• 한국철도학회논문집
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• 제10권3호
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• pp.296-305
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• 2007

A numerical method for the analysis of train/slab-track interaction on the settled roadbed is developed based on the already developed analysis method of train/ballast-track interaction. The concrete slabs composed of the upper track concrete layer and the lower hydraulic bonded layer are modelled by a equivalent beam. The supporting stiffness of roadbed is evaluated with the modified boussinesq method suggested by Eisenmann. The track irregularity and the gap between slab and roadbed induced by settlement of roadbed are calculated by the effective method newly presented in this study. The validation of the developed method is investigated by a numerical example. The effects of train speed on train and slab track on the settled roadbed with sinusoidal shape of wave length 20m and amplitude 20mm are reviewed.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.639-642
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• 2003

In this paper, fatigue behavior of concrete slab tracks under railway loads by experimental method is discussed. The addition of steel fibers to concrete mix has been receiving more attention as a way of improving the crack behavior of concrete beams an slabs tacks. This study two objectives: 1) to observe the fatigue behavior of fiber reinforced concrete slab in labor, and 2) to present crack propagation and deflection of fiber reinforced concrete slab track under railway loads in the Waghauser test line. Nine beams, two slabs and one test track were experimentally tested.

• 한국철도학회논문집
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• 제19권2호
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• pp.195-203
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• 2016

최근 경부고속철도 2단계와 호남고속철도에 적용된 콘크리트궤도는 초기 건설비는 기존 자갈궤도에 비하여 불리하나, 유지관리비용은 유리한 것으로 검토되었다. 이와 같은 이유로 콘크리트궤도는 일반철도 신설구간을 중심으로 점점 더 적용구간이 늘어나고 있는 실정이다. 그러나 콘크리트궤도의 가장 큰 문제점 중의 하나는 침하로 인한 궤도 보수와 관계된 문제이다. 궤도의 하부 노반침하 및 이로 인한 궤도 안정성 저하는 콘크리트궤도의 가장 큰 단점이고, 고속철도 설계기준에는 허용잔류침하량을 25mm로 제시하고 있다. 콘크리트궤도의 안정성을 위해서는 2차 압축침하량을 기준치 이내로 관리하여야 한다. 본 연구에서는 2차 압축침하에 대한 이론을 토대로 연약지반의 2차 압축지수 및 연약지반 층의 두께 그리고 궤도수명에 따른 2차 압축침하량을 산정하여 궤도구조 선정에 활용하도록 제시하였다. 또한 국내 연약지반의 2차 압축계수의 확률분포 특성을 분석을 통하여, 콘크리트궤도 부설이 불가능한 지역이 10% 이상 나타남을 알 수 있었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1085-1090
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• 2007

In recent railway construction, the concrete slab track is getting highlighted as main stream in track type. However, it is the fact that there are different opinions in selection of the optimized spring coefficient of elastic pad. In this study, the performance of vibration reduction in different stiffness of rail pad for ballasted track was compared, and the changes in characteristics, such as static/dynamic deflection of components, vibration acceleration, insertion loss etc., were analysed by using ISI Program for various types of rail fastening system used in concrete slab track. It was concluded that the fastening system with softer pads has shown the better performance of vibration reduction in concrete slab track and the optimized static stiffness has been calculated to 21.1kN/mm for conventional railways, 17.6kN/mm for high-speed railways and 17.8kN/mm for subways.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2435-2438
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• 2011

Steel bar is used for as a reinforcing material in a concrete slab track. Bacuase the steel re-bar could provide passes for current transition, all the cross points of steel re-bars should be insulated by using plastic materials. This is due to the loss of signal intensity of track-circuit. In this study, GFRP bars are adopted in place of the traditional steel reinforcing bars for a concrete slab track to minimize the loss of the signal intensity. In order to evaluate the replacing effect on eletrical characteristic of slab track, measurements of surface resistivity are conducted on steel and GFRP reinforced precast slab tracks. In the results, the GFRP reinforced slab strack shows the higher resistivity than the steel reinforced slab track.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 춘계학술대회 논문집
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• pp.343-348
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• 2003

