• 한국구조물진단유지관리공학회 논문집
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• 제5권2호
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• pp.163-174
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• 2001

This paper is to study the characteristics of axial force behavior that operates to the part of turnout when it makes the turnout and the continuous welded rail unifying. The study is to model by using the 50kgN rail No. 15 turnout used in the domestic national railway and the UIC60 rail No. 18 turnout used in the rapid transit railway as the finite elements for analyzing the axial force behavior of the turnout by the continuous welded rail. It is to analyze the characteristics of behavior according to the change of creep resistance, ballast resistance and the change of parameter valuables of heel joint by the axial force simulation in making the continuous welded rail and then, it is to present the result. As the result of research on the parameter valuables through the analysis, it shows that the maximum axial force of turnout by the continuous welded rail are largely subordinated to the maximum resistance of heel joint and the fitting devices than the ballast resistance. Also it shows that the maximum axial force produced changes a lot according to the characteristics of creep resistance of the fitting part and the ballast resistance.

• 한국구조물진단유지관리공학회 논문집
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• 제7권1호
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• pp.251-258
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• 2003

This study is to understand the characteristics of axial force behavior that operates to the part of continuous welded rail and to investigate the basic data for secure the structure's stability and retrofit of the track. To develop the FEM model that type of plate girder which is used in the domestic national railway among servicing railway type. It is to analyze the characteristics of axial force behavior according to equip of the expansion joint and support placing by using the axial force simulation in making the continuous welded rail. As the result of research on the parametric valuables through the analysis, it is investigated that 'FMFM type' is more efficient than the other support type. Also, it conclude that structures are having the expansion joint is the most safe condition.

• 한국철도학회논문집
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• 제8권3호
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• pp.276-285
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• 2005

This study discussed the effect on rail's axial force due to thermal and seismic loads according to supporting conditions of railway bridges; the considered supporting conditions are 1)simply supported, 2)roller at both ends, and 3)roller with horizontal spring at both ends. Closed form solutions are used to calculate the axial farces on rails. The roller at both ends of a bridge span decreases the compressive axial force on rail due to thermal load compared with the simply supported condition. However, the lateral springs at roller are not helpful to decrease the rail's compressive axial force.

• 한국구조물진단유지관리공학회 논문집
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• 제11권6호
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• pp.159-168
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• 2007

장대레일에 발생되는 축력은 좌굴 혹은 파단 등과 같은 사고의 예방에 있어서 매우 중요한 요소이므로 많은 철도 기술자들은 장대레일에 발생되는 축력 산정에 많은 관심을 나타내고 있다. 본 논문에서는 장대레일에 발생되는 축력을 추정하기 위한 보-기둥 이론의 적용성을 고찰하였으며 축력을 추정하는 방정식과 모델의 개발 과정을 제안하였다.

• 한국도시철도학회논문집
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• 제6권4호
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• pp.383-392
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• 2018

본 연구에서는 비교적 경간이 긴 트러스교를 포함한 무도상 교량을 대상으로 장대레일을 부설할 때 궤도-교량 상호작용으로 인한 레일 부가 축응력과 교량 지점 반력 등의 변화를 검토하여 레일 장대화를 위한 개량 방안을 분석하였다. 연구결과에 따르면 무도상 교량에서 장대레일을 부설할 경우 레일 부가 축응력과 지점 반력이 큰 폭으로 증가하는 것으로 나타났다. 레일 부가 축응력은 횡저항력을 충분히 확보할 경우 수용 가능하지만, 지점 반력이 증가하게 될 경우 받침이나 교각의 손상이 우려되고 대규모 보수 보강을 필요로 하므로 지점 반력을 완화시킬 수 있는 방안을 강구할 필요가 있다. 교량 가동단의 마찰저항을 고려하는 경우 레일 부가 축응력은 감소하지만 지점 반력에 미치는 영향은 매우 작은 것으로 나타났다. 반면 궤도 종저항력이 작아지면 레일 부가 축응력과 지점 반력이 모두 큰 폭으로 감소하는 것으로 나타났으며, 레일 부가 축응력이 큰 일부 구간에 ZLR 체결장치를 적용하는 경우 레일 부가 축응력 뿐 아니라 교량 지점 반력이 크게 감소하는 것으로 나타났다. 따라서 무도상 교량의 레일 장대화를 위하여 일부 ZLR 체결장치를 적용하고 궤도 종저항력을 줄이는 방안이 매우 효과적이라고 판단된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.1275-1276
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• 2012

