• Title, Summary, Keyword: Railway track

Search Result 1,513, Processing Time 0.048 seconds

The Parameter Study of Serviceability Review of End Track on Railway Bridge installed Concrete Slab Track (콘크리트궤도 부설 교량의 단부 사용성 검토를 위한 매개변수 연구)

  • Sung, Deok-Yong;Kim, Young-Ha;Park, Yong-Gul;Kim, Sung-Il
    • Proceedings of the KSR Conference
    • /
    • /
    • pp.117-124
    • /
    • 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. However, in case of railway bridge installed concrete slab track, the serviceability review of end deck should be performed for reducing the maintenance cost of track. The serviceability review of track contains that the compression force which is occurred on fastener of end bridge should be smaller than the compression force causing the deformation limit of elastic pad and the uplift force which is occurred on fastener of end abutment should be smaller than initial fastening force. Therefore, this study calculated the deflection and end rotation of the railway bridge according to the span length and stiffness of railway bridge and estimated the compression force and uplift force which are occurred on the track of end bridge using the finite element method. This study indicated the several diagrams that are contained the correlation between the behaviour of the track and the behaviour of the railway bridge. As a result, to reduce the end rotation of the railway bridge is very efficient to increase the height of railway deck.

  • PDF

The Dynamics Responses of Railway Bridges Considering the Track Model (궤도모형에 따른 철도교량의 동적응답분석)

  • Kim, Sang-Hyo;Lee, Yong-Seon;Jung, Jun;Lee, Jun-Suk
    • Proceedings of the KSR Conference
    • /
    • /
    • pp.715-720
    • /
    • 2002
  • The dynamic load effects, generated by moving trains, are transferred to the railway bridges through tracks. The dynamic load effects may vary due to the dynamic characteristics of the applied vehicle loads and the railway bridges including the track system. However, the track models have been neglected or simplified by spring elements in the most studies since it is quite complicated to consider the track systems in the dynamic analysis models of railway bridges. In this study track system on railway bridges are modeled using a three-dimensional discrete-support model that can simulate the load carrying behavior of tracks. A 40m simply supported prestressed concrete box-girder system adopted for high-speed railway bridges are modeled for simulation works. The train models are composed of 20 cars for KTX. The dynamic response of railway bridges are found to be affected depending on whether the track model is considered for not. The influencing rate depends on the traveling speed and different wheel-axle distance. The dynamic bridge response decreases remarkably by the track systems around the resonant frequency. Therefore, the resonance effect can be reduced by modifying the track properties in the railway bridge, especially for KTX trains.

  • PDF

Optimization of Suspension Under the Condition of Curved Track in Railway Vehicle

  • Choi, Jong Yoon;Li, Zheng Yuan;Baek, Seung Guk;Song, Ki Seok;Koo, Ja Choon;Choi, Yeon Sun
    • International Journal of Railway
    • /
    • v.7 no.2
    • /
    • pp.57-63
    • /
    • 2014
  • This paper presents the optimization of suspension characteristics under the condition of curved track railway vehicles. Reducing lateral acceleration on curved track is an issue for high-speed railway vehicles. In terms of curved track running environments, reducing the lateral vibration of railway vehicles is critical to safety and curving performance. The properties of lateral damping and stiffness of both primary and secondary suspension show effect on wheel-set, bogie and car-body. Analysis for reducing the lateral vibration of rail vehicles with respect to the characteristics of both primary and secondary suspension has been developed using ADAMS/Rail. Response Surface Method has been chosen for the purpose of verifying correlation effects among design parameters. Also, this paper suggests the method for designing optimal suspension of railway vehicles on curved track. The optimization result indicates decrement of lateral acceleration on wheel-set by 3% and bogie by 1% on curved track. Finally, this paper comes to the conclusion that suspension system of railway vehicle (KTX I) is properly designed when regarding lateral vibration of railway vehicle on diverse curved track condition.

