• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2010년도 춘계학술대회 논문집
• /
• pp.1991-1996
• /
• 2010

The concrete track system on domestic urban transit has being constructed since 1974. Because a maintenance and repair of concrete track system is convenient, a construction is increased. The concrete track system on domestic urban transit is constructed 71.8% of total track system length and constructed variously, for example STEDEF, LVT, ALT and so on. Recently, railway noise is issued as environment problem. The method for mitigation of urban transit noise is required. In this study to study noise characteristics on concrete tracks we measured noise by concrete track types and analysis the result.

• 한국철도학회논문집
• /
• 제9권6호
• /
• pp.644-651
• /
• 2006

An application of concrete track is being actively processed for the construction of Korean railroad. The concrete track has an advantage to decrease the maintenance ire, but is very difficult system to maintain after earthwork settlement occurred. Therefore, the management and control of embankment and foundation settlement is very important for the successful concrete track construction. We expect that the main part of the settlement of the concrete track is the one of embankment and foundation supporting it. Settlements vulnerable to the concrete track among the causes of lots of settlements are primary consolidation and secondary compression settlement of foundation, creep settlement of embankment, settlement caused by train load, and unequal settlement resulting from the difference of embankment material and construction process. This paper investigated the settlement causes to make badly effects on the concrete track and also evaluated the settlement with field tests and numerical analysis.

• Steel and Composite Structures
• /
• 제24권1호
• /
• pp.113-128
• /
• 2017

This paper highlights a study undertaken on the free vibration of a precast steel-concrete composite slab panel for track support. The steel-concrete composite slab track is an evolvement from the slab track, a form of ballastless track which is becoming increasingly attractive to asset owners as they seek to reduce lifecycle costs and deal with increasing rail traffic speeds. The slender nature of the slab panel due to its reduced depth of construction makes it susceptible to vibration problems. The aim of the study is driven by the need to address the limited research available to date on the dynamic behaviour of steel-concrete composite slab panels for track support. Free vibration analysis of the track slab has been carried out using ABAQUS. Both eigenfrequencies and eigenmodes have been extracted using the Lanczos method. The fundamental natural frequencies of the slab panel have been identified together with corresponding mode shapes. To investigate the sensitivity of the natural frequencies and mode shapes, parametric studies have been established, considering concrete strength and mass and steel's modulus of elasticity. This study is the world first to observe crossover phenomena that result in the inversion of the natural orders without interaction. It also reveals that replacement of the steel with aluminium or carbon fibre sheeting can only marginally reduce the natural frequencies of the slab panel.

• Steel and Composite Structures
• /
• 제25권4호
• /
• pp.427-442
• /
• 2017

This paper presents unprecedented damped oscillation behaviours of a precast steel-concrete composite slab panel for track support. The steel-concrete composite slab track is an innovative slab track, a form of ballastless track which is becoming increasingly attractive to asset owners as they seek to reduce lifecycle costs and deal with increasing rail traffic speeds. The slender nature of the slab panel due to its reduced depth of construction makes it susceptible to vibration problems. The aim of the study is driven by the need to address the limited research available to date on the dynamic behaviour of steel-concrete composite slab panels for track support. Free vibration analysis of the track slab has been carried out using ABAQUS. Both undamped and damped eigenfrequencies and eigenmodes have been extracted using the Lancsoz method. The fundamental natural frequencies of the slab panel have been identified together with corresponding mode shapes. To investigate the sensitivity of the natural frequencies and mode shapes, parametric studies have been established, considering concrete strength and mass and steel's modulus of elasticity. This study is the world first to observe crossover phenomena that result in the inversion of the natural orders without interaction. It also reveals that replacement of the steel with aluminium or carbon fibre sheeting can only marginally reduce the natural frequencies of the slab panel.

• 한국철도학회논문집
• /
• 제19권3호
• /
• pp.341-350
• /
• 2016

철도교량 구간의 콘크리트 궤도는 교량 상부구조의 움직임에 효과적으로 대응할 수 있도록 설계되어야 한다. 이를 위해 일반적으로 전단키로 명명되는 전단키를 교면 보호 콘크리트층(PCL) 위에 일정 간격으로 설치하여 그 위에 궤도 슬래브를 타설함으로써 궤도와 교량 상부구조의 상대 변위에 의해 발생하는 전단력을 전달하도록 설계하고 있다. 이 연구에서는 전단키의 전단 거동을 예측하기 위해 타설 경계면을 고려한 비선형 구조 해석 방법을 제시하였다. 제시된 해석 방법은 콘크리트 면에서의 마찰력과 철근의 다월 거동을 고려함으로써 전단키 타설 경계면(시공이음부)에서의 전단력-전단 미끌림 거동을 예측할 수 있으며, 해석 결과 4개의 시험체에 대한 실험 결과를 잘 예측하는 것으로 나타났다.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 춘계학술대회 논문집
• /
• pp.369-374
• /
• 2007

