• Proceedings of the KSR Conference
• /
• 2001.10a
• /
• pp.494-499
• /
• 2001

This research carried out the experimental manufacture of the improved fastening device and its performance test as well as the structural improvement of the prototype of a new type of fastening device developed through G7 Project during the first year of the second phase. Firstly, a supplementary design for each part of the prototype was carried out in order to improve its performance and a structural analysis in order to review the stress on the fastening spring. Secondly, another prototype was manufactured and then a performance test was carried out with the criteria used for the same kind of test on the authorized ones, both at home and abroad. Finally, the usability of the device was reviewed by comparing above-mentioned test result with that of those already under commercial use.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.3
• /
• pp.1243-1251
• /
• 2013

The purpose of this study is to investigate the influence of initial clamping force of tension clamp on the performance of an elastic rail fastening system used in sharp curve track. In this study, the initial clamping force and the increasing lateral wheel loads were conducted in the analytical and experimental study, i.e., finite element analysis, laboratory and field test. Using the analytical and experimental results, the performance of the tension clamp was investigated. It was found that the stress of tension clamp depends on the initial clamping force. Therefore the initial clamping force appeared to directly affect the compression stress of the tension clamp. It was found that the compression stress of tension clamp was transferred to the tensile stress by applied the lateral wheel load in service sharp curve track. Further, it was concluded that the initial clamping force was applied on the strengthening force for the tension clamp and then the appropriate initial clamping force was important to ensure a stable performance and long term endurance of tension clamp.

• Elastomers and Composites
• /
• v.53 no.4
• /
• pp.220-225
• /
• 2018

Resilient pads play a major role in reducing the impact of loads on a rail in a rail-fastening system, which is essentially used for a concrete track. Although a compression set test is commonly used to measure the durability of a resilient pad, the static spring constant is often observed to be different from the fatigue test. In this study, a modified compression set test method was proposed to monitor the variations in the compression set and static spring constant of a resilient pad with respect to temperature and time. In addition, the life of the resilient pad was predicted by performing an acceleration test based on the Arrhenius equation.

• 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.818-823
• /
• 2004

In case of the Korea Railroad, when we would decide the track structure, it has been introduced the whole track structure system based on only the foreign application cases and data offered by manufacturers without the process of the objective performance verification. The value of property for track materials, derived from the calculation of track structure, was hard to perform the objective performance evaluation among track structure systems because each manufacturer adopted the different test method and standard. To solve the above-mentioned problem, it should suggest the technical and objective evaluation method about the performance of track materials and meet with the standard of High Speed railroad and international railroad through the establishment and revision of performance standard. In the objective and technical respects, it will be a major role to decide the track structure. In this paper, I would like to summarize the case which was improved the problem of test method and standard exposed from the performance verification of Rail Fastening System among the track structure systems of High speed railroad.

• 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.

• 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
• /
• 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
• /
• 2000.05a
• /
• pp.487-494
• /
• 2000

For the rail fastener clip shoulder being used in Pandrol e-cilp type fastening system, there has been a need to make a structural and electrical improvement due to the fact that PC concrete sleeper showed material loss in the vicinity of exposed portion of the clip shoulder and the fact that track signal was lost when a track insulation block is missing on the track. In the present study, a new lightweight rail fastener clip shoulder with enhanced electrical insulation capability is developed