• Title/Summary/Keyword: 부가축력

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Development of Design Chart for Investigating an Additional Rail Stress and Displacement on CWR(II) - Design Chart for Railway Bridge of Conventional Line (장대레일 부가축력 및 변위 검토를 위한 설계차트 개발(II) - 일반철도 교량 설계차트)

  • Choi, Il-Yoon;Lim, Yun-Sik;Yang, Sin-Chu;Choi, Jin-Yu
    • Journal of the Korean Society for Railway
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    • v.12 no.4
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    • pp.574-581
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    • 2009
  • Displacement of the bridge and additional rail stress due to interaction between track and bridge should be limited to the design criteria. Interaction analysis was conducted to investigate the displacement and additional rail stress on CWR in railway bridge of conventional line. Particularly, various parameters affecting interaction phenomena were taken into account in the analysis to enhance an applicability. These parameters included configuration of structure, stiffness of deck and support, steel/concrete bridge, ballast/concrete track and FM/MFM type etc. The results were presented in the form of the design chart which could be useful in preliminary design of the bridge.

Development of Design Chart for Investigating an Additional Rail Stress and Displacement on CWR(I) - Design Chart for High Speed Railway Bridge (장대레일 부가축력 및 변위 검토를 위한 설계차트 개발(I) - 고속철도 교량 설계차트)

  • Choi, Il-Yoon;Cho, Hyun-Cheol;Yang, Sin-Chu;Choi, Jin-Yu;Yu, Jin-Young
    • Journal of the Korean Society for Railway
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    • v.12 no.4
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    • pp.565-573
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    • 2009
  • Displacement of the bridge and additional rail stress due to interaction between track and bridge should be limited to the design criteria. Interaction analysis was conducted to investigate the displacement and additional rail stress on CWR in high speed railway bridge. Particularly, various parameters affecting interaction phenomena were taken into account in the analysis to enhance an applicability. These parameters included configuration of structure, stiffness of deck and support, steel/concrete bridge, ballast/concrete track and FM/MFM type etc. The results were presented in the form of the design chart which could be useful in preliminary design of the bridge.

An Experimental Study on the Fatigue Behavior of T-Type Tension Joints with High Tension Bolt (고장력볼트 T-인장이음의 피로거동에 관한 실험적 연구)

  • Lee, Seung Yong;Choi, Jun Hyeok
    • Journal of Korean Society of Steel Construction
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    • v.28 no.6
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    • pp.459-465
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    • 2016
  • In this paper, it was performed the fatigue test to examine the effect of cyclic loading for the simple T-joint. Axial force of bolt by clamping and the change of the force by applied load were measured in the joint. And the bolt force, the failure mode and the fatigue strength under cyclic loading were investigated. The parameters of the tension joint were set to be the flange thickness and the diameter of bolt to a different stiffness of the joint in response to the combination. From the fatigue test, failure mode of tensile joints under cyclic loading could be evaluated using a static ultimate load of the specific failure mode in EC3. The fatigue strength of the tension joints was considerably higher than the fatigue strength of the EC3(36) that does not consider a lever action. However, the additional axial force by lever action occurs to an increase in the axial force of the bolt it requires a careful evaluation of the fatigue strength.

Comparative Analysis of Track-Bridge Interaction of Sliding Slab Track and Rail Expansion Joint for Long-Span Railway Bridge (장경간 철도 교량에 적용된 슬라이딩 궤도와 레일신축이음장치의 궤도-교량 상호작용 비교)

