• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.4
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• pp.391-400
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• 2004

Railway curved zone have crucial effects on the speed of train. Length of transition curve is one of the important factor for alignment compatibility estimation in this sections, this value is decided by running speed and Cant. In this study, the extension method of transition curve is evaluated, based on the alignment of Jang Hang-Line, investigated field conditions of the sections in the curves exist. This research result show that changing of transition curve was proved by necessary to approximately two thirds of the curved sections, and method of fixing central point of track centerline and changing radius of curvature minimize the maximum shift in track centerline and deviation of radius, and also may be effective method for alignment suitability and speed up in case overall improvement is difficult.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.173-180
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• 2008

The major objective of this study is to proposal of measuring method and design for the testing curved railway in which the tilting train runs. In order to the speed-up of conventional lines that have many curve lines, there needs a improvement construction of substructure such as the straight or double track work and so on. But in this case, it needs to have a plenty of the cost and the period. Therefore, the tilting train which provides the high-speed service effectively in curve tracks was developed. Besides, the efficiency prediction and the linear synthesis of the existing conventional line for a tiling train service were examined on the preceding studies. So, in this paper we propose the measuring plan and the design of the improvement sections in the testing curved track which was decided as a results of material analysis and field research concerning the extension possibility of transition curves and the bearing of track due to the new developed train traveling. And we look forward to playing a decisive role as reference data on the improvement construction project for the commercial service of the tilting train.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.157-162
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• 2003

The curved line in construction of railroad is inevitable. Also it needs a transition curve when the straight line connects to curved line. In this research, by establishing the reciprocal relations of inner, center and outer track, we will present the calculation method of construction-center line in normal double-track railroad which uses cubic parabolic type as a transition curve.

• Proceedings of the KSR Conference
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• 1999.05a
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• pp.428-433
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• 1999

In this study, new finite clement formulations are carried out to analyze the distortion of the curved steel box girders which are susceptible to the torsional loading. For the exact analysis of curved box girders, additional degrees of freedom are added besides the conventional 6 degrees of freedom of general-purpose finite analysis programs, which are torsional warping, distortional warring, and distortion. New formulations were coded into a computer programs. Several numerical examples were presented to demonstrate the validity of developed program.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.309-314
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• 2003

A vertical curve should be installed in straight section. In case, it be installed on horizontal curved section, safety factor go down. In this study, it is calculated that the deficiency of cant about vertical curve radius on horizontal curved section. The result of this study will be used on planning the tack layout of railroad and design the track construction.

• International Journal of Railway
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• v.5 no.2
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• pp.93-101
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• 2012

Owing to the lightening of railway vehicles and increased operation speeds, the reduction of running safety in the presence of crosswind is becoming an important problem. In particular, the running safety tends to decrease when vehicles run on curved track. When a crosswind acts on a vehicle negotiating a curve from the outer side, flange climbing can occur. In this study, a full-vehicle model was constructed using the multi-body simulation software SIMPACK, and a simulation of a bogie vehicle with two-axle trucks negotiating a curve was carried out to examine the running safety under the condition where a crosswind acts on the vehicle from the outer side of the curve. As a result, it was verified that the derailment coefficient of the first wheelset becomes large in the exit transition curve and the coefficient of the third wheelset does in the entrance transition curve, and this trend becomes pronounced at low operation speeds in the presence of a stronger crosswind. It was also shown that the critical derailment coefficients obtained by modified Nadal's formula considering the effect of attack angle become close to the actual derailment coefficients at the timing that flange climbing occurs.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.9
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• pp.759-764
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• 2014

Lateral force of wheel is important parameter when we evaluate the safety of a railway vehicle on curved track. The lateral force of wheel is influenced by the steering performance of wheelsets. Generally, in passive type vehicles, the steering performance of wheelsets is influenced by the parameters like primary spring stiffness, wheel base, conicity of the wheel profile, etc. But, the steering performance of passive type vehicle has its limit. To overcome the limit of the steering performance of passive type vehicle, active steering technology is being developed. In this paper, we analyze the lateral force of wheel and the safety of the railway vehicle on curved track by adopting the active steering technology. As results of dynamic analysis for vehicle model equipped with active steering system, the lateral force of wheel is reduced and the safety is improved remarkably.

• Proceedings of the KSR Conference
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• 2001.05a
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• pp.289-294
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• 2001

A curved track needs balanced super elevation according to the speed of the passing train and it is limited by maximum allowable amount. Therefore, passing speed at high degree curved track has to be controlled below the limits. Accurate position of the Speed Limit Post(SLP), which shows allowable speed of curved track dose not regulated so design and line side maintenance engineer adopt the position differently, When the rate of cant deficiency is considered on transition-curved section, the SLP should be located at the beginning point of the transition curve so as to control the speed of passing train and it will increase ride quality to passenger.

• Journal of the Korean Society of Safety
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• v.32 no.4
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• pp.28-33
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• 2017

A sharp curved ballasted track on earthwork that was connected with a direct fixation slab track on steel box railway bridges have been deformed and damaged despite the frequently maintenance by a restoring force of sharp curved rail and track-bridge interaction forces such as axial forces and longitudinal displacement of continuous welded rail(CWR) owing to their structural characteristics, calling for alternatives to improve the structural safety and track irregularity. In this study, the authors aim to prove a cause of deformation for the sharp curved ballasted tracks to enhance the structural safety and track irregularity of ballasted track in service. A track-bridge interaction analysis and a finite-element method analysis for the sharp curved ballasted track were performed to consider the axial force and longitudinal displacement of CWR, the temperature and the effect of restoring force of sharp curved rail. From the results, the deformation of the sharp curved ballasted track with adjusted sleeper spacing from 833mm to 590mm were significantly reduced.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.6
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• pp.547-555
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• 2016

The wheel wear of a railway vehicle is mainly generated when maneuvering on a curved track. The change in the wheel profile affects the dynamic stability of the vehicle. In this analysis, the wheel wear volume was calculated while changing the velocity and radius of the curve to analyze the wear characteristics of a wheel at a curved section. The wear index was calculated from a vehicle dynamic analysis based on a multibody dynamics analysis and wear volume from a wear model by British Rail Research. The wear volume at a radius of 300 m is dominant compared with other radii. The wear volume was calculated by assigning different coefficients of friction to the tread and flange of the wheel to investigate the effect of lubrication on the wear characteristics. The effect of the improvement by lubrication is calculated by varying the radius of the track, and is assessed on an actual urban railway section.