• Title/Summary/Keyword: Reinforced Roadbed

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Using the Turnout Reinforced Concrete Sleeper on Slab Track (콘크리트 도상 분기 침목의 R.C 침목화)

  • 이상진;김기훈;신순호;이인세
    • Proceedings of the KSR Conference
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    • 2002.10a
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    • pp.633-641
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    • 2002
  • Wooden-sleeper, which has been adopted as railway turnout in Korea, has created many problems such as short life span and increase of maintenance cost. Especially turnout on Maintenance Free slab track, which has been used in city metro, has been constructed with wooden sleeper buried in concrete roadbed due to complexity of structure. However, such problem as rapid erosion in subground makes it difficult to maintain the sleeper because of frequent replacement required. Therefore, the objective of this paper is to introduce design and construction of reinforced concrete(R.C) sleeper for turnout on the concrete roadbed to facilitate maintainability and economic construction of turnout.

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Optimal Section of Ballasted Asphalt Track Considering Design Lifetime and Economic Feasibility (설계수명 및 경제성을 고려한 유도상 아스팔트 궤도의 최적 단면 산정)

  • Lee, Seonghyeok;Lee, Jinwook;Lee, Hyunmin
    • Journal of the Korean Society for Railway
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    • v.18 no.3
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    • pp.241-251
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    • 2015
  • Compared with ballasted track (BT), ballasted asphalt track (BAT) has been increasingly adopted in many countries due to its more greatly reduced reinforced roadbed thickness and smaller cumulative plastic deformation, and its advantages in terms of maintenance. In this respect, the authors' previous research includes analysis of BAT sections that show performance similar to that of BT sections of the present specifications; reliability verification of the analysis results through real-sized static and dynamic train-load tests were performed. Based on previous research, this paper estimates the track lifetime using the strain of the lower roadbed according to reinforced roadbed thickness; using probabilistic LCC analysis, this paper presents a BAT section that satisfies the design lifetime and that has performance similar to or higher than that of BT.

Assessment of Geosynthetic Soilbag Method to Restore the Roadbed of Railway (철도노반 복구를 위한 토목섬유 Soilbag 공법의 적용성 평가)

  • Hwang, Seon-Keun;Koh, Tae-Hoon;Park, Sung-Hyun
    • Journal of the Korean Society of Hazard Mitigation
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    • v.4 no.1 s.12
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    • pp.65-75
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    • 2004
  • Roadbed failure due to the natural disaster may bring out social and economic damage such as the loss of life and property, the consumption of time and cost for recovery, and the delay of logistics in railway In this study, the method using geosynthetic soilbag was applied to rehabilitation of the railway roadbed which was failed by disaster. The full scale tests with the simulated train loading were performed in order to evaluate the static and dynamic performance at the railway roadbed using geosynthetic soilbag. The results of these tests were compared with unreinforced and reinforced cases with geosynthetic soilbag, respectively The data gathered by various measurement devices from these full scale tests would be useful to evaluate and understand the roadbed with geosynthetic soilbag. In conclusion, geosynthetic soilbag was evaluated as a permanent restoration method to reinforce the roadbed of railway.

Analysis of Geotextile Bag Reinforcing Effect on Railway Roadbed (지오텍스타일 백을 이용한 철도노반 보강효과 분석)

  • Lee, Dong-Hyun;Shin, Eun-Chul
    • Journal of the Korean Geosynthetics Society
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    • v.4 no.4
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    • pp.3-11
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    • 2005
  • In this study, a large-scale laboratory model test and 2-D numerical analysis were conducted to verify the reinforcement effect by utilizing geotextile bag on the railway roadbed. Static loading which simulated train load was applied on the geotextile-reinforced railway roadbed and also unreinforced railway roadbed. Computer program named Pentagon 2-D which is a part of FEM programs was used in the numerical analysis. Based on the results of laboratory test and 2-D numerical analysis, the effect of load distribution and settlement reduction was found to be depending on the geotextile characteristics, tensile strength of geotextile, and interface friction angle between geotextile bags. In general, the result of 2-D numerical analysis shows lower value than that of laboratory test.

