• Proceedings of the KSR Conference
• /
• 2002.05a
• /
• pp.207-212
• /
• 2002

The actual buckling of the railroad track structure is suspected to be a complex interaction between the vertical, lateral and torsional modes. To make the analysis tractable, however, most studies restrict themselves to either the vertical or the horizontal plane. Based on a comprehensive and realistic three-dimensional track model developed in the previous study, three dimensional buckling analysis of CWR track subjected to temperature load was performed. Using the study on buckling temperature and mode, sensitivity of track components such as tie spacing, ballast resistance, stiffness of pad-fastening system and rail size were investigated.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2023.07a
• /
• pp.69-71
• /
• 2023

본 논문은 YOLO 기반 모델의 철도 시스템 내 선로 고정장치 탐지 성능을 비교하고 분석한다. 여기서 철도 시스템은 열차가 주행하기 위한 선로, 침목, 패스너 등의 구성요소를 포함한다. 침목은 지반과 직접적으로 연결되며, 선로를 지반 위에 안정적으로 지지하고 궤간을 정확하게 유지하는 역할을 한다. 또한, 패스너는 선로를 침목에 단단히 고정시키는 역할을 한다. 이러한 선로 고정장치의 부재는 인명 사고로 이어질 수 있어 지속적인 관리와 유지 보수가 필수적이다. 본 논문에서는 철도 시스템의 선로 고정장치 탐지를 위해 YOLO V5 및 V8 딥러닝 모델의 적용 가능성을 실험적으로 접근하며, 두 모델의 탐지 성능을 비교한다. 실험 결과, YOLO V8 및 V5 모델은 모두 뛰어난 성능을 보이는데, 특히 YOLO V8 모델이 더욱 우수한 성능을 보인다. 이로써 YOLO 알고리즘은 선로 고정장치 탐지에 적합하다는 것을 증명한다. 그러나 일부 False Positive Sample이 관측되었음을 확인하고, 이로부터 모델 성능의 개선이 필요하다는 결론을 도출하였다.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2000.04a
• /
• pp.485-492
• /
• 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
• /
• 2000.04a
• /
• pp.493-598
• /
• 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
• /
• 2004.10a
• /
• pp.842-847
• /
• 2004

This study presents the minimum spring stiffness of resilient track pad considering the safety of running train. A nonlinear static 3-D finite element is used for the modeling of railway superstructure, especially for the reflection of nonlinear resistance of rail fastening system. Moreover, ballast is considered as an elastic foundation. As the input load, eccentric wheel and lateral force are used and they are derived from ' Lateral-force/Wheel-load Estimation Equations '. Analysis results are compared with following two values : allowable lateral displacement of rail head (derived from the geometrical derailment evaluation of wheel/rail) and operation standard value (derived from the field test results of track).

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.419-431
• /
• 2007

The track and rail surface geometry is of prime importance on the requirement for track dynamic stiffness, particularly for the speed of 350 km/h, for which both the requirement for fatigue and tensile strength limits require a lower stiffness than 100 kN/mm, which is near the value for ballasted track. However, the track quality has been considered as being the same for 350 km/h as that for 300 km/h, and based on ballasted track, and the track geometry may be kept in better condition with a slab track(probably more similar to the medium quality track geometry of ballasted track). In conclusion, under the condition that the track geometry quality provided by the concrete slab system is fairly good, and that the required maintenance is applied to the rail surface, there would be no safety risk if the fastening system point stiffness reaches 160 kN/mm for 300 km/h operation, and 110 N/mm at 350 km/h.

• Journal of the Korean Society for Railway
• /
• v.16 no.3
• /
• pp.207-216
• /
• 2013

The components of concrete track (rail and rail fastening system) in railway bridge deck ends are damaged and deteriorated by track-bridge interaction forces such as uplift forces and compression forces owing to their structural flexural characteristics (bridge end rotation). This had led to demand for alternatives to improve structural safety and serviceability. In this study, the authors aim to develop a transition track to enhance the long term workability and durability of concrete track components in railway bridge deck ends and thereby improve the performance of concrete track. A time-history analysis and a three-dimensional finite element method analysis were performed to consider the train speed and the effect of multiple train loads and the results were compared with the performance requirements and German standard for transition track. Furthermore, two specimens, a normal concrete track and a transition track, were fabricated to evaluate the effects of application of the developed transition track, and static tests were conducted. From the results, the track-bridge interaction force acting on the track components (rail displacement, rail stress, and clip stress) of the railway bridge deck end were significantly reduced with use of the developed transition track compared with the non-transition track specimen.

• Proceedings of the KSR Conference
• /
• 2005.05a
• /
• pp.550-555
• /
• 2005

In this research, safety requirements for guard rail, buffer stop, car stop scotch block, protection device, fire protection facilities, safety siding, escape facilities and inundation protection facilities are studied to establish a standard. First, various kinds of guard rails and their construction methods are investigated. Researches on the level difference of main track and guard rail, joint, length, and fastening force of guard rail are done. Second, the classification of buffer stop and car stop scotch block and its characteristics are examined, and the impact force, speed limit and capacity of buffer stop are summarized. Details of protection device, fire protection facilities, safety siding, escape facilities and inundation protection facilities are also investigated. From this fundamental research results, basic data on the safety facilities of railroad system are established.

• Proceedings of the KSR Conference
• /
• 2000.11a
• /
• pp.319-327
• /
• 2000

본 연구는 국내 독자기술의 절대적 빈곤속에서 외국기술에만 의지하는 레일체결장치의 국내 현실을 탈피하기 위하여 독자적인 한국형 레일체결장치 개발을 시도하는 것이다. 본 연구에서는 판 스프링은 제외하고 봉 스프링(coil spring)에 대해서만 우선적으로 시제품을 개발하였다. 세계적으로 유명한 체결장치의 장ㆍ단점을 분석하여 장점만을 취하고자 하는 설계 목적을 가지고 새로운 레일체결장치의 개발에 착수하였다. 본 장치의 개념설계를 통하여 유지보수성과 안전성을 동시에 확보할 수 있도록 하였다. 현재 장치의 모형제작을 통하여 조립성 및 가능성을 타진하였으며 전산응력해석을 통하여 체결 스프링 및 숄더의 적정치수를 산정 하였다. 본 연구는 국내에서 본격적인 체결장치개발의 시초가 되기를 희망한다.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.1855-1860
• /
• 2007

The high speed tilting train has superior advantages which are effects on reductions of running time to non-tilting in curves. But in order that the tilting train is operated in conventional track, it is performed evaluation on the running safety. This study carried out an analysis of running stability of tilting train in conventional curved track. The results obtained through this study will be applied to improve the conventional curved track and determine the limit velocity.