• 한국철도학회논문집
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• 제15권5호
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• pp.485-497
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• 2012

최근 철도의 소음, 진동에 대한 사회적 관심이 증가하면서, 철도 진동을 효과적으로 줄일 수 있는 플로팅 슬래브 궤도의 적용이 활발히 이루어 지고 있다. 본 연구에서는 플로팅 슬래브 궤도의 동적 거동을 보다 정확히 이해하기 위하여 실모형 실내 실험을 통해 정적 거동과 시스템 고유 진동수 부근의 저주파 대역에서 플로팅 슬래브 궤도의 동적 거동을 분석함으로써 플로팅 슬래브 궤도의 설계의 적정성과 설계에 적용되는 해석모델의 유효성을 입증하고자 하였다. 실험 및 유한요소 해석 결과에 따르면 플로팅 슬래브 궤도는 강체 모드 고유진동수보다 휨모드 고유 진동수에 가까운 대역에서 탁월 주파수가 나타나며 변형 형상도 휨모드가 가장 지배적인 모드가 되므로, 플로팅 슬래브 궤도의 설계 시에는 슬래브의 휨강성과 조인트 및 단부의 경계조건 등을 고려해야 한다. 또한 Kelvin-Voigt 모델을 사용한 2차원 유한요소 해석모델에 의한 해석 결과는 정적 및 동적 처짐, 하중 전달율 등 실험결과와 매우 잘 일치하는 것으로 나타나 플로팅 슬래브 궤도의 설계에 활용하기에 충분한 신뢰성을 가지고 있는 것으로 나타났다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.1065-1070
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• 2004

When the track designer analyze the track structure uses many known & unknown parameters. Unknown parameters, equivalent rail support spring factor, unit rail support spring factor, track damping coefficient, should be assumed. Known parameters are section properties (area, section factor, etc), material properties(modulus of elasticity, mass, etc) and track conditions(wheel load, loading conditions, gauge, etc.). In the assumption of track design parameters, some parameters can be overestimated or under estimated. The purpose of this study is to verify design parameters used in track design, in the way of experimental measurements. Data of displacements, banding stresses, loads, accelerations are measurable at track site. From these data, unknown parameters are derived. Compare these assumed and derived parameters, estimate the entire track stability.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.806-811
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• 2004

Currently, in the design criteria for the high speed railway bridges, the maximum distance between bridge expansion joint is limited to 80m using a continuous welded mil, in order to limit the additional stress in the rail due to the rail-bridge interaction. In the past study on the resonance effect of HSR train, it is known that the reduction of resonance and dynamic responses of bridge deck occurs at the specific expansion length of 28.05m and 46.75m. In this study, the stability of track structure on the HSR bridges with expansion length of 90m has checked by finite element method. And the track behavior including mil stresses and relative displacements are compared to the current state of track structures on the bridge system with 80m long expansion length.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1279-1286
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• 2007

The purpose of a railway track is to provide a smooth surface for safe and economical train transportation. The performance of the track results from a complex interaction of the track and subgrade components in response to train loading and environmental actions. In the past, the role of subgrade as the track foundation were not recognized adequately. There are insufficient information and inadequate methods for subgrade design, assessment and improvement. This situation has survived for a long time largely because a subgrade defect can often be adjusted by adding more ballast under the ties or applying more frequent track maintenance. Therefore, the application of reinforced roadbed technology will be expected to increase in the future. The reinforced roadbed thickness is set depending on subgrade reaction modulus($K_{30}$) in the condition of upper subgrade through PBT in both conventional railroad and KTX railroads. As train velocity (V), train passing tonnage (N), and train axial load (P) are not considered in design, the roadbed thickness could be overestimated (or underestimated). Therefore, in this study has proposed a determination method of reinforced roadbed thickness using design chart made by resilience modulus and properties of earthwork materials.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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• pp.151-156
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• 2003

