• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1864-1874
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• 2007

Korean trains pass many mountain areas, so the volume of structures like bridge and tunnel has large part of railway lines. Train speed-up naturally needs a straight line in railway, then structures are increasing, and the length of structure has more than 70% in Kyongbu high-speed railway. The stiffness of bridge and tunnel is higher than the soil in the roadbed in spite of dynamic difference in vibration and displacement. Differences in stiffness have more dynamic effects and increase the deformation and destruction in the track and roadbed. This influences passenger's comfort and the safety of operation, and it needs more track maintenance. This study selected tunnel with ballast track, tunnel with concrete track, and structure's approaches with short maintenance cycle in the roadbed and had track acceleration tests and track liner inspections using track master in the field. This study will measure periodically to structure's approaches which have very fast track irregularity and analyze dynamic differences and track irregularity near structure's approaches, so realize the cause of track irregularity of structure's approaches and use basic data for reasonably strengthening method of structure's approaches.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.437-446
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• 2006

The major objective of this study is to investigate the effects and application of improvement for railway steel plate girder bridge by resilient panel track system. It analyzed the mechanical behaviors of steel plate girder bridge with applying resilient panel track system on the finite element analysis and laboratory test for static & dynamic characteristics. As a result, the improvement of steel plate girder bridge with resilient panel track systems are obviously effective for the static & dynamic response which is non-ballast steel plate girder bridge. The analytical and experimental study are carried out to investigate resilient panel track system decrease vertical acceleration and deflection on steel plate girder bridge for serviceability. And the resilient panel track system reduced dynamic maximum displacements(about 59%) and stresses(about 82%), the increase of dynamic safety is predicted by adopting resilient panel track system. From the dynamic test results of steel plate girder bridge, it is investigated that vertical acceleration and deflection is very low with applying resilient panel track system. The servicing steel plate girder bridge with resilient panel track system has need of the reasonable improvement measures which could be reducing the effect of static and dynamic behavior that degradation phenomenon of structure by an unusual response characteristic and a drop durability.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 춘계학술대회 논문집
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• pp.234-241
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• 2002

In this study, a numerical method which assesses running stability of freight car loading 300m CWR and structural safety of conventional railway track when passing over curves and steel girder bridges is presented. Optimal speed of the freight car is suggest on the basis of numerical reviews for stability of derailment of the freight car and structural safety of track at weak points of the conventional line.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1002-1008
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• 2011

Turnout is a mechanical installation enabling railway trains to be guided from one track to another at a railway junction. there are classified variously according to rail type, sleeper type, fastening system, track type. Construction of concrete track are on the increase recently to secure the safety of track structure as well as to reduce the maintenance cost. SFC fastening system used the plain track a lot and for those reasons, The fast clip turnout demand growing to improving efficiency of the maintenance cost by unification of fastening clip on whole line. in this study is about development of the fastening system for new turnout using fast clip. this fastening system assembled elasticity pad underneath a base plate. its can change stiffness how to adjust contact surface area of elasticity pad Developed fastening system have passed test according to rule of KRS-TR0014-09R (rail fastening system) and Performance Certification by KR.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1848-1859
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• 2011

A subsidiary-main track for passenger station is a low-speed track section distinct from a through route such as a main track. It is parallel to a through track and connected to it at both ends by switches. Sidetracks allow for fast, high priority trains to pass slower or lower priority trains going the same direction. They are important for efficiency to order and organize the flow of rail traffic. In this paper we first describe the minimum headway between trains using the concept of occupation time in a block section, which depends on block systems, signalling system and safety technology. And then a stepwise approach is presented to select station, which is suitable to install sidetrack for a given train-traffic pattern. This approach is tested with sample example data, which are surveyed from track geometry based on the to-be-constructed line.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2838-2843
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• 2011

Recently, the floating slab track that can effectively mitigate the vibration and structure-borne noise is being discussed to be adopted. The floating slab track which is a track system isolated from the sub-structure by vibration isolators. Unsimilarly to conventional track and the slab deflection is large. Therefore, the running safety and ride comfort should be investigated. Especially at slab joint since the load cannot be transferred, the possibility that the dynamic behavior of track and train became unstable is high. Thus, in general dowel bar are often installed at slab joints. To determine the appropriate dowel ratio the load transfer characteristics should be investigated. In this study, dowel bar joint is modeled by equivalent shear spring and this model is verified by comparison with experimental results. Using the proven model, the load transfer efficiency and deflection at slab joint according to dowel ratio, and stiffness and spacing of vibration isolator were examined.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2057-2063
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• 2011

Recently, concrete slab track is mostly used to satisfy requirements for safety of high-speed train operation and economical efficiency of maintenance. Due to structural characteristics of ballast track structures, roadbeds under the ballast experience a state of high stress. In case of slab track structures, however, its roadbeds place on a condition of low stress less than roadbeds of ballast track structures as increasing of the loading area. In this study, vertical earth pressure under slab track structures was investigated through real-scale loading tests and theoretical analysis to compare with each other.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.379-386
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• 2007

Recently the concrete slab tracks are being constructed on roadbed in the Kyong-bu 2nd stage high speed railways. In responding to this trend, new design standards and track materials maintenance systems, based on the slab track material safety and usage perspective, are needed. This research provides the design standards and the maintenance system. The proposed standards and the maintenance system are based on the track theory and the track-train interaction program developed, where the roadbed displacement and train speed are utilized as mediating variables. In the analysis, the dynamic response of track-train interaction apply to various speeds and displacements. the roadbed displacement is shown in a sine curve, the scope of the displacement occurrence, presented in its wavelenths, include 6meters, 10meters, 15meters, 20meters, 30meters. the train speeds involved are 50,100, 150,200,250,300,350,400 kilometers per hour.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.539-545
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• 2009

KTX trains which began passenger service between Seoul and Busan in April 2004 have gained very high evaluation for their safe operation. Track is one of the most important means to keep KTX safety, it has not been a fail of safe structure. The track failure during operation may lead to a severe accident. So, it is to be verified the confidence of track maintenance management on the high speed line. This paper would like to find a track deformation trend through a comparative analysis on actual measurement data at these times. It discusses the effect of cyclic dynamic load at welding part. KTX dynamic impact load was measured in accordance with a rail surface irregularity and analyzed some track irregularities according to the condition of rail profile at welding part in the Gyeongbu high speed line.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.1320-1325
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• 2006

Railway track supports and guides train and it directly affects ride quality and safety. To maintain track quality, regular maintenance activity is essential but it degrades track usage since maintenance activity occupies the track during the work. To achieve maximum track efficiency, track inspection should be performed at commercial running speed. In this paper, we designed and developed high speed rail profile measurement system using laser light sectioning method with line laser generator, digital camera and DSP based image processing system. The measurement system can supports rail profile measurement at the speed of 300 Km/h that can be applied to KTX.