• Proceedings of the KSR Conference
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• 2008.06a
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• pp.232-237
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• 2008

Several research institutes including KISTEC and KRRI etc., recently, have studied maintenance activities and performance, in order to determine proper maintenance level and maintenance cost of rail tracks. But it may extremely difficult to make a decision in maintenance matters of concrete track and ballast containing other sub-components. For these reasons, this study investigate variables related to current maintenance, essential maintenance, and preventive maintenance. It is intended to suggest estimation method of proper maintenance cost maximizing rail track performance. It is stated that proposed approach may be very useful to make a decision of proper maintenance level. Typical section of rail track is applied for calculation of life cycle cost according to each maintenance strategy. A proper profile for maintenance is determined minimum life cycle

• Journal of the Korean Society for Railway
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• v.10 no.2 s.39
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• pp.167-178
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• 2007

In general, it is known that the concrete ballast track is possible to reduce a cost of maintenance activities cause of maintenance free by restrictive maintenance in application of track ballast structures. However, if deteriorations and fracture mechanism of a material are considered, proper maintenance activities and repairing are continually required. For the problems, we evaluated an economical efficiency of the gravel ballast and the concrete ballast on a proper level of maintenance activities. As the method based on history path is difficult to obtain sufficient reliabilities cause of an absence of real data for maintenance activities, we chose the delphi survey method by professional group, and we obtained the appropriate index and profiles for maintenance activities. As a result, we founded that effects for cost reduction can be expected by preventive maintenance management, and we proposed economical restrictions and life cycle cost for track ballast structures in a life cycle.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.979-987
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• 2011

The Ballast Track has been widely applied in traditionally due to low initial cost and abundant elastic property. But the disadvantages of Ballast track are; labor-intensive and costly maintenance, weak in high-speed and heavy axial load, in additionally need wide cross section of tunnel and massive substructure in viaduct. Therefore, recent applications tend to more and more towards slab track such as Gyeungbu high speed rail and existing line. The slab track increased the stability, resistance and durability of track, and save maintenance cost compare to the Ballast Track. But the slab track have weakness of track elongation by sub-ballast differential settlement and that threat safety of train operation. Therefor the slab track need to prevent cracks in concrete ballast for insure the durability of slab track. In this paper, review main items and its expected effects of the slab track maintenance standards that control sub-ballast settlement and concrete ballast cracks.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1624-1630
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• 2011

Currently the train operating environment to affect track irregularity is changed rapidly such as speed-up, linear improvement and rolling stack upgrade. The recent track maintenance criteria of track irregularity was quoted from past Japan's, and the needs of revision of criteria are increased because of the rapid change in train operating environment. In case of enhance the track irregularity criteria, it secure driving safety and riding comfort but maintenance cost are increase. And also decrease ballast durability by frequent corrective work. In case of mitigate the criteria, it decrease driving safety and riding comfort, but save the maintenance cost. The study for enacting rational criteria did not carry out so far. In this study, survey the domestic and international track irregularity and case study for track irregularity inspection results and maintenance history for guideline of enacting irregularity criteria study.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.261-267
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• 2010

Present maintenance of a high speed railway is after the fack maintenance that executes a task when measured value goes over threshold value except some planned maintenance. It is difficult from efficient management of maintenance human resource and equipment commitment because it is difficult to predict quantity of maintenance targets. Corrective maintenance is pushed back on the repair priority of other target to need repair and it is exceeded repair cost potentially. For safety and dependable track management because track deterioration prediction is linked directly with track's life and safety of train service, it is very important that track management be based on preventive maintenance. In this study, we propose statistics model of track quality to use track inspection data and forecast model for track deterioration prediction.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.733-739
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• 2011

B2S(Ballasted track To Slab track) that is track system has been first developed in 2004 with foundation of rich experience and know-how of subway track upkeep and mending of facilities in 36 years to improve an existence pebble track at a concrete track. 'B2S' is admitted technology through patent registration in the domestic and Europe and it's made by a factory and put together at field, so it's able to construct precisely and to reduce a construction period. In addition, safety, the ecological balance and durability are excellent, and walking, cleaning, etc. has the advantage of easy maintenance. 'B2S' is currently laying 27.7km at Seoulmetro as of end of 2010 standard, but it'll be expected to be applied to a domestic Metro more from now on. It is possible to classify the total cost resolution structure of B2S system by R&D cost, test production and experiment cost, the initial facility cost, maintenance cost, disposal cost. In this research, it seems useful for selection evaluation which considered the life cycle cost or economics of the concrete track structure by analyzing an initial cost of facilities.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.2
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• pp.110-121
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• 2016

In the decision-making, such as selection of structure, construction method, or time and scheme of maintenance, the evaluation of life-cycle cost(LCC) is of great importance. The maintenance cost occupy a large portion of the LCC of the railway track as well as the initial construction cost. Futhermore, the proportion of the maintenance cost is much higher in the ballasted track. Thus, the importance of the LCC evaluation is higher than in any other engineering structures. In this study, a LCC model that can consider various design parameters such as the type of track structure, annual traffic volume, axle load, train speed, and proportion of curve sections and engineering structures has been developed. Fundamental data for calculating costs also have been presented. Based on the model and data proposed, the trends in the variation of LCC according to the design parameters were examined and the most important design parameters in the LCC analysis of railway track were investigated. The results show that the proportion of renewal and operational costs is much higher in the ballasted track than in the concrete track, and the annual traffic volume and ballast taming period are most significant factors on the LCC of the ballasted track. On the contrary, it is revealed that the proportion of the initial construction costs in the concrete track is much higher, and the LCC of the concrete track is less sensitive to the traffic volume, train speed, and axle load.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1299-1305
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• 2006

In this paper, the objective is an evaluation of economics using Life Cycle Cost(LCC) analysis for the ballasted track and the concrete track. However, since the absence of reliable data on maintenance activities, the degree of a reliability about the results of the LCC analysis is insufficient yet. In order to remedy the problems, we surveyed a professional research group for an approximate estimation which can be represented a degree of maintenance through a application of examples. Hereby we found that it is possible to expect the retrenchment of cost using preventive maintenance management. Moreover we proposed appropriate and economical restrictions between track structures.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.167-172
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• 2011

Generally, the analysis of railroad wear data is most effective method for the efficient railway maintenance. The wear of railway track affects loss of rough ride, noise or vibration of train and traveling safety. Moreover as the track is worn away, this promotes destruction of structural mechanism of rail track which can bring about increasing of rail track maintenance cost drastically. For this reason, it is very important and interested research subject to design railway track structure and to analyse train movement mechanism based on systematic analysis of the reasons causing rail wear possible in real field. In this research, for the efficient maintenance, Life Cycle Performance of rail track and maintenance characteristics are computed considering some track components such as track type, contracting type, sleeper type and roadbed type. Time - Wear probabilistic distribution relationship as well as multiple regression analysis based on time, curvature and wear data are computed to predict the service life remainder of railway track and to be adapted to safety assessment.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.486-493
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• 2007

In the field of maintenance of domestic high-speed railroad which has cost a great deal more than any other fields since it was opened; 1) We found out the conditions of current domestic railroad by understanding the status of track maintenance and analyzing operative processes of track maintenance. 2) The main factors in track maintenance of high-speed railroad, that is, the elements for success to help decision-support in track maintenance were derived from a research on literature about the condition of railroad R&D in these days and about the prediction of the irregular progresses of track. 3) We derived the order of priority and weights from AHP analysis which was based on the survey regarding elements for success.