As one of countermeasures for vibration and noise source which come from train operation in subway system, the heavy-weighted tunnel structure and the low-vibration track design have been adopted. In recent the low-vibration concrete track have been constructed to enhance the maintenance effectiveness as well as the reduction of vibration. This paper is explaining and evaluating of the characteristics of vibration and its effects comparing to tile ballast track, concrete track, and full surface supported floating slab track installed on Express bus terminal in Seoul subway No. 7 line.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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• pp.379-384
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• 2009

It is of great importance to assure the running safety and ride comfort in designing the floating slab track for the mitigation of train-induced vibration. In this paper, for this, analyzed are the system requirements for the running safety and ride comfort, and then, the behavior of train and track at the transition zone between the floating slab track and the conventional concrete slab track according to several main design variables such as spring constant, damping coefficient, spacing and arrangement of isolators and slab length, using the dynamic analysis technique considering the train-track interaction. The results of numerical analysis demonstrate that the discontinuity of the support stiffness at the transition results in a drastic increase of the vertical vibration acceleration of the train body, wheel-rail interaction force, rail bending stress and uplift force. The increase becomes higher with the decrease of the spring constant of isolators and the increase of the isolator spacing, but the damping ratio does not significantly affect the behavior of train and track at the transition. Therefore, to assure the running safety and ride comfort, simultaneously increasing the effectiveness of vibration isolation, it is effective to minimize the relative vertical offset between the floating slab and the conventional track slab by adjusting the spring constant and spacing of isolators at the transition.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1169-1177
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• 2008

The system of the railway signaling using the track transmits the approved speed to the location of a train and it. Referring to the way of transmitting train control information, there are the one transmitting it to the on-board system of a train using the direct track, the another transmitting it establishing an instrument, and the other transmitting an instrument by a railway track. The one is the method using the direct track as a conductor for composing the part of the track and attaining the information controlling a train by transmitting a signal to the track. It is used for the high-speed railway and the subway. The method using the track attains information by transmitting it to returned information, and the on-board system of a train attains it by magnetic coupling. Because many reinforcing bars on the concrete slab track are used, interaction between a rail and a reinforcing bar that is not produced on ballast track is made. Due to the interaction, the electric characteristic of rail is changed. In the current paper, we numerically computed the coupling coefficient between the rail and the reinforcing bar based on the concrete slab track throughout the model related to the rail and the reinforcing bar using the concrete slab track that is used in the second interval of the Gyeongbu high-speed railway, and we defined the coupling coefficient not changed in the electric characteristic of rail in the condition that there is no interaction between the rail and the reinforcing bar.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.117-124
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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. 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.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.740-744
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• 2011

Precast slab track system(PSTS) is a concrete track laying system where the slab panels are pre-manufactured in factories and assembled and installed on-site. PSTS has been developed for the past 30 years in countries where railway technologies are advanced such as Japan and Germany to improve the various drawbacks of the in-situ concrete slab track. However, the usefulness of PSTS is being continuously approved by many other countries such as China, Taiwan, Austria, Italy, Spain, etc,. Lately, not only Japan and Germany, but also Austria, Italy and China have developed their own PSTS by collaboration between their Governments and private enterprises and are now attempting to expand their businesse soverseas. In accordance to such movement, in 2006, the Korean Railroad Research Institution and Sampyo E&C have developed a Korean PSTS by joint research. PSTS consists of concrete panel, under pouring layer and concrete base layer. Amongst these components, the panel is the main component of PSTS which supports the train load and has a great effect on the track quality, workability and economics. Therefore, a study is to be conducted to select the optimum size for the Panel of the precast slab track system panel by analyzing the various standards & forms, interpretation of finite elements of the selected model and economical analysis.