (dynamics measuring analysis) that was conducted, an application of the natural frequency of train speed and the adjustment of the bridge's span length will allow one to come up with a more economical and suitable bridge design. Furthermore, it was found that the continuous control of the bridge's dynamic behavior and the bridge's maintena nce require the recording of data. The results of this study are very important in evaluating the structural stability of high-speed line bridges.

Evaluation of Stress Reduction of Continuous Welded Rail of Sliding Slab Track from Track-Bridge Interaction Analysis (궤도-교량 상호작용 해석에 의한 슬라이딩 슬래브 궤도의 장대레일 응력 저감 효과 분석)

  • Lee, Kyoung Chan;Jang, Seung Yup;Jung, Dong-Ki;Byun, Hyung-Kyoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.5
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    • pp.1179-1189
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    • 2015
  • Continuous welded rail on bridge structure experiences typically a large amount of additional longitudinal axial forces due to longitudinal track-bridge interaction under temperature and traction/braking load effect. In order to reduce the additional axial forces, special type of fastener, such as ZLR and RLR or rail expansion joint should be applied. Sliding slab track system is known to reduce the effect of track-bridge interaction by the application of a sliding layer between slab track and bridge structure. This study presents track-bridge interaction analysis results of the sliding slab track and compares them with conventional fixed slab track on bridges. The result shows that the sliding slab track can significantly reduce the additional axil forces of the continuously welded rail, and the difference is more significant for long and continuous span bridge.

A Study on the Applicability of SCP Girder to Continuous Bridges (SCP 합성거더의 연속교 적용에 관한 연구)

  • Kim, Jung Ho;Lee, Sang Yoon;Park, Kyung Hoon;Hwang, Yoon Koog;Yoo, Gun Woo
    • Journal of Korean Society of Steel Construction
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    • v.18 no.1
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    • pp.101-111
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    • 2006
  • The SCP girder, which compensates for the shortcomings of conventional girders through the effective composition of concrete, steel, and PS tendon, has recently been developed and applied on real bridges. Developed as a simple-support type, it may be applied on simple-support and continuous bridges by connecting the simple-support SCP girders to the interior supports. A continuous SCP girder, which has structural and cost advantages over the simple-support SCP girder, is proposed in this study. Likewise proposed herein is a new method of constructing a continuous SCP girder, using segments of the girder sequentially. A two-span, half-scale specimen was designed and constructed to verify the propriety of the continuous SCP girder bridge. A static load test was also carried out, using this specimen, to examine the behavior of the continuous SCP girder. Based on the results of the study, it is expected that the continuous bridge that uses the continuous SCP girder can guarantee the structural safety of the simple-support SCP girder.

Seismic Risk Assessment of Piers Using Fragility Analysis (취약도 분석을 통한 교각의 지진위험도 평가)

  • Lee, Dae-Hyoung;Kim, Hyun-Jun;Park, Chang-Kyu;Chung, Young-Soo
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.261-268
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    • 2006
  • This study represents results of fragility curve development for 3-span continuous bridge. To research the response of bridge under earthquake excitation, Monte Carlo simulation is performed to study nonlinear dynamic analysis. Because of limited number of real time histories from the Korean peninsula, a set of 150 synthetic time histories were generated. Fragility corves in this study are represented by lognormal distribution functions with two parameters and developed as a function of PGA. Five damage states were defined to express the condition of damage based on the actual experimental damage data of bridge column. As a result of this research, the value of damage probability corresponding to each damage state were determined. This approach may be used in constructing the fragility curves for all of bridge structure and, by extension, in constructing the seismic hazard map.

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