  • Lee, Kyoung Chan;Jang, Seung Yup;Lee, Jungwhee;Choi, Hyun Sung
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.29 no.2
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    • pp.169-177
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    • 2016
  • Sliding slab track system, which consists of low friction sliding layer between track slab and bridge deck, is recently devised to reduce track-bridge interaction effect of continuously welded rail(CWR) without applying special devices such as rail expansion joint(REJ). In this study, a series of track-bridge interaction analyses of a long-span bridge with sliding slab track and REJ are performed respectively and the results are compared. The bridge model includes PSC box girder bridge with 9 continuous spans, and steel-concrete composite girder bridge with 2 continuous spans. The total length of the bridge model is 1,205m, and the maximum spacing between the two fixed supports is 825m. Analyses results showed that the sliding slab track system is highly effective on interaction reduction since lower rail additional axial stress is resulted than REJ application. Additionally, horizontal reaction forces in fixed supports were also reduced compared to the results of REJ application. However, higher slab axial forces were developed in the sliding slab track due to the temperature load. Therefore, track slab section of the sliding slab track system should be carefully designed against slab axial forces.

Statistical Characteristics for Longitudinal Friction Behavior of Rail Fastening System for Concrete Track (콘크리트 궤도용 레일체결장치의 종방향 마찰거동에 대한 통계적 특성)

  • Bae, Hyun-Ung;Park, Sang-Jun;Yun, Kyung-Min;Park, Beom-Ho;Lim, Nam-Hyoung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.11
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    • pp.7870-7877
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    • 2015
  • In the case of CWR (Continuous welded rail) located on the railway bridge, the CWR has additional axial force due to interaction of bridge and track. Therefore, the CWR tracks located on the bridge have to secure the safety of running train and CWR track through mitigating influence for interaction of bridge and track. The railway design guide in Korea (KR C-08080) provides a certain value for property of longitudinal friction behavior of rail fastening system that is major parameter of interaction behavior by applying European codes. However, in order to apply to domestic railway, it is necessary to review property characteristics of the rail fastening system in actual use. In this paper, the experiment for longitudinal friction behavior of rail fastener applied to concrete track on the railway bridge in Korea was carried out, and statistical characteristic for property of the rail fastener was analyzed from the result of the experiment.

Case Study of the Characteristic of Ground Deformation and the Strut Axial Force Change in Long Span Deep Excavation (장지간 깊은 굴착에서 지반변형 및 버팀보 축력변화 특성 사례 연구)

  • Kim, Sung-Wook;Han, Byung-Won
    • Journal of the Korean Geotechnical Society
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    • v.26 no.7
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    • pp.171-186
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    • 2010
  • It is generally known that the mechanism of behavior in the flexible earth retaining system is relatively more complicated than in the rigid earth retaining system. Moreover in the case of long span strut supporting system the analysis of strut axial force change becomes more difficult when the differences of ground condition and excavation work progress on both sides of excavation section are added. When deeper excavation than the specification or installation delay of supporting system or change of ground condition happen during construction process, lots of axial force can be induced in some struts, which threaten the safety of construction. This paper introduces two examples of long span deep excavation where struts and rock bolts were used as a supporting system with flexible wall structure. The characteristics of ground deformation and strut axial force change, which were measured in the sections of two examples that are 50 meters apart in one construction site and have almost similar design and construction conditions were analysed, the similarity and difference between measurement results of two examples were compared and investigated. This article aims to improve and develop the technique of design and construction in future projects having similar ground condition and supporting method.

크리프와 건조수축을 고려한 철근콘크리트 기둥과 동바리의 축력 재분배 해석법

  • 김선영;이태규;김진근;이수곤
    • Journal of the Korea Concrete Institute
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    • v.13 no.6
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    • pp.629-636
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    • 2001
  • To apply the research results to the design and the construction of the high rise buildings, long-term behavior of reinforced concrete structure have been widely studied. However, shoring and reshoring at early ages have not been considered in the most of studies. The removal of forms and shores has been dealt with one construction sequence. i.e. the deformation occurred at the early age before the removal of shore has been neglected. In this paper, two-dimensional frame analysis program for long-term behavior of reinforced concrete was developed. In the developed program, construction sequence including the settlement and the removal of shores is considered to predict axial force variation due to forms ,shores, and time-dependent concrete stiffness. Analysis results show that the time-dependent axial force of shores is reduced, and the redistributed axial force of the interior column is greater than the value by elastic analysis and that of the exterior column is smaller. In order to demonstrate the validity of this program, the test frame was constructed in sequence of the placement of concrete, form removal, reshoring, shore removal, and the application of additional load. The proposed program predicts experimental results well.