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.386-394
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• 2007

Due to the transportability problems, long rail shall be from base rail unit, which is normally 100m for regular rail and 300m for high speed rail. After these rail units are transported from the fabricator to the site, the field weld would be performed.axial stresses in the long rail is mainly from the temperature differences at various locations the long rail. Also the gaps between each welds cause secondary axial stresses in the rail. In addition to these, re-welds the fractured rails, rail buckling, irregular rail vibration, rail twist also result innonuniform axial stresses in the rail. To obtain the rail buckling stability, the rail stresses shall be released due to the resetting of CWR. Traditionally two resetting of CWR methods have been applied, the one is rail heater and the other is rail tenser. these methods, the latter has been recommended because it has less limitation in the rail length and it is easier to minimized the force differences. But even in this method, the calculation is cumbersome and is not easy to find out the rail stress distribution itself.refined methodsxial stress resetting in the long rail is studied and this study be easily applied in the real construction. From this approach, more rational rail maintenance system can be expected.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1439-1449
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• 2007

The challenging aspect of CWR (continuous welded rail) is the additional axial forces in rails, mainly due to the thermal expansion of steel plate girder and rail itself. It has been found that these axial forces are proportional to girder length, total bridge length and bolt tightening forces. Also these forces are dependent to girder support conditions, types of bearings and their arrangements. With CWR, the authors' previous studies show that performance improvements like noise reduce, fatigue resistances and bearing durability increment can be expected. In addition to these effects, secondary effects due to the semi integral behavior between rail and bridge girder also can be expected. Special bearings which can reduce the absolute maximum axial forces have been developed, and applied to real 100m span bridge. The performance improvements were verified through site measurements and numerical analysis. The purpose of this study is to confirm the expected performance improvement aspects of steel plate girder bridges with CWR. To verify these aspects, girder stiffness changes, rail axial force changes, girder displacements and noise level were thoroughly measured and compared.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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• pp.385-390
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• 2003

Recently, use of Continuous Welded rail(CWR) is increased for structural, economical reason but new problem is caused accordingly and phenomenon that give threat in traveling by ship stability of train is led. According as rail is prolonged, excessive relative displacement and longitudinal force can happen to rail by temperature change and external force. Specially, buckling or fracture of rail can happen in railroad bridges because relative displacement by bridge and properties of matter difference between rail grows and additional axial force happens to rail by behavior of bridge. According to several study, longitudinal force of rail in bridge is influenced with ballast resistance, elongation length, boundary condition, stiffness of framework. Non-linear behavior of ballast acts by the most important factor in interaction between rail and bridge. Therefore, must consider stiffness of bridge construction with non-linear characteristic of ballast and stiffness of base for accuracy with longitudinal force calculation and analyze. In this study, perform material non-linear analysis for longitudinal force of CWR and three dimensional buckling analysis to decide buckling force.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.1306-1311
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• 2006

Most of design parameters of Railway Structures are determined by the serviceability requirements, rather than the structural safety requirements. The serviceability requirements come from Ensuring of Running Safety and Ride Comfort of Train, Reduction of Track Maintenance Work Track-Bridge Interaction should be considered in the design of railway structures. In this study, a numerical method which precisely evaluate an axial force in rail and a rail expansion and contraction when turnout exist in succession on a CWR on a ballasted or on a ballastless track of bridge is developed. From the parameter studies using the developed method, additional stress of stock rail almost 25% is generated due to stock and lead rail interaction, even embankment not bridge. In case of ballasted track, additional stress of stock rail on bridge is very greater than on embankment, and therefore require detailed review in bridge design with turnout. Stresses of turnout rails on bridge are very sensitive according to the installed positions. In case of ballastless track, Stresses of turnout rails are similar as those of normal track