• Journal of the Korean Society for Railway
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• v.16 no.3
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• pp.217-225
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• 2013

In this study, by considering the rail fastening support distance and the distance between the bridge and the abutment, the behavior of concrete track installed on a railway bridge end deck and the bridge end rotation were analyzed. In order to analyze the track-bridge interaction, bridge and abutment specimens with concrete track structures were designed and used in laboratory testing. At a constant fastening support distance, an increase in the bridge end rotation caused an increase in the displacement of the rail. Therefore, the displacement of the rail directly affects the rail and clip stress. Further, it is inferred that the results of multiple regression analysis obtained using measured data such as angle of bridge end rotation and fastening support distance can be used to predict the track-bridge interaction forces acting on concrete track installed on railway bridge deck ends.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1478-1485
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• 2010

In this paper, the nonlinear dynamic response of Vehicle-Bridge interaction with the coupled equations of motion including nonlinear Hertzian contact is presented. The moving train model is chosen to have 10 degrees of freedom (DOF). The bridge is modeled as 2D Euler-Bernoulli beam element with 4 DOF for each element, two for rotations and another two for translations. The nonlinear Hertzian contact is used to simulate the interaction between vehicle and bridge. Base on the relationship of wheel displacement of the vehicle and the vertical displacement of the bridge in Hertzian contact, the coupled equations of motion of the whole system is derived. The convenient formulation was encoded into a computer program. The contact forces, contact area and stress of the rail surface were also computed. The accuracy and efficiency of the proposed program are verified and compared with exact analytical solution and other previous studies. Various numerical examples and parametric studies have demonstrated the versatility and applicability of the proposed program.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1028-1033
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• 2004

The open deck steel bridge is the most common type in railway bridges. Steel I-shaped girders are connected with sleepers directly without ballast and moving train loads are transmitted directly to the girder, so this bridge has weak characteristics on impact. Therefore, considerable accelerations can cause unsatisfactory dynamic behavior of the open deck steel bridge. Especially, Impact created at rail joints can increase the dynamic response of the bridge and this phenomenon would be injurious to passenger comfort. In the present study, dynamic behavior of the open deck steel bridge which has a rail joint is estimated through experimental studies and bridge-train interaction analysis considering surface irregularities by rail joints.

• International journal of steel structures
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• v.18 no.5
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• pp.1617-1630
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• 2018

The crucial differences between conventional rail with split-type connectors and continuous welded rails are axial stress in the longitudinal direction and stability, as well as other issues generated under the influence of loading effects. Longitudinal stresses generated in continuously welded rails on railway bridges are strongly influenced by the nonlinear behavior of the supporting system comprising sleepers and ballasts. Thus, the track structure interaction cannot be neglected. The rail-support system mentioned above has properties of non-uniform material distribution and uncertainty of construction quality. The linear elastic hypothesis therefore cannot correctly evaluate the stress distribution within the rails. The aim of this study is to apply the nonlinear finite element method using the nonlinear coupling interface between the track and structural model and to illustrate the welded rail behavior under the loading effect and uncertain factors of the ballast. Numerical results of nonlinear finite analysis with a three-dimensional solid and frame element model are presented for a typical track-bridge system. A composite plate girder, modeled by solid and shell elements, is also analyzed to consider the behavior of the welded rail. The analysis result showed buckling under the independent calculations of load cases, including 'temperature change', 'bending of the supporting structure', and 'braking' of the railway vehicle. A parametric study of the load combination method and the loading sequence is also included in this analysis.

• Journal of the Korean Society for Railway
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• v.12 no.6
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• pp.974-982
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• 2009

To improve the effectiveness and economics the bridge design methodology considering the bridge/rail longitudinal analysis and bridge/vehicle dynamic effect suggested in this study. The reliability-based Life-Cycle Costs(LCC) effective optimum design is applied to a 2-main steel girder bridge, 5$\times$(1@50m) for comparison with conventional design, initial cost optimization and equivalent LCC optimization. As a result of the optimum design based on reliability, it may be stated that the design of High-Speed railway bridges considering the bridge/rail longitudinal analysis and bridge/vehicle dynamic effect are more efficient than typical existing bridges and LCC optimization without respect to bridge/rail longitudinal analysis and bridge/vehicle dynamic effect. The result of optimization design considering the interaction, design methodology suggested in this study, is higher than result of initial cost optimization design in initial cost, but that has the advantage than result of initial cost optimization design in expected LCC.

• Journal of the Korean Society for Railway
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• v.19 no.5
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• pp.638-646
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• 2016

CWR (continuous welded rail) tracks on high-speed railway bridges have much more complicated axial force distributions caused by track-bridge interaction than those behaviors on embankments, and additional problems caused by track-structure interaction with the axial force of the CWR. In order to analyze and limit other physical phenomena caused by track-bridge interaction, a design guideline (KR C-08080, longitudinal track-bridge interaction analysis) is used when designing CWR track on bridges. Domestic analysis and design methods for track-bridge interaction follow the UIC 774-3R, and they suggest conservative methods and deterministic properties. Recently, many studies analyzing the methods of track-bridge interaction considering the loading history are being carried out; however, there has been insufficient studies of the variation of the resistance properties with a consideration of the actual loading history. In this study, the performances of rail fastening systems used for concrete track on bridges were tested and analyzed while considering the loading history. For this purpose, longitudinal and vertical loading combinations, applied in order to simulate the practical conditions and resistance characteristics (stiffness and elastic limit displacement), are analyzed through the experimental results. Also, a comparison study was conducted with the properties in the KR Code.

• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.1015-1021
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• 2001

This paper represents the results carried out to determine the dynamic response characteristics of Korea High Speed Rail(KHSR) bridges. The responses of the KHSR bridges subjected to the moving train loading are obtained through the simplified method for the 2-dimensional train/track/bridge interaction analysis in which the eccentricity of axle loads and the effect of the torsional forces acting on the bridge are included for the more accurate train/track/bridge interaction analysis. The results of the analyses are compared with the field test data to verify the performance of the 2-dimensional train/track/bridge interaction analysis method.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.366-373
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• 2000

This paper represents the results carried out to determine the dynamic response characteristics of Korea High Speed Rail(KHSR) bridges. The responses of the KHSR bridges subjected to the moving train loading are obtained through the simplified method for the 2-dimensional train/track/bridge interaction analysis in which the eccentricity of axle loads and the effect of the torsional forces acting on the bridge are included for the more accurate train/track/bridge interaction analysis. The results of the analyses are compared with the field test data to verify the performance of the 2-dimensional train/track/bridge interaction analysis method.

• Journal of the Korean Society for Railway
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• v.18 no.4
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• pp.363-373
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• 2015

The purpose of this study is to develop a nonlinear algorithm for the dynamic interaction analysis of KTX trains and bridge girders with consideration of separation and flange contact phenomena between wheel and rail. For this, three interaction models between wheel-rail are implemented and compared through numerical examples. That is, the spring model and the non-jump model are briefly explained, and a nonlinear contact model is then proposed to accurately simulate interaction forces of the train-bridge system. Dynamic interaction analysis of a simply supported girder and trains is performed and the analyzed results are presented and compared for the proposed contact model and the other model types. Particularly, flange contact phenomena in the nonlinear contact model are demonstrated under a specific condition.