• Journal of the Korean Society for Railway
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• v.18 no.1
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• pp.43-52
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• 2015

In this study, to minimize both the costs associated with track maintenance and the energy consumption for train operation, a numerical method that evaluates the optimal vertical stiffness of a fastener for concrete track is presented. A progress model of the track damage is established in order to calculate the concrete track maintenance cost according to the fastener stiffness. Also, the quantitative relationship between the progress of the track damage and the maintenance of the concrete track is derived. The wheel load is more exactly evaluated by using the advanced vehicle-track interaction model, which can precisely consider the behaviors of the track components. An optimal range for the stiffness of the fastener, a range that is applicable to the design of concrete track for domestic high speed lines, is proposed.

• Journal of the Korean Society for Railway
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• v.15 no.2
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• pp.147-153
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• 2012

Precise estimation f a structure's dynamic characteristics is indispensable for ensuring stable dynamic response during life time especially for the structures which can experience resonance such as railway bridges. Especially, concrete track can change the modal properties of the railway bridge, through the contribution of stiffness as well as mass effects, generally only the mass effect is considered in dynamic analysis of the railway bridge. In this paper, static and dynamic behaviors of railway bridge with concrete track were investigated through experimental study. Also, numerical analysis was performed about considering only mass of concrete track and together with stiffness and mass of concrete track. These were compared with experiment value. Numerical analysis value considering together with stiffness and mass of concrete track was similar experiment value. Therefore, when dynamic analysis of railway bridge with concrete track is performed, the contribution of stiffness as well as mass effects for concrete track is considered.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1D
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• pp.125-132
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• 2006

In the present study, in order to elucidate the vibration characteristics of track and train body according to the type of track in tunnel, the vibration accelerations of the track and the KTX train body have been measured in tunnels of Kyong-Bu high-speed railway(HSR) lines, and the frequency analysis of the measured data has been performed. From this, the vibration characteristics of the track components such as rail, sleeper, ballast and slab, the tunnel lining and the vehicle body according to the type of track are investigated and their relation is analyzed. The test results show that the vibration of rail and vehicle body rapidly increases at 80Hz in tunnel, and that is much higher in the tunnel on which the concrete slab track is placed. According to the results of the present study, rail supporting stiffness can variate the vibration characteristics of the total system including the vehicle, and therefore the correlation between the vibration of vehicle should be taken into account to determine the supporting stiffness of the slab track.

• Journal of the Korean Society for Railway
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• v.12 no.1
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• pp.167-174
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• 2009

Due to the travelling of the train with high speed the period of maintenance activities of the ballasted track is coming to be short, and more from the residential area of the ballasted track tunnel circumference the civil appeal is increasing with railroad vibration problem. To reduce the vibration problem and a maintenance cost establishes the ballast mat in the tunnel within part segment. In this study, to estimate the vibration reduction effect of the ballast mat we have done a comparative analysis with the vibration field test by the transit train by at the ballasted track with ballast mat and the standard ballasted track without vibration protection in tunnel.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2072-2076
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• 2011

철도 시스템에서 철도궤도와 레일은 주요한 신호 시스템의 일부로 사용되고 있으나 콘크리트 슬래브 궤도 내부의 철근으로 인한 신호전류 감소, 교란 등을 방지하기 위해 과도한 절연작업이 필요하다. 본 연구에서는 국내에서 기 개발된 프리캐스트 슬래브 궤도의 횡방향 철근을 GFRP 보강근으로 대체하여 절연작업의 감소를 가능하게 하였다. GFRP로 보강된 프리캐스트 슬래브 궤도의 설계과정과 정적 휨 시험과 단부의 연결철근 인발 시험을 통한 거동 분석 및 고찰 내용을 제시하였다. 휨 시험과 실스케일 인발 시험의 결과 정적 휨 강도는 정립된 설계법에 의해 적절한 강도를 가지고 있으나 기 개발된 연결철근의 위치와 형태는 온도 또는 수축으로 인해 발생할 수 있는 축력을 저항할 수 없음을 확인하였다.

