• Title, Summary, Keyword: Concrete Slab Track

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Trial Installation and Performance Evaluation of Prefabricated Concrete Slab Track on Revenue Line (프리캐스트 콘크리트 슬래브궤도의 영업선 시험시공 및 성능평가)

  • Jang, Seung-Yup;Kang, Yun-Suk;Lee, Hu-Sam;Kim, Yu-Bong;Lee, Jong-Soo
    • Proceedings of the KSR Conference
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    • pp.840-845
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    • 2008
  • To develop our original technology of concrete slab track, being widely accepted for new track, prefabricated concrete slab track, or precast concrete slab track has been developed. They have two different types according to slab shape and its dimensions, connection of slabs and connecting structure onto substructure. After the system design and successful performance evaluation in the laboratory, the trial installation on revenue line has been carried out. This paper is presenting the result of the trial installation and the performance tests in field. The performance tests have been performed as visual inspection for cracks and damages, measurement of track alignment and elastic behavior of track under passing trains. The performance test results during last 2 years have shown that no remarkable damages and settlements were found, and track alignment and elastic track behavior both exhibits good status.

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Correlation Analysis between Crack and TQI in RC Slab Track

  • Kwon, Se-Kon;Park, Mi-Yun;Kim, Doo-Kie;Sho, Byung-Choon;Park, Jae-Hak
    • International Journal of Railway
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    • v.7 no.1
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    • pp.8-15
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    • 2014
  • Recently, in the total railroad construction field, concrete slab tracks have been adapted in place of ballast tracks. Because ballast tracks need frequent maintenance and are difficult to handle due to increasing maintenance costs, eventually concrete slab tracks were selected as an alternative. However, owing to the hydration heat reactions and temperature-affected shrinkage of the concrete, a variety of studies to solve maintenance problems related to concrete slab tracks are underway. This study analyzed characteristics of TQI values evaluating track irregularity, investigated the relationship between crack progress and TQI, and then evaluated the correlation between the two values. Through our analysis, we found that there is a need to supplement the problems of the current method and develop a track evaluation index which takes cracking into account. We also concluded that TQI is the main decision-making tool in track maintenance.

Bond-slip constitutive model of concrete to cement-asphalt mortar interface for slab track structure

  • Su, Miao;Dai, Gonglian;Peng, Hui
    • Structural Engineering and Mechanics
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    • v.74 no.5
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    • pp.589-600
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    • 2020
  • The bonding interface of the concrete slab track and cement-asphalt mortar layer plays an important role in transferring load and restraining the track slab's deformation for slab track structures without concrete bollards in high-speed railway. However, the interfacial bond-slip behavior is seldom considered in the structural analysis; no credible constitutive model has been presented until now. Elaborating the field tests of concrete to cement-asphalt mortar interface subjected to longitudinal and transverse shear loads, this paper revealed its bond capacity and failure characteristics. Interfacial fractures all happen on the contact surface of the concrete track slab and mortar-layer in the experiments. Aiming at this failure mechanism, an interfacial mechanical model that employed the bilinear local bond-slip law was established. Then, the interfacial shear stresses of different loading stages and the load-displacement response were derived. By ensuring that the theoretical load-displacement curve is consistent with the experiment result, an interfacial bond-slip constitutive model including its the corresponding parameters was proposed in this paper. Additionally, a finite element model was used to validate this constitutive model further. The constitutive model presented in this paper can be used to describe the real interfacial bonding effect of slab track structures with similar materials under shear loads.

A Behavior Analysis of HSR concrete slab track under Variety of Rail pad stiffness on fatigue effect (피로효과를 고려한 레일패드 스프링계수 변화에 따른 콘크리트 슬래브 궤도의 거동분석)

  • Eom, Mac;Choi, Jung-Youl;Chun, Dae-Sung;Park, Yong-Gul
    • Proceedings of the KSR Conference
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    • pp.340-350
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    • 2007
  • The major objective of this study is to investigate the fatigue effects of rail pad on High Speed Railway with concrete slab track system. It analyzed the mechanical behaviors of HSR concrete slab track with applying rail pad stiffness based on fatigue effect(hardening and increasing stiffness) on the 3-dimensional FE analysis and laboratory test for static & dynamic characteristics. As a result, the hardening of rail pad due to fatigue loading condition are negative effect for the static & dynamic response of concrete slab track which is before act on fatigue effect. The analytical and experimental study are carried out to investigate rail pad on fatigue effected increase vertical acceleration and stress and decrease suitable deflection on slab track. And rail pad based on fatigue effect induced dynamic maximum stresses, the increase of damage of slab track is predicted by adopting fatigue effected rail pad. after due consideration The servicing HSR concrete slab track with resilient track system has need of the reasonable determination after due consideration fatigue effect of rail pad stiffness which could be reducing the effect of static and dynamic behavior that degradation phenomenon of structure by an unusual response characteristic and a drop durability.

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Research directions for maintenance criteria in Slab Track (콘크리트궤도 유지보수기준 정립을 위한 연구방향)

  • Eom, Jong-Woo;Lee, Myung-Suk;Kwon, Jin-Soo;Kim, Soo-Jung
    • Proceedings of the KSR Conference
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    • pp.979-987
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    • 2011
  • The Ballast Track has been widely applied in traditionally due to low initial cost and abundant elastic property. But the disadvantages of Ballast track are; labor-intensive and costly maintenance, weak in high-speed and heavy axial load, in additionally need wide cross section of tunnel and massive substructure in viaduct. Therefore, recent applications tend to more and more towards slab track such as Gyeungbu high speed rail and existing line. The slab track increased the stability, resistance and durability of track, and save maintenance cost compare to the Ballast Track. But the slab track have weakness of track elongation by sub-ballast differential settlement and that threat safety of train operation. Therefor the slab track need to prevent cracks in concrete ballast for insure the durability of slab track. In this paper, review main items and its expected effects of the slab track maintenance standards that control sub-ballast settlement and concrete ballast cracks.

