• 한국안전학회지
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• 제25권5호
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• pp.54-61
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• 2010

The additional axial force of CWR(continuous welded rail) is occurred by structure-track interaction, in reverse, fixed supports of structure are applied the large load by that. Ratio of load which transferred on support through the bridge superstructure with one-side REJ by acceleration and braking load are stated in High-Speed Rail Design Criteria(2005). On the other hand the horizontal forces of support delivered to the load due to thermal loads has been no report about the criteria. Therefore, this study was performed the review of the reaction and displacement on support by structure-track interaction in a special bridge(composite brdiges, 45+55+55+45=200m) with REJ acting on the temperature load. As a result, because fixed support of a special bridge or a continuous bridge with REJ under the temperature load which is constant load has been acted the large lateral load by structure-track interaction, when determining the fixed bearing capacity of structure should be reflected in the results to secure the safety of structures was confirmed.

• 한국철도학회논문집
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• 제12권6호
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• pp.974-982
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• 2009

본 연구는 교량/궤도 종방향 해석 및 교량/차량 동적영향을 고려한 설계기법에 대한 효율성 및 경제성을 증명하기 위하여 수행하였다. 신뢰성에 기초한 생애주기비용 최적설계는 기존 설계기법에 의한 설계, 초기비용에 기초한 최적설계, 등가 생애주기비용 최적설계에 의한 최적설계와 비교하기 위하여 5$\times$(1@50m) 경간 소수주형 교량을 대상으로 적용하였다. 신뢰성에 기초한 최적설계 결과 교량/궤도 종방향 해석 및 교량/차량 동적영향을 고려한 고속철도 교량 설계 단면이 교량/궤도 종방향 해석 및 교량/차량 동적영향을 고려하지 않은 설계 단면보다 훨씬 효율적임을 확인 하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2487-2492
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• 2011

At high rail temperature above the neutral temperature, high compressive axial stresses will occur in the rails. High thermal axial force and vehicle loads cause the track to shift in a lateral direction and the formation of track geometry imperfections (track irregularity). When the thermal stress level and track irregularity with vehicle load reach a critical value, the track loses stability. In many studies, the stability of CWR tracks is analyzed. However these studies are only considered in temperature load. The main objective of this investigation was to estimate a new, comprehensive, realistic, the stability of CWR tracks considering wheel load. The ballast resistance is changed by wheel load. When the wheel load is applied, rails and ties are moved upward or downward. In this case the friction between ties and ballasts is decreased or increased. In this study the change of the ballast resistance of each tie was applied to the nonlinear analysis of CWR tracks.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.303-306
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• 2007

CWR(Continuous Welded Rail) and bridge interaction produce rail force, bridge displacement and rail/bridge relative displacement. Each of these has limitation by many codes. In this paper, analysis of interaction has been carried out by using foreign codes(UIC 774-3 R code of Europe etc.) because there is no code about interaction between rail and bridge in Korea. Recently, railway bridges with CWR has been constructed for structural and economical reasons. When designer plans railway bridges, design a bridge model first and then investigate railway forces and displacement by interaction analysis. If these results go out bounds from limitation, designer plans railway bridges again and again. In this paper, using the parametric study on CWR and railway bridge interaction, railway bridge parameters such as length of bridge span, area of bridge, moment of inertia, stiffness of pier, etc. are presented. It helps preliminary design of railway bridges.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.305-309
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• 2010

The buckling behavior of CWR tracks is affected by the various parameters such as stiffness and geometry of track panel, ballast resistance, rail temperature, initial imperfection, and wheel load. Until now, CWR tracks were managed by the dichotomous logic (deterministic approach) despite these influence factors are having the nature of random variables. So, the design method and existing management process to prevent the track buckling can be very non-economic since the value of these influence factors to calculate the track buckling strength are selected by considering the worst track condition. In this study, buckling probability evaluation process is proposed which is based on the reliability index, AFOSM method, and limit state equation.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.401-410
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• 2007

Form the application of long rail system the non-ballast steel plate bridges, fatigue strength increase and rail noise reduction can be expected. This is mainly form the reduction of the rail impact at the rail joint locations which already made to behave together from welds. In the high speed rail, application of long rail system is essential because without long rail system, the required serviceability level can not be achieved. But even with this long rail systems, the thermal expansion from the girder can not be absorbed in the normal bearing systems, and these expansion cause between girder and rail. Also unexpected rail buckling and fracture through rail thermal tension may happen. It was found through numerical analysis and field measurement that these problems can be avoided by semi-fixed bearing system. In this study, the benefits of non-ballast plate bridge through long rail system, especially at the point of girder stability, girder stiffness increase and bearing maintenance will be reviewed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.99-105
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• 2009

This research presents the method to decide proper locations for destressing of CWR using a non-destructive equipments to measure the longitudinal force(installation temperature) in CWR. The effect and necessity of destressing were analyzed by estimating changes of longitudinal force. The installation temperature was measured to find changes of longitudinal force in high speed and conventional lines before and after destressing or track maintenance at the locations where destressing was planed or where change of longitudinal force was expected during track maintenance. Past destressing was carried out within qualitative decision criteria. This research proposes the quantitative criteria to decide the priority order of the destressing locations reasonably by considering the difference of air temperature and stress free temperature during the track maintenances, the grade of ballast resistance force recovering and the length of destressing, etc.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.781-787
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• 2004

Where the track is continuously welded over a bridge, the longitudinal force is interacted between the track and the sub-structure. Due to this respect, the expansion joint is used to decrease this force. But the expansion joint has several problems related to passenger comfort and maintenance etc. In this study, it is analysed about how the stability of the track is affected as the span length becomes longer in case of 2-span continuos bridge. It is found that there is no problem of an stability unless the span length is longer than 90m when the elastic shoe is used. And several parametric studies were also implemented.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.426-436
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• 2006

The use of the CWR track has increased consistently in the worldwide. Because the use of CWR track not only reduces the track maintenance cost, noise and vibration, but increases the life cycle of track components. Therefore, to increase train speed, improve riding condition and secure running stability, the necessity of study on making CWR is increasing. This study includes the development of a thermal buckling theory in the evaluation of curved track stability. The lateral stability of curved CWR is studied for track buckling prevention through the parameter studies. It studied the lateral buckling of the curved CWR track on the 3-D nonlinear analysis. The parameters include rail size, cant, track curvature.

• 한국방재학회 논문집
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• 제10권6호
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• pp.27-34
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• 2010

최근 친환경 운송수단인 고속철도에 대한 관심이 증가하고 있으며, 그에 따른 고속철도 교량이 많이 건설되고 있다. 하지만 기존의 일반 철도 교량에 비해 고속철도 교량은 고속주행하는 열차의 동적 하중에 의한 영향이 증가하게 되므로, 이에 대한 고려가 필요한 실정이다. 따라서 본 연구에서는 고속주행하는 열차의 주행 안정성을 확보하기 위해 고속철도 교량의 구조물-궤도 상호작용 및 동적 안전성을 동시에 고려하여 설계하는 방법을 제안하였고, 제안한 알고리즘의 효율성을 입증하기 위하여 기존의 재래식 설계에 의하여 설계, 시공되어진 단순 5경간 250 m 교량을 대상으로 수치해석을 수행하여 비교하였다. 수치해석 결과, 교량-궤도 상호작용 및 교량-차량 상호작용을 동시에 고려한 최적설계가 기존의 제안된 여러 설계 방법들과 비교했을 때, 최적화의 목적함수로 설정한 생애주기비용이 가장 경제적임을 확인하였다.