• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1071-1077
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• 2004

This paper is presenting the performance evaluation on the installed concrete panels. As a result of the evaluation, the resistance to track displacement of temporary support structure was improved and it resulted in the improvement of work stability during installation. And, by the application of new technology and the saving of concrete consumption, both workability and cost were improved and, therefore, the shorter project period and cost saving can be expected. Furthermore, as a result of noise & vibration measurement at site, it has shown good effects of anti-noise and anti-vibration. In conclusion, this process was proved as very effective for track improvement.

• 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.

• Geomechanics and Engineering
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• v.15 no.3
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• pp.911-917
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• 2018

This paper concerns a numerical investigation on the effect of construction sequence on three-arch (3-Arch) tunnel behavior. A three-arch tunnel section adopted in a railway tunnel construction site was considered in this study. A calibrated 3D finite element model was used to conduct a parametric study on a variety of construction scenarios. The results of analyses were examined in terms of tunnel and ground surface settlements, shotcrete lining stresses, loads and stresses developed in center column in relation to the tunnel construction sequence. In particular, the effect of the side tunnel construction sequence on the structural performance of the center structure was fully examined. The results indicated that the load, thus stress, in the center structure can be smaller when excavating two side tunnels from opposite direction than excavating in the same direction. Also revealed was that no face lagging distance between the two side tunnels impose less ground load to the center structure. Fundamental governing mechanism of three-arch tunnel behavior is also discussed based on the results.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.562-567
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• 2001

In this study, performance of reinforced railroad roadbeds with the slag(HMS-25) and soil were investigated through the real scale railroad roadbed tests. Several real scale reinforced railroad roadbeds were constructed in the laboratory with different subgrade conditions and were tested with the estimated actual train loads including the impact loading of train. The affecting factors such as plastic ＆ elastic settlement roadbed layers as well as surface of rails were measured. The settlement at rail surface and roadbed surface of case of soil and slag roadbed comparative with good roadbed site were 2.3, 5.7 times and 1.9, 1.6 times, respectively.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.119-125
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• 2000

In this study, field measurements and analysis of vibration before and after the installation of continuously welded rail were performed. The vibration data obtained at the same locations before and after were analyzed to find out the characteristics of vibration level. The component of train-induced impulsive vibration at the rail joints varies depending upon the distance from the source, however mostly low frequency vibration which propagates long distance causes the problems of vibration. Even though it is expected that there may be certain degree of discrepancy in the amount of reduction in vibration depending upon site ground conditions, it was found that installation of continuously welded rail shows reduction in train-induced vibration.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1113-1120
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• 2007

In this study, as a part of research which is to make 50kg NSI PC sleeper Turnout, the main objective of this study are the development of the PC sleeper and the applications H-type guard, 1/40 cant in the turnout, the same position of the switch, incident angle=0, the same skelton. we completed development and laid 50kg NSI PC sleeper turnout at the Shintanjin station. Now we are inspecting the turnout in site every weeks.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.404-411
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• 2007

Reinforced roadbeds are valued from the point of view of maintenance as well as enhanced mechanical capacity. They support more train load and less transmit to the sub-layers than general roadbeds. Also, the lateral sloping surface of the reinforced roadbed and its low permeability, achieved by the controlled compaction, increase drainage capability and prevent the softening of sub-layers. In the study, a series of cross-hole tests was performed to observe the temporal changes in the stiffness of reinforced roadbeds, if any, due to the cyclic loading of trains and alternating rainy and frozen seasons at Pyeong-taek experimental site. The three types of reinforced roadbed materials are slag, crushed stones, and soils, and the thickness of all the reinforced roadbeds is 0.8m. The stiffness of the slag and soil reinforced roadbeds was not changed or slightly decreased. The stiffness of the crushed stone was somewhat increased and is inferred to being densified close to surface.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1470-1477
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• 2010

In 2004, Korea has become the world's fifth-express train states, Honam high-speed railroad which goes down another line with existing Kyoungbu high-speed railroad is divided 19 construction sectors, its total length is 230.9 km and it will be constructed by 2017. This site is located in Jeollabukdo Jeong-eup district along 9.38 km. There are three representative bridges. ;One is the PSC box girder bridge, another is the Extradosed bridge, and the other is the three continuous spans half-through hybrid arch bridge. This paper shows a planning and design of these bridges.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.527-532
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• 2010

In this study, vertical and horizontal accelerometers were installed at the both side of car body and tachometer was installed on the bogie, for the purpose of stability analysis of Korail Airport Express Train during driving. By applying the developed algorithm, the peak-to-peaks of horizontal and vertical acceleration which were matched with location by tachometer were found and compared with the threshold values. The threshold values per velocities which were presented in the "Metro Train Performance Criteria" were applied here. The validity of the developed algorithm was shown by comparing the site investigation and the measured values at frost heave locations.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1997-2001
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• 2010

Generally, railroad soil around turnout was caused by leakage of lubricant oils during its maintenance. So, TPH concentration in soil was much higher than standard in Soil Envirnment Law. In additiont, railroad site was still difficult to assess due to railcar operation. This research was conducted to investigate the effect on electrolyte concentration during the Electrokinetic-Fenton process for contaminated soil around railroad turnout. As a result, experimental result shows that TPH removal in soil and amount of EOF were changed depending on electrolyte concentration. In future, the removal efficiency can be enhanced to optimize concentration in EK-Fenton Process.