• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1132-1140
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• 2007

As it recently appears that Life Cycle Cost Analysis may be considered as new methodology for economic valuation of infrastructure many researches have been made to assess LCC(Life Cycle Cost) of each facility based on a reasonable methods. In general, LCC is composed of construction cost and expected maintenance repair cost. And especially, maintenance repair cost must be estimated to enhance the reliability through systematic and reasonable methods. However in Korea, because high speed railway steel bridges are recently constructed no direct statistical data are available for the account of the maintenance cost and then their maintenance characteristics are not linear yet. Therefore, the approach proposed in the paper utilizes a theoretical determination and degradation of the corrosion and fatigue of the bridges based on Rahgozar et al.(2006)'s model on fatigue notch factor considering into the corrosion to incorporate the corrosion effect into the fatigue strength reduction model. And then, the corresponding probability of failure is calculated in terms of the reliability index using S-N curve to formulate the fatigue limit state. Therefore, this paper proposes the minimum Life Cycle Cost through optimum maintenance plan analysis of high-speed railway steel bridges under construction. Finally, this paper reviews the proposed model in oder to confirm the applicability and feasibility by appling it to high speed railway steel bridges under construction

• Earthquakes and Structures
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• v.24 no.5
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• pp.333-343
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• 2023

Various seismic isolation and reduction devices have been applied to suppress the longitudinal vibration of continuous girder bridges. As representative devices, lead rubber bearing (LRB) and fluid viscous damper (FVD) might suffer from deterioration during the long-term service. This study aims to evaluate the impact of device deterioration on the seismic responses of continuous girder bridges and investigate the seismic behavior of deteriorated LRBs and FVDs. Seismic performance of a simplified bridge model was investigated, and the influence of device deterioration was evaluated by the coefficient of variation method. The contribution of LRB and FVD was assessed by the Sobol global sensitivity analysis method. Finally, the seismic behaviors of deteriorated LRBs and FVDs were discussed. The result shows that (i) the girder-pier relative displacement is the most sensitive to the changes in the deterioration level, (ii) the deterioration of FVD has a greater effect on the structural responses than that of LRB, (iii) FVD plays a major role in energy dissipation with a low degradation level while LRB is more essential in dissipating energy when suffering from high degradation level, (iv) the deteriorated devices are more likely to reach the ultimate state and thus be damaged.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1282-1287
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• 2007

Currently, the Korean railway standards (KRS), managed by Korea National Railroad, have been managed by the Korean Ministry of Construction and Transportation. According to Korean railway safety law, which were established for the guarantee of railway safety, the management of KRS including enactment and revision of technical standards for railway vehicle and components, was committed to Korea Railroad Research Institute (KRRI). In this paper, the detailed master plan for the management of KRS will be introduced for the effective management of KRS, and KRS management direction for the future will be suggested.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.252-257
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• 2005

As the Korea Railroad (KR) was privatized at the beginning of 2005, the Korean Railway Standards (KRS), which was managed previously by KR, have been managed by the Korean Ministry of Construction and Transportation. According to Railway Safety Law and ordinances, which are for the guarantee of safety in railway applications, the management of KRS including enactment and revision of technical standards for railway vehicle and components, was committed to Korea Railroad Research Institute. In this investigation, the detailed management plan and contents are introduced for the effective management of KRS.

• Journal of the Korean Society for Railway
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• v.20 no.5
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• pp.658-667
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• 2017

Rail is the main track component, playing the most important role in safe railways. For the sake of safety, it is strictly required to secure reliability against fatigue and destruction of rail. In this paper, by field measurement on concrete track, it is confirmed that the rail surface roughness and rail bending stress are linearly correlated with each other; the bending stress of rail can be presented as a function of train speed, track support stiffness, and rail surface roughness. The fatigue life of rail can be estimated by deriving the S-N curve through the fatigue test.

• Proceedings of the Korean Geotechical Society Conference
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• 1998.12a
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• pp.1-22
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• 1998

• Railway Journal
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• v.12 no.2
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• pp.13-19
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• 2009

• Journal of the Korean Society for Railway
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• v.18 no.5
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• pp.489-501
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• 2015

This paper analyses the decision process of the Gilhoe Line construction of the Manchurian Railway and consignment process of the North Korea Line to the South Manchuria Railways as part of the 12-year Chosun railway plan. It was found that these two events were connected and could be explained by Japan's consistent continental policy, which had expanded its territory toward China. This paper explicates Japan's railroad policy and the characteristics of the Chosun railway. Moreover, evidence to identify connections among Japan's national railway, the Manchurian railway, and the Chosun railway has been scrutinized. One territory policy between Chosun and Manchuria is also examined. Comparison of new resources on the Gilhoe Line construction of the Manchurian railway and the 12-year plan of the Chosun railway, and their correlations, is expounded. This paper elucidates that the Gilhoe Line construction and the North Korea line consignment operation by the South Manchuria Railways had the intention of obtaining Japanese military and economic supremacy over East Asia.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1542-1549
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• 2009

The function of subgrade in the railway is to support track load on the subgrade as well as train load. Unlike the traditional railway, the uppermost subgrade layer in the Gyeongbu high speed railway was constructed as the reinforced road bed. The reinforced road bed comprises sub-ballast in the upper part and grade ballast in the lower part. The filling material such as soil and rocks in the subgrade can be settled by consolidation of original ground, compression due to self weight, plastic displacement due to train operation, and unequal settlement due to embankment material or improper compaction, therefore many efforts have been given for sufficient compaction and use of proper filling materials in the construction stage. The purpose of this study is to investigate the deformation state of subgrade in the Gyeongbu high speed railway. The investigation on the subgrade settlement was performed by choosing representative sections suspected to be settled based on the previous GPR test results and track maintenance history, measuring the settlement for some time period after installing settlement measuring instruments on and under the reinforced road bed. and analyzing the long-term subgrade settlement data from monitoring system which was installed at the construction stage of the high speed railway.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1069-1074
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• 2021

Recently, mobile communication technology has new eras with supply of 5G commercial communication. 5G mobile communication service is currently supplied with city area, services will be quickly expanded to entire area of country. This mmWave based 5G mobile communication is under spreading for human communication with voice and Internet service. After completion of construction of this human communication, this technology will be expanded to industrial communications. Railway communication system is an example of this industrial communications. In this, performance of traffic transmission for railway communication network based on this 5G railway communication networks will be analyzed with computer simulations. Construction requirements of 5G railway communication networks will be suggested with this analysis results.