• 한국철도학회논문집
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• 제9권6호
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• pp.689-694
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• 2006

Most of design parameters of Railway Structures are determined by the serviceability requirements, rather than the structural safety requirements. The serviceability requirements come from Ensuring of running safety and ride comfort of train, reduction of track maintenance working Track-Bridge interaction should be considered in the design of railway structures. In this study, a numerical method which precisely evaluate an axial force of rail and a rail expansion and contraction when turnout exist in succession on a CWR of bridge is developed.

• Steel and Composite Structures
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• 제44권4호
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• pp.473-488
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• 2022

A high-speed railway (HSR) bridge may undergo long-term deformation due to the degradation of material stiffness, or foundation settlement during its service cycle. In this study, an analytical model is set up to evaluate the influence of this long-term vertical bridge deformation on the track geometry. By analyzing the structural characteristics of the HSR track-bridge system, the energy variational principle is applied to build the energy functionals for major components of the track-bridge system. By further taking into account the interlayer's force balancing requirements, the mapping relationship between the deformation of the track and the one of the bridge is established. In order to consider the different behaviors of the interlayers in compression and tension, an iterative method is introduced to update the mapping relationship. As for the validation of the proposed mapping model, a finite element model is created to compare the numerical results with the analytical results, which show a good agreement. Thereafter, the effects of the interlayer's different properties of tension and compression on the mapping deformations are further evaluated and discussed.

• 한국철도학회논문집
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• 제7권3호
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• pp.283-289
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• 2004

According to continuos welded rails on a bridge, temperature changes bring about the expansion of the bridge deck adding axil forces on the track. Moreover, the ballast on the bridge deck expansion joint is moved due to the bridge deck. If bridge decks are longer, the influence is greater, loosening ballast, causing track irregularities, and deteriorating passengers' comfort. Considering structure of bridge itself and tolerance of track irregularities caused by the loosened ballast on bridges, the maximum length of a deck should be less than 80m, which is the same as the standard of the French railway. In this study, an interaction between the expansion related to the bridge length and irregularity in longitudinal level referring to measurements and maintenance works performed in the high-speed railways was analyzed. This research shows that installation of sliding plate or vertical ballast stopper is not a good option since it is difficult to install. On the other hand, installation of movable fastener or gluing is easy but its influence is insignificant. To conclude, switch tie tamping or manual tamping is more effective than others.

• Smart Structures and Systems
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• 제31권5호
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• pp.501-516
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• 2023

Dynamic irregularity and acceleration of bridges subjected to high-speed trains provide crucial information for comprehensive evaluation of the health state of under-track structures. This paper proposes a novel approach for real-time estimation of vertical track dynamic irregularity and bridge acceleration using deep generative adversarial network (GAN) and vibration data from in-service train. The vehicle-body and bogie acceleration responses are correlated with the two target variables by modeling train-bridge interaction (TBI) through least squares generative adversarial network (LSGAN). To realize supervised learning required in the present task, the conventional LSGAN is modified by implementing new loss function and linear activation function. The proposed approach can offer pointwise and accurate estimates of track dynamic irregularity and bridge acceleration, allowing frequent inspection of high-speed railway (HSR) bridges in an economical way. Thanks to its applicability in scenarios of high noise level and critical resonance condition, the proposed approach has a promising prospect in engineering applications.

• 한국철도학회논문집
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• 제12권4호
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• pp.574-581
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• 2009

장대레일이 교량구간에 설치되면, 궤도와 교량의 상호작용에 의하여 부가축력과 변위가 발생하게 되므로 설계단계에서 장대레일의 부가축력 및 변위 검토가 필요하다. 본 논문에서는 장대레일 상호작용에 영향을 미치는 주요 인자들을 변수로 종방향 상호작용해석을 수행하였으며, 교량설계단계에서 장대레일 부가축력 및 변위 검토를 간단히 수행할 수 있도록 설계차트로 정리하였다. 본 논문에 제시된 설계차트는 일반철도 교량에 대한 결과로써, 강교량 및 콘크리트 교량, 지갈궤도 및 콘크리트궤도, 단순교(FM방식) 및 연속교(MFM방식)에 대하여 하부강성 및 상부강성별 설계차트로 구분하여 제시되었다.

• 한국철도학회논문집
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• 제12권4호
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• pp.565-573
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• 2009

장대레일이 교량구간에 설치되면, 궤도와 교량의 상호작용에 의하여 부가축력과 변위가 발생하게 되므로 설계단계에서 장대레일의 부가축력 및 변위 검토가 필요하다. 본 논문에서는 장대레일 상호작용에 영향을 미치는 주요 인자들을 변수로 종방향 상호작용해석을 수행하였으며, 교량설계단계에서 장대레일 부가축력 및 변위 검토를 간단히 수행할 수 있도록 설계차트로 정리하였다. 본 논문에 제시된 설계차트는 고속철도 교량에 대한 결과로써, 강교량 및 콘크리트 교량, 자갈궤도 및 콘크리트궤도, 단순교(FM방식) 및 연속교(MFM방식)에 대하여 하부강성 및 상부강성별 설계차트로 구분하여 제시되었다.

• 전산구조공학
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• 제32권1호
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• pp.15-24
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• 2019

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 춘계학술대회 논문집
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• pp.256-263
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• 2002

This paper deal with optimal design of reinforced track as a track reinforcing method for transition area of track support stiffness in transition area between bridge and earthwork. When vehicle passes through transition area, dynamic properties between vehicle and track are studied by the analysis of vehicle-train interaction for the each case when reinforced tracks are used or not. furthermore, optimum decision of type and length of track are made based on the performance adapting variable parameters : support stiffness of track for bridge and earthwork, heading direction of vehicle and type and length of track.

• 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.

• 한국철도학회논문집
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• 제17권4호
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• pp.245-250
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• 2014

본 연구에서는 콘크리트 궤도 교량의 사용성 설계를 위한 연구로서 궤도 및 교량 설계변수들이 콘크리트 궤도의 레일지지점에서의 작용력에 미치는 영향을 나타내었다. 궤도 구조에 작용하는 작용력을 구하기 위해서 각 레일 지지점의 간격이 다른 부등간격 이산지지보 모델을 유도하였다. 해석 변수는 교량의 교대 또는 교각 위치 부근의 신축이음부의 레일 지지점의 간격, 교량 거더의 받침에서부터 교량 거더 단부측의 마지막 레일지 지점까지의 거리, 그리고 추가 배치한 레일지지점의 수이다. 궤도 구조의 변위를 일으키는 요인으로는 축하중, 거더의 단위 수직단차와 단부회전각이다. 해석결과로부터 레일지지점에서의 최대압축력과 최대부상력을 구하였으며 레일지지점의 간격이 작용력에 미치는 영향을 나타내었다.