• Proceedings of the KSR Conference
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• 2004.10a
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• pp.348-356
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• 2004

In this paper, Analysis of parameters effecting on the derailment factor was conducted in oder to deduce technical requisites have to be reflected in design of Track and rolling-stocks because it is important to grasp the risk of derailment quantitatively. And then go far toward becoming practical study with that select two section of sharp curved track of actual train in service, incheon Metro Line 1 and make field research in condition of vehicles and track and analysis As a result of parameter study, the following conclusions were obtained. The radius of curve and Cant is in inverse proportion to the derailment factor, but as train operation velocity, standard deviation of alignment irregularity and the ratio lateral force : wheel load of the inside track increase, the derailment factor rise. In the investigation for the derailment safety of incheon Metro Line 1, the derailment factor was below 0.43 in both section R=200 and R=300, so that it proved safe compare with allowance limits 0.8, but it appeared that risk of the derailment in second transition curve is the highest among the entire curve.

• Proceedings of the KSR Conference
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• 2003.05a
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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.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.12
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• pp.1301-1309
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• 2008

The curved portion fur each section running safety evaluation interpretation according to the track condition for improving the curved portion passage rate of a vehicle by using the multibody analysis model of the Saemaeul train was carried out. As a result, The excess of cant reaches the bad effect to the running safety in case the radius of curvature is small. In case the radius of curvature was large, we could confirm that the deficiency of cant reached the bad effect to the running safety. In the curved portion, the circular curve section most badly showed the running safety. The deficiency of curve length reaches the bad to the running safety. In the curved portion, the circular curve section most badly showed the running safety. Therefore the track condition(cant, transition curve length, etc) can reach the bad effect to the running safety of a vehicle, the exact design is required.

• Journal of the Korean Society for Railway
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• v.7 no.4
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• pp.367-373
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• 2004

The investigation of running stability of the train for curved track is necessary in view of preventing the train from derailment caused by unbalanced forces transferred from the wheel and guaranteeing moderate level of running safety in curve sections. This paper carried out an analysis of running stability of tilting trains in conventional line which the test operation of tilting trains under development are scheduled. For this purpose, the wheel load and lateral pressure to the rail are evaluated. The criteria for the calculated wheel load and derailment coefficient are compared to the design criteria for running stability. It is founded that the running stability of tilting trains for curved track is guaranteed to have sufficient safety and the train speed in curve is governed by the geometric layout of track rather than the criteria for running stability.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.897-904
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• 2008

The major objective of this study is to investigate the effective improvement plan for the curve sections in the conventional lines which the tilting train runs on. 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 and is operating at abroad, was been studying to be suited to natural features. So, in this paper we investigate the improvement method at the sections only where need the extension of the transition curves, and the present status of them for the effective tiling train service using results which were examined on the preceding study which was the development of track system innovation technology for speed-up of them. And we look forward to playing a decisive role as reference material for the decision of the linear fitness in order to operate effectively on the conventional lines for the commercial service of the tilting train, on the basis of checking out the sufficient condition concerned in the track alignment and the velocity which are required in the railway construction rules and the design criteria.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.515-524
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• 2015

The number of occurrence of differential settlement and track irregularity at track transition zone recently comes to increase, which leads to frequent maintenance activities that have an impact on train operation. Such track transition zone damages are attributed to the change of mechanical properties of fill materials due to environmental factors such as rainfall and freeze, and thaw. Consequently, this study attempts to establish the soil water characteristic curve (SWCC) of fill materials, and conduct seepage analysis to assess the distribution of degree of saturation (DOS) for track transition zone in case of rainfall. The SWCC of fill materials was successfully obtained using filter paper test method. The results of seepage analysis revealed that rainfall intensity, the slope of backfill, backfill condition (fill or cut), and SWCC are significantly influential in controlling the distribution of DOS.

• 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.

• Journal of the Korean Society for Railway
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• v.15 no.2
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• pp.172-178
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• 2012

Superimposition of vertical and transition curves is not allowed for all types of tracks in Korean regulation of railway construction. However, this criterion has been established on the basis of difficulty of maintenance of the ballasted track. Comparing with the ballasted track, the concrete slab track has the advantage of maintenance and structural, which allows the superimposition of vertical and transition curves when it satisfies the criteria of running safety and riding comfort. In this study, running safety, ride comforts and track acting forces were analyzed and compared by numerical analysis using VAMPIRE program when the vertical and transition curves are superimposed for the ballasted track as well as the concrete slab track. From the analysis results, it was found that running safety, riding comforts and track acting forces in case of superimposition of vertical and transition curves for the both tracks meet all of the criteria. Therefore, although superimposition of vertical and transition curves for the ballasted track is not allowed because of a lot of maintenance works, it can be applied to the concrete slab track considering the advantage of maintenance and structural safety.

• Journal of the Korean Society for Railway
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• v.12 no.5
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• pp.678-686
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• 2009

A trial run of locally-developed tilting train has been in process on Chungbuk line since the test vehicle was first produced. For the system stabilization, interface verification among the systems including track, structure, catenary and signaling system, not to mention the rolling stock, is very crucial. Therefore, in this study, the dynamic rail force of the tilting (Hanvit 200), high-speed (KTX) and general (Mugunghwa) vehicle caused by driving in transition curve track was measured. And, it compared the tilting response with the other by using the measured rail force data in transition curve track, and then evaluated probability the range of load fluctuation for the variable dynamic vertical and lateral wheel load. As a result, a range of rail force by occurred a change of cant from the high-speed and general vehicle which had fixed bogie structure was distributed throughout small deviation. Otherwise, in case of the tilting train which was consisted of the pendulum bogie structure was distributed wide range about large deviation by changed of cant.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.5
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• pp.572-577
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• 2011

Curve squealing of inter-city railway vehicle is a noise with high acoustic pressure and rather narrow frequency spectra. This noise turns out to be very annoying for the people living in the neighborhood of locations and the passenger in railway vehicle where this phenomenon occurs. Squealing is caused by a self-exited stick-slip oscillation in the wheel-rail contact. Curve squeal noise of railway vehicles that passed by a factor of the speed limit, so to overcome in order to improve running performance is one of the largest technology. In the present paper, characteristic of squeal noise behavior at the Hanvit-200 tilting train test-site. Curve squealing of railway wheels/rail contact occurs in R400~ R800 curves with a frequency range of about 4~11 kHz. If the curve is less than the radius of wheel frail contact due to |left-right| noise level difference (dBA) shows a significant effect of squeal noise were more likely.