The purpose of this study is to establish the test procedure of concrete slab track and to estimate the performance of newly developed slab track. The basic direction of conceptual design of KRRI Slab track was determined in the viewpoint of running safety, economic efficiency and maintenance costs. Based on the research results, a detailed conceptual design of KRRI slab track is suggested. For the systematic development of slab track, a comparative study is carried out, comparing merits and demerits of each slab type, and used in the design process of slab track. Slab track tests were performed at lab and the slab track system was improved by the experiment result. Site Test also were performed in test slab track.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.295-302
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• 2007

The objective of this paper is to evaluate the proposed design by the Value Engineering (VE) analysis for the gravel ballast and the concrete ballast track structures. However, reliabilities about the VE analysis results based on Life-Cycle Cost(LCC) has not been fully benefited from VE implementation due to disregard of basic principles and lack of systematic performance measurement systems. In this paper, the VE analysis using the Delphi survey of professional group is proposed to decide reasonable determinants for investment and alternative design in construction project of railway tracks. Moreover, the efficiency of VE analysis is invested by an application of the developed methodology to track structures.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1827-1832
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• 2007

The purpose of a railway track is to provide a smooth surface for safe and economical train transportation. The performance of the track results from a complex interaction of the track and subgrade components in response to train loading and environmental actions. In the past, the role of subgrade as the track foundation were not recognized adequately. There are insufficient information and inadequate methods for subgrade design, assessment and improvement. This situation has survived for a long time largely because a subgrade defect can often be adjusted by adding more ballast under the ties or applying more frequent track maintenance. Therefore, the application of reinforced roadbed technology will be expected to increase in the future. The reinforced roadbed thickness is set depending on subgrade reaction modulus$(K_{30})$ in the condition of upper subgrade through PBT in both conventional railroad and KTX railroads. As train velocity (V), train passing tonnage (N), and train axial load (P) are not considered in design, the roadbed thickness could be overestimated (or underestimated). Therefore, In this study, the computer model, GEOTRACK, was analyzed the influence of reinforced roadbed thickness factors on track modulus and the characteristics of stress pulses in track and subgrade generated by repeated axle loading.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.201-207
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• 2007

At an early design stage of rail track, dynamic analyses using a standard vehicle model of ADAMS/Rail are employed. In the real field, it is very difficult to find an optimal solution on the designing of rail track considering future operating vehicles because the construction of rail track should be done in the advance of vehicle selection and operation. Using a standard vehicle model of ADAMS/Rail, however the better selection among designed rail tracks is possible by comparing the dynamic analysis.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 추계학술대회 논문집
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• pp.463-470
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• 1999

In this paper, a numerical method for evaluating the efficiency of vibration reduction of substructure under slab track is developed for optimal design of floating slab track. The equation of motion for train and track interaction system is derived by applying compatibility condition at the contact points between wheels and rails. The train is modelled by 3-masses system and the track by continuous support beam system. Numerical analyses are carried out to investigate the effect of train speed, stiffness and damping of slab-pad, and track irregularity upon vibration reduction in substructure under the track.

• 한국철도학회논문집
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• 제8권6호
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• pp.500-506
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• 2005

The development of tilting train has been required for speed-up on the conventional electric railroad due to the characteristic of Korean railroad with a lot of curve track. The study and development of a tilting system and a tilting bogie which have a different mechanism with high speed train will play a important role for enhancement of technology for Korean railway. The study for tilting pantograph mechanism to decrease the displacement between a catenary and a center of pantograph happened when the carbody is tilted in order to maintain the ride comfort and stability m a curving track is proceeding with the development of tilting train. In this paper, we introduce the design concept for the tilting mechanism of pantograph and the role and characteristics for several devices adopted in the tilting mechanism of pantograph. Through the kinematic analysis of tilting mechanism, we will obtain and calculate the optimal tilting angular velocity and acceleration in order to keep the contact behavior of a pantograph and a catenary according to tilting of a carbody.