An active application of concrete track is being expected for the future construction of Korean railroad. For the successful concrete track construction and design in earthwork areas, the residual settlement should be reasonably estimated using the proper method. The concrete track is extremely vulnerable to the damage of residual settlement. However, at the transition areas such as bridge approach, differential settlement will likely occur due to difference of stiffness, poor drainage and poor ground treatment. The maintenance is very difficult for excessive settlement on existing line, it is need to constrain the residual settlement in step of design. In this paper, it is performed the analysis of the residual settlement measured data, test results and reference to understand the residual settlement behavior of concrete track roadbed

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 추계학술대회 논문집
• /
• pp.1121-1125
• /
• 2007

An active application of concrete track is being expected for the future construction of Korean railroad. For the successful concrete track construction and design in earthwork areas, the residual settlement should be reasonably estimated using the proper method. The concrete track is extremely vulnerable to the damage of residual settlement. However, at the transition areas such as bridge approach, differential settlement will likely occur due to difference of stiffness, poor drainage and poor ground treatment. The maintenance is very difficult for excessive settlement on existing line, it is need to constrain the residual settlement in step of design. In this paper, it is performed the determination of the allowable residual settlement through various study to understand the residual settlement behavior of concrete track roadbed.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 춘계학술대회 논문집
• /
• pp.1085-1090
• /
• 2007

In recent railway construction, the concrete slab track is getting highlighted as main stream in track type. However, it is the fact that there are different opinions in selection of the optimized spring coefficient of elastic pad. In this study, the performance of vibration reduction in different stiffness of rail pad for ballasted track was compared, and the changes in characteristics, such as static/dynamic deflection of components, vibration acceleration, insertion loss etc., were analysed by using ISI Program for various types of rail fastening system used in concrete slab track. It was concluded that the fastening system with softer pads has shown the better performance of vibration reduction in concrete slab track and the optimized static stiffness has been calculated to 21.1kN/mm for conventional railways, 17.6kN/mm for high-speed railways and 17.8kN/mm for subways.

• 한국철도학회논문집
• /
• 제17권3호
• /
• pp.193-200
• /
• 2014

본 연구에서는 도시철도 콘크리트궤도 장대레일에 대한 실내피로시험을 수행하였고, 장대레일 잔존수명을 표현한 파괴확률 50% S-N 선도는 적은 실험데이터에 대한 가중치 확률 해석기법을 사용하여 도출하였다. 여기서 피로시험에 사용된 레일들이 누적통과톤수가 서로 다르기 때문에 누적통과톤수를 평균하여 반복횟수를 수정하였다. 또한, 레일표면요철 및 열차속도를 고려한 레일 저부 휨응력은 기존 연구결과 도출된 레일휨응력 예측식을 사용하여 콘크리트궤도 장대레일의 잔존수명을 평가하였다. 레일 피로수명 평가결과, 레일 피로수명이 기준치에 비해 약 2억톤이상 높았다. 또한, 자갈궤도에 비해 콘크리트궤도 레일의 피로수명이 약 3억톤이상 높은 것으로 분석되었다. 따라서 도시철도에서 레일교체기준을 자갈궤도와 콘크리트궤도로 구분할 필요가 있으며, 레일연마를 통한 레일관리가 이루어진다면 기준치가 아닌 목표치로 관리할 수 있을 것으로 판단되었다.

• 한국철도학회논문집
• /
• 제12권3호
• /
• pp.405-411
• /
• 2009

고속철도 신호시스템은 ATC시스템을 이용하여 열차의 제한속도를 송신하고, 일부 도시철도 신호시스템은 이동가능거리를 전송한다. 열차제어정보전송은 직접 궤도를 이용하여 차상에 전송하는 방식, 궤도상에 기기를 설치하여 전송하는 방식, 선로변에 기기를 전송하는 방식이 있다. 직접궤도를 도체로 활용하여 궤도를 회로일부로 구성하고, 궤도에 신호를 전송하여 열차가 궤도에서 열차제어 정보를 획득하는 방법으로, 궤도회로를 사용하며, 고속철도, 지하철에서 사용하고 있다. 궤도회로를 사용하는 방식은 반송신호에 정보를 실어서 보내며, 차상장치는 자기결합에 의해서 정보를 획득한다. 콘크리트 슬래브궤도에는 많은 철근을 사용하기 때문에 자갈도상의 궤도에서는 발생되지 않았던 레일과 철근간의 상호작용이 발생한다. 레일과 철근간의 상호작용이 발생하여 레일의 전기적 특성이 변화된다. 본 논문에서는 경부고속철도 2단계 구간에서 사용되는 콘크리트 슬래브궤도에서 레일과 철근 사이의 모델을 이용하여 콘크리트 슬래브궤도의 모델로부터 레일과 철근 사이의 결합계수를 수리적으로 해석하고, 레일과 철근간의 상호작용이 일어나지 않는 경우, 즉 철근에 의한 레일의 전기적 특성의 변화가 없는 결합계수를 정의하였다.