• Title, Summary, Keyword: 접속슬래브

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Experimental Study on the Structural Behavior of Typical Bar Connections of Approach Slab in the Integral Abutment Bridge (일체식교량의 접속슬래브 연결철근 형상에 따른 연결부 구조거동에 대한 실험연구)

  • You, Sung-Kun;Kim, Na-Yeon;Kim, Ho-Seop;Kim, Hyun-Gi;Kim, Young-Ho
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.5 no.4
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    • pp.24-35
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    • 2014
  • An experimental study on the structural behavior of connection types between approach slab and integral abutment has been done for three typical bar connections. Typical hinge style reinforcing bar detail for its connection is preferred in order to accommodate rotation of the approach slab among engineers. However, the straight horizontal bars can be used as connection detail accomodate structural capacity. Total six specimens with three types of rebar detail are tested for direct tensile and bending load. The characteristic structural behaviors are carefully monitored and all the strain gauge data obtained are analyzed. It is shown that the structural performance of all the specimens well exceed its design allowance. Several design suggestions are given based on careful reviews on the experiment.

Evaluation of Dynamic Stability of Precast Floating Slab Track with Vehicle-Track Interaction Analysis (차량-궤도 상호작용 해석을 통한 사전 제작형 플로팅 슬래브 궤도의 동적 안정성 검토)

  • Jang, Dongdoo;Kim, Jin-Ho;Kwon, Se-Gon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.3
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    • pp.562-568
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    • 2017
  • A precast floating slab track with a 5m slab panel and installed with isolators is proposed to solve the noise and vibration problem at existing elevated railway stations. Thus, the construction can be carried out rapidly without interrupting the train operation. However, dynamic instability problems may be caused by repeated discontinuities in track due to the short slab panel length and excessive rail displacement due to the inherent operation mechanism of a floating system in reducing the vibration. Furthermore, the difference of the supporting stiffness at the transition between the floating track and ballast track may raise problems. In this study, the assessment factors to evaluate the dynamic stability of the precast floating slab track are presented and assessed with the vehicle-track interaction analysis. Through the analysis, all values relevant to the stability at the floating track section are found to be acceptable, and the slab panels at the transition section are designed to satisfy the stability.

A Study on Settlement according to Height and Ground stiffness on the MSEW on the IPM Bridge (토압분리형 교량의 보강토옹벽의 높이와 기초지반 강성에 따른 침하량 검토)

  • Park, Min-Cheol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.5
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    • pp.399-409
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    • 2018
  • The mechanically stabilized earth wall (MSEW) of the IPM bridge is an important structure that constitutes the bridge, and supports the horizontal earth pressure and approach slab. Therefore, it is necessary to carefully analyze the settlement of MSEW of the IPM bridge. This study examined the settlement according to the height and ground stiffness on the MSEW on the IPM Bridge. According to the design guideline, the IPM Bridge (2016) was designed to have a height of 4.0 ~ 10.0m and the elastic settlement was calculated. The base area and the grounding pressure of the MSE wall increased linearly with the height, and the elastic settlement also increased linearly. In addition, the stiffness of the foundations satisfying the allowable settlement of the approach slab is a N value of 35 or more. The settlement of finite element analysis was estimated to be smaller than the elastic settlement, and the stiffness of the foundation ground satisfied the allowable settlement of the approach slab above N value of 20. Because the elastic settlement of the MSEW of the IPM Bridge was overestimated, it will be necessary to examine it carefully by finite element analysis.

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.

Design of Optical Filter with Multilayer Slab/Fiber Structure (다층 슬랩-광섬유접속구조를 갖는 광필터의 설계)

  • Jeoung, Chan-Gwoun;Kang, Young-Jin;Kim, Sun-Youb
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.6
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    • pp.1369-1375
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    • 2007
  • The recent, a large capacity of telecommunication networks is required in order to it is in proportion to capacity of information communication increase and to satisfy a demand because of the demand about Internet, a multimedia service of internet, Video of internet protocol(VoIP), Audio/Video streaming. As a result, DWDM(Dense Wavelength Division Multiplexing)technologies are emerging to be a prevailing the method of solving it without additional optical fiber network building and high-speed equipment. Therefore this thesis proposed the optical filter of fiber/multilayer slab coupled structure combining it to multilayer slab waveguide by polishing the cladding of one side of fiber to design the optical filter having these functions. When a separation distance of fiber and slab was $3{\mu}m$, The optical filter proposed as the simulation result was satisfied with a DWDM filter characteristic with FWHM of 0.1nm on TM mode and TE mode as 32nm polarization independence in a communication window of $1.3{\mu}m$ when center wavelength was each ${\lambda}_0=1.274755{\mu}m$ and ${\lambda}_0=1.30591{\mu}m$.

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The Allowable Displacement Limit on the Approach Slab for a Railway Bridge with Ballastless Track (콘크리트궤도부설 교량의 접속슬래브 허용변위한도에 관한 연구)

  • Choi, Jin-Yu;Yang, Shin-Chu;Yoo, Jin-Young;Cho, Hyun-Cheol
    • Proceedings of the KSR Conference
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    • pp.1149-1155
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    • 2007
  • The transition area between a bridge and an earthwork is one of the weakest area of track because of the track geometry deterioration caused unequal settlement of backfill of abutment. In case of a ballastless track, the approach slab is installed to prevent the phenomenon. But, if there is occurred the inclined displacement on the approach slab by a settlement of the foundation or formation, the track is also under the inclined displacement. And this defect causes reducing the running stability of a vehicle, the riding comfort of passengers, and the deteriorations of track by excessive impact subjected to the track. In this study, parametric studies were performed to know what is the allowable displacement limit on the approach slab to avoid such a bad effect. The length and amount of unequal settlement of the approach slab was adopted as parameter for numerical analysis. And car body accelerations, variations of wheel force and rail stress and uplift force induced on a fastener clip are investigated. From the result, resonable settlement limits of an approach slab according to slab length was suggested.

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Analysis of Relation between Foundation Stiffness and Deformation below Widening Portland Cement Concrete Pavement Sections (시멘트 콘크리트 포장확장시 포장하부지반의 강성과 변위발생의 상관성 분석)

  • Yang, Sung-Chul;Lim, Yu-Jin
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.6
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    • pp.41-49
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    • 2009
  • Poor compaction of subgrade soil causes low stiffness and bearing capacity of sublayers so that faulting and differential settlements can be generated between new and old pavement surfaces in case of widening works. However, investigation of verifying the reason of producing the defects in the pavements are not performed in detail. In this study, several in-field tests including PMT and PBT were performed for obtaining stiffness of the sublayers in new and old pavements respectively of an widening project. Then, based on the obtained stiffness values and the measured deformations obtained by specially designed tilt meters, the main reasons of generating different deformations between the old and new pavement sections and the relationship between the deformation and stiffness are verified.