Design Loads on Railway Substructure: Sensitivity Analysis of the Influence of the Fastening Stiffness

  • Giannakos, Konstantinos
    • International Journal of Railway
    • /
    • v.7 no.2
    • /
    • pp.46-56
    • /
    • 2014
  • The superstructure of the railway track undertakes the forces that develop during train passage and distributes them towards its seating. The track panel plays a key role in terms of load distribution, while at the same time it maintains the geometrical distance between the rails. The substructure and ballast undergo residual deformations under high stresses that contribute to the deterioration of the so-called geometry of the track. The track stiffness is the primary contributing factor to the amount of the stresses that develop on the substructure and is directly influenced by the fastening resilience. Four methods from the international literature are used in this paper to calculate the loads and stresses on the track substructure and the results are compared and discussed. A parametric investigation of the stresses that develop on the substructure of different types of railway tracks (i.e. balastless vs ballasted) is performed and the results are presented as a function of the total static track stiffness.

Developing Track Ballast Characteristic Guideline In Order To Evaluate Its Performance

  • Sadeghi, J.M.;Zakeri, J. Ali;Najar, M. Emad Motieyan
    • International Journal of Railway
    • /
    • v.9 no.2
    • /
    • pp.27-35
    • /
    • 2016
  • In spite of recent advances in ballasted railway track, the correct choice of ballast for rail track is still considered critical because aggregates progressively deteriorate under traffic loading and environmental exposures. Various ballast requirements, functions and duties have been defined by researchers, railway companies and countries' regulations even though it needs to be integrated to make following proper decision during track operation and maintenance. A proper understanding of ballast properties and suitable tests are prerequisites for minimizing maintenance costs. This paper presents a capable classification for ballast characteristics which need to be investigated beforehand to such a way, firstly to assign ballast functions, secondly need to clarify ballast requirements, thirdly to map appropriate tests to evaluate ballast characteristics and then it must be such that if ballast cannot carry out one of these duties, be able to call there is ballast defect. The paper is structured in order to achieve these objectives.

Parametric Analysis in Dynamic Characteristics of Railway Track due to Travelling Vehicle (주행차량에 의한 궤도 동적?성의 매개변수 분석)

  • Kim Sang-Hyo;Lee Yong-Seon;Cho Kwang-Il
    • Proceedings of the KSR Conference
    • /
    • /
    • pp.337-342
    • /
    • 2003
  • The dynamic load effects are conveyed to the railway bridges through tracks which are generated by moving trains The dynamic load effects may vary due to the dynamic characteristics of the applied vehicle loads and the railway bridges containing the track system. However, the track effects have been neglected or simplified by spring elements in the most studies since it is quite complex to consider the track systems in the dynamic analysis models of railway bridges. In this study, track system on railway bridges is modeled using a three-dimensional discrete-support model that can simulate the load carrying behavior of tracks. In addition, this program is developed with the precise 20-car model and a continuous PSC(prestressed concrete) box girder bridge, which is the main bridge type of Korea Train express(KTX). Three-dimensional elements are used for both. The dynamic response of railway bridges is found to be affected depending on whether the track model is considered or not. The influencing rate depends on the traveling speed and different wheel-axle distance. The dynamic bridge response is decreased remarkably by the track systems around the resonant frequency. Therefore, the resonance effect can be reduced by modifying the track properties in the railway bridge.

  • PDF

Experimental Study on the Evaluation of Behavior for Floating Track System Using a Resilient Rubber Mat (고무방진매트가 적용된 플로팅궤도시스템의 거동분석을 위한 실험적 연구)

  • Lee, Siyong;Jeong, Incheol;Choi, Jungyoul;Park, Yonggul
    • Journal of the Korean Society for Railway
    • /
    • v.17 no.4
    • /
    • pp.281-288
    • /
    • 2014
  • The objective of this study was to estimate the vibration reduction capacities of a floating track system using a resilient rubber mat, and to compare the results with the track support stiffness and track impact factor of a conventional slab track system by performing field tests using actual vehicles running along a service line. The theoretically designed track support stiffness and track impact factor were compared with the measured track support stiffness and track impact factor for each tested track. The calculated and measured track support stiffness of the floating track system were found to be similar, and the floating track system satisfied the design specifications of the track impact factor. The overall vibration level and track support stiffness of the floating track system were thereupon found to be significantly lower than those of the conventional slab track system. The experimental results thus showed that the vibration reduction effect of the floating track system is greater than that of the conventional slab track.