• Journal of the Korean Society for Railway
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• v.13 no.6
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• pp.601-607
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• 2010

The objective of this paper is to propose a fast and easy Binary Artificial Bee Colony (BABC) heuristic algorithm to optimize NP-hard scheduling problem of railway track maintenance considering real conditions. The optimal or best solutions can be found using proposed BABC within very short or user specified computation time. We can greatly maximize the objective value using this proposed method in 30, 60, 100 and 200 work size railway track maintenance scheduling problems for experiment and analysis.

• Journal of the Korean Society for Railway
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• v.6 no.4
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• pp.30-36
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• 2003

궤도(track)는 열차가 안전하고 승차감(乘車感)이 좋게 운행되도록 충분한 강도를 가지고 더욱이 양호한 상태로 정비되어 있어야 한다. 일반적으로, 토목구조물(structure)은 하중을 받으면 변위(變位)ㆍ변형하고, 하중이 없게 되면 원래대로 되돌아간다. 즉, 각 부재는 탄성 한계 내로 응력(應力)이 들어가도록 설계된다. 그러나, 궤도는 열차의 하중과 진동을 궤도 자신의 변위 축적으로 흡수하고 있다. 결국, 처음부터 틀림이 진행되어 가는 것을 전제로 한 유일한 구조물이다. 일반적으로는 스프링 하 중량과 축중(軸重)이 큰 차량이 빠르고 대량으로 주행하게 되면 궤도 틀림이 발생하여 진행한다. 궤도 틀림 파형의 성장은 궤도 틀림이라고 하는 공간적인 파형의 시간적인 추이라고 하는 2차원적인 취급이 필요하다. (중략)

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.2
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• pp.110-121
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• 2016

In the decision-making, such as selection of structure, construction method, or time and scheme of maintenance, the evaluation of life-cycle cost(LCC) is of great importance. The maintenance cost occupy a large portion of the LCC of the railway track as well as the initial construction cost. Futhermore, the proportion of the maintenance cost is much higher in the ballasted track. Thus, the importance of the LCC evaluation is higher than in any other engineering structures. In this study, a LCC model that can consider various design parameters such as the type of track structure, annual traffic volume, axle load, train speed, and proportion of curve sections and engineering structures has been developed. Fundamental data for calculating costs also have been presented. Based on the model and data proposed, the trends in the variation of LCC according to the design parameters were examined and the most important design parameters in the LCC analysis of railway track were investigated. The results show that the proportion of renewal and operational costs is much higher in the ballasted track than in the concrete track, and the annual traffic volume and ballast taming period are most significant factors on the LCC of the ballasted track. On the contrary, it is revealed that the proportion of the initial construction costs in the concrete track is much higher, and the LCC of the concrete track is less sensitive to the traffic volume, train speed, and axle load.

• Journal of the Korean Society for Railway
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• v.14 no.3
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• pp.248-255
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• 2011

Impact factor of concrete and ballast track which has been used in Korea railway was applied to equation (1+0.513V/100) from AREA. As the use of this equation, overcapacity of track design might be occurred. Therefore, this study compared impact of ballast track (well, bad) and concrete track (sleeper embeded system, rail floating and sleeper floating) by field test to analyzing dynamic effect of track structure's characterstic and wheel load on service line. In addition, it suggested a method to generate reasonable impact factor on each track type.

• Journal of the Korean Geotechnical Society
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• v.24 no.11
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• pp.25-34
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• 2008

An application of concrete track is being actively processed for the construction of Korean high speed railway. The concrete track has an advantage in decreasing the maintenance cost, whereas it has much difficulty controlling the long term settlement after settlement occurred. Therefore, the management and control of settlement are very important for the successful construction of concrete track. The purpose of this paper is to verify the allowable settlement between concrete track and ballast track, and piled raft foundation installation effects as settlement reducers for concrete track. Therefore, a series of 3D finite element analyses that take into account the allowable settlement were performed for major parameters such as soil condition, pile installation and loading type. Based on the analysis, it is shown that concrete track causes much smaller settlement than ballast track, and the effect of installation is necessary to effectively reduce the settlement of concrete track.