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Development of Short-fiber Composite Reinforced Retaining Wall for Railroad Soil Structure (노반 토구조물로서의 이용을 위한 새로운 단섬유 복합보강토 옹벽구조 개발)

  • Park Young-Kon;Park Tae-Soon;Chang Pyoung-Wuck;Lee Young-Je
    • Proceedings of the KSR Conference
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    • 2004.06a
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    • pp.1014-1019
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    • 2004
  • The development of both economical and consistent structure is strongly required for the whole reorganization of the railway network in Korea. Retaining wall is one of the major structures in the vicinity of the railway, which needs improving its external appearance and stability. Therefore, this study presents a new type of retaining wall, so called short-fiber composite reinforced retaining wall, as an alternative of retaining walls, which can be used for constructing the slope and roadbed soil structures. The results from real-scale test and dynamic numerical analysis for developed new one, which helps both the improvement of the external appearance and also the optimum use of the limited space near the railway, show excellent performance. On the basis of these results, it is judged that short-fiber composite reinforced retaining wall has the advantages of choosing the front wall freely and having a chance to use any low quality soil as backfill.

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Estimation of Reinforced Railway Roadbed by Geosynthetics on Frost and Bearing Capacity (토목섬유로 보강된 철도노반의 동상 및 지지력 평가)

  • 심재범;채영수
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.11c
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    • pp.117-128
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    • 1999
  • Geosynthetics have been studied especially Korean Railway earth works from the outset and have proved successful in both technical and economic terms. Hitherto Geosynthetics have been given consideration chiefly in dimensioning the requisite track subbase thickness, but have not been considered when calculating the thickness of the frost protection layer. this often made it impossible to reduce the thickness of the subbase. The article therefore puts forward a proposal for considering the German Geosynthetics in dimensioning the requisite thickness of the frost protection layer.

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A Study on Transferred Load Reduction on Paved Track Roadbed with Low Elastic Base Plate Pad (저탄성 베이스플레이트 패드 적용에 따른 포장궤도 노반에서의 전달하중 저감에 관한 연구)

  • Lee, Il-Wha;Kang, Yun-Suk;Lee, Hee-Up
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.3D
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    • pp.399-405
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    • 2008
  • Development of the paved track is required as a low-maintenance of conventional line. The paved tracks are one of the types of the ballast reinforced tracks those are manufactured by adopting the prepacked concrete technique. The main elements of this tracks are large sleeper, low elastic pad, fastener, cement mortar, geotextile and recycled ballast. Low elastic pad is the most effective element of such tracks on the basis of stress-displacement characteristics, dynamic response and fatigue characteristics. The stiffness of the pad determine the stiffness of the track. Consequently, it is more important in case of concrete track structure such as paved track because application of low elastic pad seriously effect the durability and stability of the track. The main objective of this study is to confirm the reduction of train load, which transfer to roadbed through various pad effects. To achieve this task static, numerical analysis and real scale repeated loading test was performed while load reduction effect of low elastic pad was analyzed by using displacement, stress and strain ratio characteristics of the paved track.

Measurements and Analysis of Deformation States in Roadbed in Gyeongbu High Speed Railway (경부고속철도 토공부에 대한 변형상태 계측 및 분석)

  • Jin, Nam-Hee;Kim, Nam-Hyuk;Shim, Hyun-Woo
    • Proceedings of the KSR Conference
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    • 2009.05a
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    • pp.1542-1549
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    • 2009
  • The function of subgrade in the railway is to support track load on the subgrade as well as train load. Unlike the traditional railway, the uppermost subgrade layer in the Gyeongbu high speed railway was constructed as the reinforced road bed. The reinforced road bed comprises sub-ballast in the upper part and grade ballast in the lower part. The filling material such as soil and rocks in the subgrade can be settled by consolidation of original ground, compression due to self weight, plastic displacement due to train operation, and unequal settlement due to embankment material or improper compaction, therefore many efforts have been given for sufficient compaction and use of proper filling materials in the construction stage. The purpose of this study is to investigate the deformation state of subgrade in the Gyeongbu high speed railway. The investigation on the subgrade settlement was performed by choosing representative sections suspected to be settled based on the previous GPR test results and track maintenance history, measuring the settlement for some time period after installing settlement measuring instruments on and under the reinforced road bed. and analyzing the long-term subgrade settlement data from monitoring system which was installed at the construction stage of the high speed railway.

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