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A Study on Behavior of Concrete Slab Track subjected to High Speed Train Loads (고속열차하중을 받는 슬래브궤도의 동적거동에 관한 연구)

  • 조병완
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • pp.485-492
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    • 2000
  • In the rail facilities the rail track consists of rail tie fastening accessories and bed,. The rail track is largely divided into Ballast Bed Track(BBT) and Concrete Bed Track(CBT) according to the type of bed. In this thesis among Concrete Bed Track slab track which is used for the Japanese high speed railway is a target of this study. Dynamic analysis by using finite element method are performed. where moving rain load is periodic function. Then through parametric study some conclusions are obtained as follow. Cement Asphalt Mortar(CAM) affects contrary mechanical behavior to rail and slab greatly. Therefore change of CAM spring coefficient should be handled with care, For slab thickness thin slab is more profitable to reduction of vibration of rail than thick one but mechanical capacity of slab is deteriorated, Improved structural type is proposed then structural analysis is performed for this one. This type is effective to reduction of vibration of railway system.

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Dynamic Behavior of Train and Track at Slab Joints of Floating Slab Track (플로팅 슬래브궤도 슬래브 연결부에서의 차량 및 궤도의 동적 거동)

  • Jang, Seung-Yup;Yang, Sin-Chu;Hwang, Sung-Ho;Ahn, Mi-Kyung;Choi, Won-Il
    • Proceedings of the KSR Conference
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    • pp.993-997
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    • 2011
  • Highlighted is significance of the floating slab track for mitigating vibrations induced by train, together with the recent trends towards speed-up of railways. In the design of the floating slab track, it is more beneficial to increase the slab length since a significant impact can be induced on the train and track at the discontinuous points between slabs with the finite slab length. However, if the slab length is too long, the tensile stress of slab concrete and the additional stress on rail due to the temperature change and shrinkage of concrete slab. Thus it is of great importance to relevantly determine the slab length. In this study, to understand these phenomena and establish the countermeasures, the dynamic behaviors of train and track at the inter-slab discontinuous points have been explored and the effect of dowel joints as one of countermeasures has been analytically investigated.

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The Behaviour of Track/Railway Bridge according to Pad Stiffness of Fastener System on Concrete Slab Track (콘크리트슬래브궤도 체결장치의 패드강성에 따른 궤도/교량의 거동 분석)

  • Lee, Jun-Ho;Sung, Deok-Yong;Park, Yong-Gul;Kim, Sung-Il
    • Proceedings of the KSR Conference
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    • pp.1628-1636
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    • 2008
  • Construction of concrete slab track is trending to increase gradually in national and international for reduction in track maintenance cost and secure of ride comfort. But elastic pad becomes superannuated due to repeated train operation. After all, it brings change of pad stiffness and it could directly act on track and bridge as load transmission and impact force. In this study, we carried out laboratory test changing pad stiffness after making a model of 15m bridge and laying concrete slab track. Also, we carried out static and dynamic behaviors test(stress, natural frequency, damping ratio, vibrational acceleration, deflection) of bridge and track and experimentally analyzed them by change of elastic pad stiffness on rail fastener.

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A Study on the Criteria of Settlement in Concrete Slabtrack (토노반상 콘크리트궤도의 노반허용침하기준설정에 관한 연구)

  • Hong, Chul-Kee;Yang, Shin-Chu;Kim, Yun-Tae
    • Journal of the Korean Society for Railway
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    • v.10 no.3
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    • pp.355-364
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    • 2007
  • Recently a concrete slab tracks are being constructed on roadbed in the Gyoeng-bu 2nd phase high speed railways. In respdnding to this trend, new design standards and track materials maintenance systems, based on the slab track material safety and usage perspective, are needed. This research provides a roadbed design criteria and the maintenance system. The proposed roadbed design criteria and the maintenance system are based on the developed analysis meathod of train/slab-track interaction. where the roadbed settlement and train speed are utilized as mediating variables. In the analysis, the dynamic response of train/slab-track interaction apply to various speeds and settlements. the roadbed settlement is shown in a sinusoidal shape of wave, the scope of the settlement occurrence presented in its wavelengths, include 6meters, 10meters, 15merwes, 20meters, 30meters. The train speeds involved are 50, 100, 150, 200, 250, 300, 350, 400kilometers per hour.

3- D Analysis of Concrete Slab Track System (콘크리트 슬래브 궤도의 3차원 거동해석)

  • Kim, Jeong-Il;Jang, Seung-Yup
    • Proceedings of the KSR Conference
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    • pp.955-960
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    • 2004
  • In this study, three dimensional FE analysis of concrete slab track has been performed in order to develop the realistic design of precast concrete slab track. The precast slab track system including the precast concrete slab panel and the grout layer is modeled using the three dimensional solid element with crack softening effect. The input load is computed from the one dimensional beam element model constituting the rail and several discrete springs. To investigate the effect of the longitudinal connection of slab panels, two different systems-continuous and discrete systems - are modeled. The analytical results show that the stresses of both the slab panel and the grout layer are in the range of linear elastic, and, at the interface between two adjacent panels, the primary stresses of the grout layer of the discrete system are higher than those of the continuous system. However, The overall stress levels of the grout layer are very low relative to the strength of th grout.

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