Characteristics of Track and Train Behaviors on High-Speed Railway Bridge/Earthwork Transiton Zone (고속철도 교량/토공 접속부에서의 궤도 및 차량 거동 특성)

  • Lee, Il-Wha;Kang, Yun-Suk;Kim, Eun;Son, Ki-Jun;Park, Chan-Kyoung
    • Proceedings of the KSR Conference
    • /
    • /
    • pp.129-134
    • /
    • 2003
  • It is very important to pay careful attention to construction of bridge/earthwork transition zone for high-speed railway. The transition zone of the railway is the section which roadbed stiffness is suddenly varied. Differences in stiffness have dynamic effects and these increase the forces in the track and the extent of deformation. An abrupt change of stiffness across two adjacent track portions cause irregular settlement of roadbed, track irregularity, lack of girder bending moment and reduction of lateral resistance. Especially on high-speed railway, track irregularity of transition zone cause sincere effect to track stability and train safety. And so continuous maintenance is needed. To verify this effect and to improve transiton zone capacity, In situ test, track irregularity and train acceleration test were performed on high-speed railway bridge/earthwork Transiton Zone.

  • PDF

Experimental Study on Applying a Transition Track System to Improve Track Serviceability in Railway Bridge Deck Ends (철도교량 단부 궤도의 사용성 향상을 위한 횡단궤도시스템 적용에 관한 실험적 연구)

  • Lim, Jongil;Song, Sunok;Choi, Jungyoul;Park, Yonggul
    • Journal of the Korean Society for Railway
    • /
    • v.16 no.3
    • /
    • pp.207-216
    • /
    • 2013
  • The components of concrete track (rail and rail fastening system) in railway bridge deck ends are damaged and deteriorated by track-bridge interaction forces such as uplift forces and compression forces owing to their structural flexural characteristics (bridge end rotation). This had led to demand for alternatives to improve structural safety and serviceability. In this study, the authors aim to develop a transition track to enhance the long term workability and durability of concrete track components in railway bridge deck ends and thereby improve the performance of concrete track. A time-history analysis and a three-dimensional finite element method analysis were performed to consider the train speed and the effect of multiple train loads and the results were compared with the performance requirements and German standard for transition track. Furthermore, two specimens, a normal concrete track and a transition track, were fabricated to evaluate the effects of application of the developed transition track, and static tests were conducted. From the results, the track-bridge interaction force acting on the track components (rail displacement, rail stress, and clip stress) of the railway bridge deck end were significantly reduced with use of the developed transition track compared with the non-transition track specimen.

Vibration Characteristics of High-speed Railway Lines on the Type of Track (고속철도 궤도 타입에 따른 진동 특성)

  • Lee, Chan-Woo;Ham, Ham-Young;Kim, Jae-Chul
    • Proceedings of the KSR Conference
    • /
    • /
    • pp.332-336
    • /
    • 2011
  • IN THIS STUDY, BASED ON THE TYPE OF HIGH SPEED RAILWAY TRACK VIBRATION CHARACTERISTICS WERE MEASURED AT KTX VEHICLE. KTX ROUTE BALLASTED TRACK HAS BEEN INSTALLED TOGETHER WITH THE CONCRETE TRACK. CONCRETE MUST BE TRACK IRREGULARITY THAN BALLASTED TRACK, VEHICLES VIBRATION VALUES THAT ARE SMALLER. ALSO, IN TERMS OF MAINTENANCE, CONCRETE TRACK IS KNOWN TO BE MORE FAVORABLE THAN THE BALLASTED TRACK. PHASE 2 IS THE KTX, DAEGU - BUSAN IS A SECTION OF CONCRETE TRACK. IN THIS STUDY, "KUUNG-BU HIGH-SPEED RAILWAY LINES" INSTALLED ON THE CONCRETE TRACK AND BALLASTED TRACK KTX FROM THE VEHICLE WHEN INSTALLED BETWEEN RAILS, SLEEPER AND BALLAST ON THE TRACK WAS MEASURED VIBRATIONS.

  • PDF