• Title/Summary/Keyword: train-slab track-bridge interaction

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Random vibration analysis of train-slab track-bridge coupling system under earthquakes

  • Zeng, Zhi-Ping;He, Xian-Feng;Zhao, Yan-Gang;Yu, Zhi-Wu;Chen, Ling-Kun;Xu, Wen-Tao;Lou, Ping
    • Structural Engineering and Mechanics
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    • v.54 no.5
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    • pp.1017-1044
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    • 2015
  • This study aimed to investigate the random vibration characteristic of train-slab track-bridge interaction system subjected to both track irregularities and earthquakes by use of pseudo-excitation method (PEM). Each vehicle subsystem was modeled by multibody dynamics. A three-dimensional rail-slab- girder-pier finite element model was created to simulate slab track and bridge subsystem. The equations of motion for the entire system were established based on the constraint condition of no jump between wheel and rail. The random load vectors of equations of motion were formulated by transforming track irregularities and seismic accelerations into a series of deterministic pseudo-excitations according to their respective power spectral density (PSD) functions by means of PEM. The time-dependent PSDs of random vibration responses of the system were obtained by step-by-step integration method, and the corresponding extreme values were estimated based on the first-passage failure criterion. As a case study, an ICE3 high-speed train passing a fifteen-span simply supported girder bridge simultaneously excited by track irregularities and earthquakes is presented. The evaluated extreme values and the PSD characteristic of the random vibration responses of bridge and train are analyzed, and the influences of train speed and track irregularities (without earthquakes) on the random vibration characteristic of bridge and train are discussed.

Track-Structure Interaction Analysis of Fast Hardening Track on Railway Bridge Considering Effect of Anchor and Friction (앵커와 마찰의 영향을 고려한 교량상 급속경화궤도의 궤도-교량 상호작용해석)

  • Cho, Sang-Hyeon;Lee, Il-Wha;Chung, Won-Seok;Lee, Hee-Young;Lee, Kyoung-Chan
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.31 no.1
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    • pp.53-61
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    • 2018
  • Ballast track requires constant maintenance work due to progress of track irregularity. Fast Hardening Track(FHT) has been developed to reduce the maintenance effort done by injecting fast hardening mortar in aged ballast to convert slab track. For the application of FHT to a railway bridge, post-installed anchors should be placed at center of the track segment to fix it on bridge. This paper presents track-bridge interaction analysis results with FHT considering stiffness and strength of post-installed anchor, age of FHT concrete and friction between FHT and bridge deck surface. Based on the analysis results, this study suggests when is good to install the anchors and allow normal operation of passing train.

Analysis of Design Parameters for Earthwork/Bridge Transition Structure for Ultra-High Speed Running (초고속 주행시 교량/토공 접속부 보강방안의 설계변수 분석)

  • Lee, Il-Wha;Lee, Sung-Jin;Lee, Su-Hyung;Lee, Kang-Myung
    • Journal of the Korean Society for Railway
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    • v.18 no.2
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    • pp.117-126
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    • 2015
  • The development of railway roadbed for 600km/h train speed level is very difficult because unpredictable static and dynamic interaction occurs between the ultra-high speed train and the infrastructure. Especially, an earthwork-bridge transition zone is a section in which influential factors react, such as bearing capacity, compression, settlement, drainage, and track irregularity; these interactions can include complicated dynamic interaction. Therefore, if static and dynamic stability are secured in transition zones, it is possible to develop roadbeds for ultra-high speed railways. In the present paper, design parameters for transition reinforcement applied to present railway design criteria are analytically examined for ultra-high speed usage on a preferential basis. Design parameters are the presence of reinforcing materials, geometric shape, stiffness of materials, and so on. Analysis is focused on the deformation response of the track and running stability at ultra-high speed.

Safety Evaluation on Interaction between Track and Bridge in Continuous Welded Railway Bridge Considering Seismic Load (지진하중을 고려한 장대레일교량의 궤도-교량 상호작용에 대한 안전성 평가)

  • Shim, Yoon-Bo;Kim, Yun-Tae;Kim, Sang-Chel
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.2
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    • pp.40-48
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    • 2016
  • To observe the rail-slab interaction in continuous welded railway(CWR) bridge when earthquake occurs, additional axial rail stresses and relative longitudinal displacements between rail and bridge deck were calculated with input of various load combinations and 3 different types of seismic loads to an analytical model. As results of analysis, it can be found that standard response spectrum proposed by Korea Rail(KR) network authority for earthquake design showed less additional axial rail stresses than allowable levels, but greater relative longitudinal displacement between rail and bridge deck, which means that adjustment of relative longitudinal displacement within a standard level is much more difficult than axial train stress. Additionally, if a large-scaled earthquake as occurred at Kobe, Japan comes up, then both of additional axial rail stress and relative displacement in rail-bridge deck may exceed allowable levels, which indicates to make proper design guides against sudden earthquake occurrence.