• Title, Summary, Keyword: 광폭침목

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Development of Wide Prestressed Concrete Sleeper for Asphalt Concrete Track (아스팔트 콘크리트 궤도용 광폭 PSC침목 개발)

  • Bae, Young-Hoon;Lee, Seong-Hyeok;Kim, Eung-Rok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.2
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    • pp.34-42
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    • 2018
  • In order to minimize the deformation of asphalt concrete track(ACT) and ensure the structural safety, a wide type concrete sleeper is necessary to distribute vehicle loading and reduce the exposure of the asphalt roadbed. In this research, the wide prestressed concrete(PSC) sleeper for ACT was developed through the shape design and the structural safety was reviewed using finite element analysis. Furthermore, static test, dynamic test and fatigue test were carried out according to EN13230-2 to verify the design appropriateness of the wide PSC sleepers for ACT. The performance test showed that the developed wide PSC sleeper for ACT meets all the performance requirements by European standard.

Evaluation of Flexural Strength of Wide Sleepers with Reinforcing Bars for Quick-Hardened Concrete Track (보강철근이 적용된 급속경화궤도용 광폭침목의 보유 휨 내력 평가)

  • Bae, Young-Hoon;Lee, Il-Wha
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.2
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    • pp.702-709
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    • 2018
  • A quick-hardened concrete track was developed to improve the aged ballasted track to a concrete track, and applied to earthworks and tunnels of main and urban railways. Rebars for reinforcement are not generally applied to prestressed concrete sleepers. On the other hand, many cracked sleepers have been observed in railroad sites. A wide sleeper, which is one of the main components of quick-hardened concrete track, should be structurally safe and crack-resistant in a ballasted and concrete track to avoid this problem. In particular, a wide sleeper manufactured by a post-tension method must have reinforcing bars applied to the rail-seat section. In this paper, static tests, dynamic tests, and fatigue tests were carried out to compare the flexural strength and crack resistance performance of a wide sleeper with and without reinforcing bars for a quick-hardened concrete track. As a result of the test, if some reinforcing bars are applied appropriately to the rail-seat section of a wide sleeper, it will be possible to prevent the occurrence of cracks, delay the expansion of the crack width, and the flexural fracture.

Design Graphs for Asphalt Concrete Track with Wide Sleepers Using Performance Parameters (성능요소를 반영한 광폭 침목형 아스팔트콘크리트 궤도 설계그래프)

  • Lee, SeongHyeok;Lim, Yujin;Song, Geunwoo;Cho, Hojin
    • Journal of the Korean Society for Railway
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    • v.19 no.3
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    • pp.331-340
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    • 2016
  • Wheel load, design velocity, traffic amount (MGT), stiffness and thickness of sub-layers of asphalt concrete track are selected as performance design parameters in this study. A pseudo-static wheel load computed considering the dynamic amplification factor (DAF) based on the design velocity of the KTX was applied to the top of asphalt concrete track for full three dimensional structural analysis using the ABAQUS program. Tensile strains at the bottom of the asphalt concrete layer and vertical strains at the top of the subgrade were computed from the structural FEA with different combinations of performance parameter values for one asphalt concrete track section. Utilizing the computed structural analysis results such as the tensile strains and the vertical strains, it was possible to develop design graphs to investigate proper track sections for different combination of the performance parameters including wheel load, design velocity, traffic amount(MGT), stiffness and thickness of asphalt concrete layers for any given design life. By analyzing the proposed design graphs for asphalt concrete track, it was possible to propose simple design tables that can be used by engineers for the effective and fast design of track.

Development of Device to Resist Horizontal Displacement of Asphalt Concrete Track (아스팔트콘크리트 궤도용 궤도변위 저항 장치 개발)

  • Lee, Seonghyeok;Yoon, Wooyong;Bae, Younghoon
    • Journal of the Korean Society for Railway
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    • v.19 no.6
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    • pp.744-754
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    • 2016
  • Asphalt concrete track (ACT) is a track system connecting wide sleepers and concrete panels on top of an asphalt concrete layer; such a system requires adequate resistance force against various longitudinal and lateral external loads. In this study, a series of experiments were carried out to assess the longitudinal and lateral resistance force of a wide sleeper and concrete panel type ACT. The required shear resistance force of the horizontal displacement restraint device (HDRD) was evaluated. Furthermore, a concrete block type anchor and a steel pipe type anchor were developed as HDRDs. The shear resistance force was decided based on the experimental results of horizontal shear tests for each anchor system. In addition, proper numbers and arrangement design guidelines for the HDRDs were suggested considering the shear resisting capacity and economics for HDRDs applied to ACT.

Performance Evaluation of Modified Wide Sleepers(MF-140 PSC Sleepers) (수정된 광폭침목(MF-140 PSC 침목)의 성능평가)

  • Bae, Young-Hoon;Lee, Il-Wha;Jeong, Chan-Min
    • Proceedings of the KSR Conference
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    • pp.1667-1673
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    • 2011
  • For performance evaluation of modified wide sleepers(MF-140 PSC sleepers), design moment for urban transit was calculated and then performance evaluation criteria were set up according to EN 13230-2. Next, static bend tests, dynamic tests at rail seat section of sleeper were carried out and static bend tests at center section of sleeper were fulfilled. The test results for modified wide sleepers were in excess of performance evaluation criteria and structural safety of sleepers was able to guaranteed from the results. As modifying depth of wide sleepers, construction convenience in underground will be expected to be improved and construction costs will be expected to be decreased.

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