• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.04a
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• pp.485-492
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• 2000

In the rail facilities the rail track consists of rail tie fastening accessories and bed,. The rail track is largely divided into Ballast Bed Track(BBT) and Concrete Bed Track(CBT) according to the type of bed. In this thesis among Concrete Bed Track slab track which is used for the Japanese high speed railway is a target of this study. Dynamic analysis by using finite element method are performed. where moving rain load is periodic function. Then through parametric study some conclusions are obtained as follow. Cement Asphalt Mortar(CAM) affects contrary mechanical behavior to rail and slab greatly. Therefore change of CAM spring coefficient should be handled with care, For slab thickness thin slab is more profitable to reduction of vibration of rail than thick one but mechanical capacity of slab is deteriorated, Improved structural type is proposed then structural analysis is performed for this one. This type is effective to reduction of vibration of railway system.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.493-598
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• 2000

In the rail facilities, the rail track consists of rail, tie, fastening, accessories and bed. The rail track is largely divided into Ballast Bed Track (BBT) and Concrete Bed Track (CBT) according to the type of bed. In this thesis, among Concrete Bed Track, slab track, which is used for the Japanese high speed railway, is a target of this study. Dynamic analysis by using finite element method are performed where moving train load is periodic function. Then through parametric study, some conclusions are obtained as follows. Cement Asphalt Mortar (CAM) affects contrary mechanical behavior to rail and slab greatly. Therefore, change of CAM spring coefficient should be handled with care. For slab thickness, thin slab is more profitable to reduction of vibration of rail than thick one but mechanical capacity of slab is deteriorated. Improved structural type is proposed, then structural analysis is performed for this one. This type is effective to reduction of vibration of railway system.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.3214-3219
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• 2011

HONAM High Speed Railway project is under construction with the target to have 350km/h design speed from Songjeong Gwangju City to Osong. The track for the whole section of the line is scheduled to be a concrete track in order to decrease total life cycle cost (LCC) according to the decrease of track destruction. However, the study on the related parts to increase the train speed up to 400km/h is on going in order to strength the competitiveness of high speed railway. On this study, the stress of track has been analyzed according to the concrete track design method of Eisenmann using equivalent depth theory proposed by Odemark for behavior analysis of concrete track on track bed, which is having embankment deformation characteristics by train load. The behavior analysis of track is performed to analyze the stress of track bed layer and track according to the variation of design load and train speed. And also, the characteristics of concrete track have been figured out by analyzing the parameter according to the thickness of track bed layer.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.6
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• pp.593-599
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• 2012

To analyze the effect of the track structure on the running performance of the railway vehicle, we studied on the vibration and ride characteristics of the high speed train. As results, vibration and ride level of high speed train on the concrete bed track is more reduced than on the ballast bed track. Peak-peak value of carbody vibration on the concrete bed track at 300km/h is half of the peak-peak value of carbody vibration on the ballast bed track. Ride level on the concrete bed track at 300km/h is same level as that on the ballast bed track at 250km/h. Thus, Vibration and ride performance of the high speed train on the concrete bed track is greatly improved compared with that on the ballast bed track.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1029-1037
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• 2008

As for track maintenance, Seoul Metro executes track bed improvement project from obsolete ballast track bed to concrete track bed in order to achieve maintenance free and to extend its LCC(Life Cycle Costing). When it comes to obsolete ballast track bed withdrawal task, now it is done solely relying on man power and ballast inhalation vehicle. In this paper, I suggested ballast cleaning system with lighter equipment to change manpower withdrawal tasks to mechanized ones. It is expected to improve work efficiency and economic benefits by applying track excavator having variable wheels and container etc, which is able to keep on the site.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1542-1549
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• 2009

The function of subgrade in the railway is to support track load on the subgrade as well as train load. Unlike the traditional railway, the uppermost subgrade layer in the Gyeongbu high speed railway was constructed as the reinforced road bed. The reinforced road bed comprises sub-ballast in the upper part and grade ballast in the lower part. The filling material such as soil and rocks in the subgrade can be settled by consolidation of original ground, compression due to self weight, plastic displacement due to train operation, and unequal settlement due to embankment material or improper compaction, therefore many efforts have been given for sufficient compaction and use of proper filling materials in the construction stage. The purpose of this study is to investigate the deformation state of subgrade in the Gyeongbu high speed railway. The investigation on the subgrade settlement was performed by choosing representative sections suspected to be settled based on the previous GPR test results and track maintenance history, measuring the settlement for some time period after installing settlement measuring instruments on and under the reinforced road bed. and analyzing the long-term subgrade settlement data from monitoring system which was installed at the construction stage of the high speed railway.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.370-375
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• 2005

Floating sleepers in a ballasted track increase both track deterioration and track irregularities. Consequently, a considerable maintenance work is required and maintenance cycle is shortened due to the floating sleepers. This paper quantifies the degrees of void between the floating sleepers and a ballast bed. In the future, the influence of floating sleepers on the track will be investigated by an analytical method using a dynamic model.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.580-587
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• 1998

For many decades, the railway was constructed using tracks with jointed rails of relatively short lengths in accordance with rolling and handling technology. The joints cause many drawbacks in the track and lead to significant maintenance cost. So, railroad engineers became interested in eliminating joints to increase service loads and speeds by improving rolling, welding, and fastening technology, Continuous welded rail(CWR) track has many advantages over the conventional jointed-rail track. But in the case of the elimination of rail joints, it may cause the track to be suddenly buckled laterally by thermal and vehicle loads. Thermal loads are caused by an increase in the temperature of railway track. In this paper, CWR track model and CWRB program are developed for linear buckling analysis using finite element method(FEM). The finite element discretization is used with a total of 14 degrees of freedom for each rail element. The stiffness of the fastener, tie, and ballast bed are included by a set of spring elements. The investigation on the buckling modes and temperature of CWR track is presented in the paper.

• Journal of KIBIM
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• v.12 no.3
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• pp.30-38
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• 2022

Railway is compsed in various components, such as subgrade, track bed, sleeper, rail, and overhead line, on a linear space. Therefore, comprehensive work for various design standards and guidelines is required when designing a railway facility. For this reason, much time and effort are required to review the relevant design standards and guidelines. While, automatic legal check system for BIM models has been developed in the architectural engineering, it has not been developed in the railway engineering. This study reviews the korean design standard and the korean code for railway engineering, and suggests some rule items of logical information. Comparing the suggested rule items to the railway BIM library, items of logical information and additional attribute information are obtained. The analysis results of railway design standards and BIM library presented in this study would be utilized for defining rule-set items that is essential for development of the automatic legal check system for railway BIM models.

• Journal of the Korean Society for Railway
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• v.10 no.5
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• pp.487-491
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• 2007

When constructing a high-speed railroad, the reduction of the distance between track centers and the width of track bed will save the construction cost. However the shortening the distance between track centers may cause the stability problems due to higher wind pressure. Therefore the extensive technical review and aerodynamical study should be performed to determine the adequate distance between track centers. In this study, the impact that the increase in wind pressure due to the change of aerodynamic phenomena with the change of the distance between track centers may have on two trains passing by each other was predicted, and the stability of train operation was analyzed in order to review the distance between track centers suitable to Honam HSR trains. And we estimated the aerodynamical effects by the results of the real train experiments.