• Title, Summary, Keyword: CWR

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The characteristics of buckling of the CWR with respect to the ballast behaviour (도상 저항력 거동을 고려한 장대레일의 좌굴 특성)

  • Kim Hyun-June;Lee Bang-Woo;Sim Hyun-Woo
    • Proceedings of the KSR Conference
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    • pp.82-90
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    • 2003
  • The advance in technology of the CWR in Korea has led the establishment of the CWR on the sharp curve (i.e. less than R=600m). As thermit welding used in the sharp-curved construction site is carried out on the curve track, it is difficult to adjust a curve shape accurately and these difficulties have occurred in a number of cases. Therefore, in this study, the lateral buckling analysis of CWR track was carried out considering the actual ballast resistance force. In addition, the cant and vertical resistance force in ballast was considered in order to predict the initial behaviour of bucking in track under the more accurate method.

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Longitudinal Force Analysis of CWR on High Speed Rail Bridges (고속철도 교량상의 장대레일 축력 해석)

  • 이지하;양신추;이종득
    • Proceedings of the KSR Conference
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    • pp.556-563
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    • 1998
  • Railway bridges have a significant effect on the stress and displacement of continuous welded rail(CWR). Longitudinal compression force at high temperature, combined breaking or acceleration forces can introduce track buckling. On the other hand, longitudinal tensile forces, associated with low temperatures, in combination with breaking forces may break rail. Therefore, it is very important to work out thorough counter measures for those problems, specially in high speed rail which high safety is required. The exact evaluation of longitudinal force of rail has the key to the solution. The main aim of the present paper is to examine whether the longitudinal force of CWR's on Kyung-Bu-HSR satisfy the criteria to be fulfilled in the design of railway bridge. The analyses are carried out by using "CWRAP" program which was developed by our research group. The ballast resistance and breaking force effects on the longitudinal force of CWR are investigated.

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CWR for Seoul Subway No 2 DangSan Bridge by ZLR (Zero Longitudinal Restraint) (종방향 활동체결구를 사용한 당산철교 장대레일화 사례)

  • Lee Duck Young;Kong Sun Yong;Kwon Soon Sub;Kim Eun
    • Proceedings of the KSR Conference
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    • pp.379-384
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    • 2003
  • DangSan Bridge of Seoul Subway No 2 was rebuilt by safety reason. From Dec 1996 to Dec 1999 we were in charge of permanent way design of this rebuilt project. Especially we applied maintenance free system on the bridge by Cologne Egg alternative (ALT1) base plate and CWR (Continuous Welded Rail) by ZLR(Zero Longitudinal Restraint) for 125m (south approach section), 120m long(north approach section). This thesis generally introduce for CWR by ZLR which was first adapted CWR system in Korea.

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Analysis of CWR Track Considering Wheel Loads (열차하중을 고려한 장대레일 궤도 해석)

  • Han, Sang-Yun;Kang, Young-Jong;Han, Teak-Hee;Lim, Nam-Hyoung;Kim, Jung-Hun
    • Proceedings of the KSR Conference
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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.

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CWR for Young Jong Great Bridge Sourth Approach Section by ZLR (Zero Longitudinal Restraint) (종방향 활동체결구를 이용한 영종대교 남측 접속교량의 장대레일화 사례)

  • Lee Duck Young;Yang Sin Chu;Kwon Soon Sub;Kim Yong Man
    • Proceedings of the KSR Conference
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    • pp.1057-1064
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    • 2004
  • For New In-Cheon Airport. South Approach Section of Young long Great Bridge is to be special concerned to CWR due to substructure was already constructed former railroad bridge design specification. So we applied maintenance free system and CWR (Continuous Welded Rail) by ZLR(Zero Longitudinal Restraint) at bridge expansion joint part. This thesis generally introduce for CWR by ZLR at South Approach Section of Young long Great Bridge.

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A Study on the Sensitivity of Influencing Parameters on Axial Force in CWR on a Viaduct (교량상 장대레일의 축력 영향인자의 민감도 분석에 관한 연구)

  • Chun, Hee-Kwang;Choi, Jin-Yu;Choi, Il-Yun;Yang, Shin-Chu;Jeong, Jang-Yong
    • Proceedings of the KSR Conference
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    • pp.1043-1049
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    • 2008
  • Trouble by excessive axial stress in CWR layed on a bridge is frequently happen, and this problem is induced from lack of considering on the track/structure interface on preliminary design stage. In this study, the sensitivity evaluation for the major influencing parameters, that is, expansion length of span, stiffness of super structure, arrangement of bearing, and strength of sub-structure, to the axial force in CWR on a bridge is conducted. From the sensitivity study, the guideline to reduce axial force efficiently in CWR for bridge engineer was suggested. The suggested guideline may not applicable for every case, but it is helpful for preliminary design of bridge.

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Parametric study on Continuous Welded Rail and Bridge interaction (장대레일 궤도와 교량의 상호작용에 대한 매개변수 분석)

  • Kim, Jong-Min;Han, Sang-Yun;Lim, Nam-Hyoung;Kang, Young-Jong
    • 한국방재학회:학술대회논문집
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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.

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Estimation of Bending Fatigue Life of CWR in Concrete Track (콘크리트궤도 장대레일의 휨 피로수명 평가)

  • Sung, Deok-Yong;Tae, Sung-Sik;Park, Kwang-Hwa;Kong, Sun-Yong;Park, Yong-Gul
    • Proceedings of the KSR Conference
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    • pp.64-71
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    • 2010
  • It is suggested that the service life of the continuous welded rail(CWR) is estimated by the relationship between the rail surface irregularity according to the accumulated passing tonnage and bending fatigue of welded part in CWR. In this study, based on the results of bending fatigue tests of rail and results of measuring tests in situ of rail bending stress, this study estimated the bending fatigue life of welded rail in concrete track, adopting a Haibach's rule. The bending fatigue life of CWR considered the rail surface irregularity, train speed and the S-N curve by types of rail welding. In addition, this study estimated it for the fracture probability 1%, 0.1%, 0.01%. Therefore, this study proposed bending fatigue life of CWR in concrete track.

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Stability Analysis for CWR on the Railway Bridges by Linearized Method (선형해석법을 이용한 교량상 장대레일의 안정성 해석 방법 연구)

  • Choi, Young-Gil;Oh, Ju-Won
    • Journal of the Korean Society for Railway
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    • v.12 no.4
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    • pp.472-480
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    • 2009
  • The stability analysis for CWR is difficult in the theory itself because both geometric and material nonlinearity should be considered. Also the analysis results are varied according to the loading history. In contrast to the complexity in the theory, the analysis results for CWR on the railway bridges are quite simple and can be predicted because of a small buckling effect and its negligible nonlinearity. In this study, refined nonlinear analysis methods for the stability analysis of CWR on the railway bridges were developed which consider only material nonlinearity beeause the effects of geometric nonlinearity are nominal. In this study, the analysis results can be found within limited number of iterations with idealized linear force-displacement relationship. From the analysis result comparisons, it was found that the stability analysis for CWR on the railway bridges can be performed effectively by this method.