• Proceedings of the KSR Conference
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• 2011.10a
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• pp.287-296
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• 2011

Turnout is a mechanical installation enabling railway trains to be guided from one track to another at a railway junction. A movable nose crossing frog is a device used at a railway turnout to eliminate the gap at the common crossing (High manganese, block, assembly crossing)which can cause impact damage, noise and vibration. Our government has a plan speed up of conventional line to 250km/h semi-high speed. We had already developed flexible turnout with fixed crossing(High manganese) and SFC fastening system can cover in the semi-high speed line In this study is about development of the movable nose crossing turnout available Semi-high speed line on concrete track. This paper describes about geometry, attack angle, bending stress at the nose, switching force, safety of continuous welded long rails. This movable nose crossing turnout is expected greatly increases passing speed of turnout in national railway.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.329-336
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• 2011

Urban transit is promoting improvement of the concrete track to solve many problems maintenance in ballasted track. But concrete track has a lot of noise compared to ballated track by multiple reflections. The concrete track is to install sound absorption blocks to reduce noise. And it has a lot of research and effort. This is study analyzed the effect of sound absorption blocks though field measurements, in the range of installed sound absorption blocks. And this was an analysis of the surface shape and sound absorption effects of sound absorption blocks.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1659-1663
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• 2011

Precast concrete slab track is a track structure to be installed by transporting and assembling precast concrete slabs manufactured at the factory. This method can improve concrete quality, provide easy maintenance and reduce construction time, compared with in-situ concrete track. However, the concrete slabs being continuously connected in longitudinal direction, due to the temperature change between summer and winter, the openings at slab joints have occurred. Thus, in this study, to identify the cause of this opening of slab joint, the joint opening caused by temperature drop in the longitudinally continuous precast concrete slab track has been predicted using three-dimensional finite element analysis, and compared with field measurements. Based on the proven model, the slab joint opening, and the stress pattern of concrete slab and steel reinforcement according to concrete slab-base friction properties, concrete-reinforcement bond properties, and prestressing were analyzed.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.955-960
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• 2004

In this study, three dimensional FE analysis of concrete slab track has been performed in order to develop the realistic design of precast concrete slab track. The precast slab track system including the precast concrete slab panel and the grout layer is modeled using the three dimensional solid element with crack softening effect. The input load is computed from the one dimensional beam element model constituting the rail and several discrete springs. To investigate the effect of the longitudinal connection of slab panels, two different systems-continuous and discrete systems - are modeled. The analytical results show that the stresses of both the slab panel and the grout layer are in the range of linear elastic, and, at the interface between two adjacent panels, the primary stresses of the grout layer of the discrete system are higher than those of the continuous system. However, The overall stress levels of the grout layer are very low relative to the strength of th grout.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.104-110
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• 2003

Precast concrete slab track has been already turned out to be more efficient than cast-in place concrete slab track in view of the easiness of construction and the quality control of concrete. Thus, there is a great need to bring in the precast slab track system. In order to develop the realistic precast slab track system that is well conformed to our circumstances, the performance criteria of slab track, and the state-of-the art of precast slab track systems that are used in other countries are briefly discussed here.

• Proceedings of the KSR Conference
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• 2003.10b
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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.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1085-1090
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• 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.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.369-374
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• 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

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1802-1806
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• 2007

The most important factor is the roadbed bearing capacity at concrete track construction. Particularly, in case of rehabilitation, it is essential to secure the uniform roadbed stiffness to prevent the irregular settlement. In this study, reinforced effect of the geotextiles is investigated which is applied to concrete track rehabilitation. The geotextiles is installed two or three layers as the condition of the ground and structure. The reinforced effect of geotextiles is confirmed by the strain gage attached on the geotextiles surface.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1037-1043
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• 2007

The railroad systems with the ballast tracks have been widely used for a long time. But recently, the use of the slab track is being increased gradually with a technical developments. So, this paper deals with the appliance of the slab tracks on the railroad bridges. Firstly, review the design criteria of the railroad bridges related to the slab tracks for the stability and serviceability, based on DIN and EURO code. Then, perform the analysis of the railroad prestressed concrete bridges, and check whether the results of the analysis satisfy the design criteria. Finally, find the construction condition of bridges that all the design criteria are satisfied. As a result, to maintain the stability and serviceability of the bridges, bridges must have some restrictions, including a time of installation of the slab tracks. So, the construction schedule for the erection of the bridges will be carefully considered in case of the concrete railroad bridges with the slab tracks.