Evaluation of Stress Reduction of Continuous Welded Rail of Sliding Slab Track from Track-Bridge Interaction Analysis (궤도-교량 상호작용 해석에 의한 슬라이딩 슬래브 궤도의 장대레일 응력 저감 효과 분석)

  • Lee, Kyoung Chan;Jang, Seung Yup;Jung, Dong-Ki;Byun, Hyung-Kyoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.5
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    • pp.1179-1189
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    • 2015
  • Continuous welded rail on bridge structure experiences typically a large amount of additional longitudinal axial forces due to longitudinal track-bridge interaction under temperature and traction/braking load effect. In order to reduce the additional axial forces, special type of fastener, such as ZLR and RLR or rail expansion joint should be applied. Sliding slab track system is known to reduce the effect of track-bridge interaction by the application of a sliding layer between slab track and bridge structure. This study presents track-bridge interaction analysis results of the sliding slab track and compares them with conventional fixed slab track on bridges. The result shows that the sliding slab track can significantly reduce the additional axil forces of the continuously welded rail, and the difference is more significant for long and continuous span bridge.

Application of a Fictitious Axial Force Factor to Determine Elastic and Inelastic Effective Lengths for Column Members of Steel Frames (강프레임 기둥 부재의 탄성 및 비탄성 유효좌굴길이 산정을 위한 가상축력계수의 적용)

  • Choi, Dong Ho;Yoo, Hoon;Lee, Yoon Seok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.2A
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    • pp.81-92
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    • 2010
  • In design of steel frames, it is generally believed that elastic system buckling analysis cannot predict real behaviors of structures, while inelastic system buckling analysis can give informative buckling behaviors of individual members considering inelastic material behavior. However, the use of Euler buckling equation with these system buckling analyses have the inherent problem that the methods evaluate unexpectedly large effective lengths of members having relatively small axial forces. This paper proposes a new method of obtaining elastic and inelastic effective lengths of all members in steel frames. Considering a fictitious axial force factor for each story of frames, the proposed method determines the effective lengths using the inelastic stiffness reduction factor and the iterative eigenvalue analysis. In order to verify the validity of the proposed method, the effective lengths of example frames by the proposed method were compared to those of previously established methods. As a result, the proposed method gives reasonable effective lengths of all members in steel frames. The effect of inelastic material behavior on the effective lengths of members was also discussed.

Equivalent Plastic Hinge Length Model for Flexure-Governed RC Shear Walls (휨 항복형 철근콘크리트 전단벽의 등가소성힌지길이 모델)

  • Mun, Ju-Hyun;Yang, Keun-Hyeok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.2
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    • pp.1-8
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    • 2014
  • The present study proposes a simple equation to straightforwardly determine the potential plastic hinge length in boundary element of reinforced concrete shear walls. From the idealized curvature distribution along the shear wall length, a basic formula was derived as a function of yielding moment, maximum moment, and additional moment owing to diagonal tensile crack. Yielding moment and maximum moment capacities of shear wall were calculated on the basis of compatability of strain and equilibrium equation of internal forces. The development of a diagonal tensile crack at web was examined from the shear transfer capacity of concrete specified in ACI 318-11 provision and then the additional moment was calculated using the truss mechanism along the crack proposed by Park and Paulay. The moment capacities were simplified from an extensive parametric study; as a result, the equivalent plastic hinge length of shear walls could be formulated using indices of longitudinal tensile reinforcement at the boundary element, vertical reinforcement at web, and applied axial load. The proposed equation predicted accurately the measured plastic hinge length, providing that the mean and standard deviation of ratios between predictions and experiments are 1.019 and 0.102, respectively.