• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.8
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• pp.481-485
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• 2003

In electric railway system, potential of rail has been risen, for return-current flows through rail. The magnitude of rising voltage is different to railway feed system, ground admittance of rail and the load current. If rising voltage of rail is large, electric shock can be occurred to passengers and maintenance- worker, In this paper, we estimate the rising voltage of rail in high speed railway system and check the safety to human beings.

• Journal of Mechanical Science and Technology
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• v.20 no.10
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• pp.1548-1556
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• 2006

Appropriate contact force is required for the pantograph on the high speed train to collect current from the catenery system without separation. However, at high speed, large aerodynamic lifting force is generated by the contact plate and the body of pantograph, which may cause wear of the contact wire. In this study, to confirm the interface performance of the pantograph on Korea High Speed Train, a method to measure the contact force of the pantograph was proposed and the related measuring system was developed. The forces acting on the pantograph were clarified and a practical procedure to estimate the forces was proposed. A special device was invented and applied to measure the aerodynamic lifting force. Measured contact forces were displayed by the developed system and evaluated based on the criteria.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.534-539
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• 2001

This paper presents the critical speed analysis of geogrid-reinforced rail roadbeds on soft soil. A rail roadbed on soft ground must be designed to avoid intolerable stress in the underlying soil and to give sufficient support for the rail system. At high speeds, the deformation of rail systems will gain dynamic amplification, and reach excessive values as a certain speed, here termed critical speed is approached. The elastic Winkler foundation model was used to predict the critical speed of geogrid-reinforced rail roadbeds on soft soil and the model properties were determined by the in-situ cyclic plate load test. Based on the parametric study of elastic beam on Winkler foundation model, the critical speed increase with the increase of the flexural risidity of subgrade EI and the stiffness coefficient of Winkler foundation k. From the in-situ cyclic load tests and analysis of elastic beam on Winkler foundation model, the critical speed increase with increase in number of reinforced layer and non-dimensional value for depth of first geogrid layers and the thickness of reinforced rail roadbed u/d.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1228-1233
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• 2006

Since 1996, the G7 R&D and High-Speed Rail development project have been accomplished and it will be completed in 2007. During that time, we have achieved the origin design technique based on technique development experience. However, in order to magnify and to promote the growth of the origin design technique for railway industry to be a growth motive industry in future from intensive speed elevation and new technique competition of advanced nations, we need to prepare the next generation high-speed rail technique and to sustain expansion of the technique with getting hold of new technique tendency of the world. Therefore, this paper make research into necessity of the next generation high-speed rail development project, making an analysis of foreign countries cases and forward plan.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.316-321
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• 2003

The railroad is a means of large transportation which has many talents such as a safety and a regularity. That is a results from various confidential performance tests and evaluations of the system. The railroad system consist of various subsystems - vehicle, power supply, signal, communications, track structures, operations, etc. Among them, as an item of safety evaluation there is a measurement of wheel/rail force, so called a measurement of derailment coefficient. This is a very important item because a derailment of a train will bring about a big accident. Especially it is more important in high speed rail of which operation speed is over two times as fast as existing rail. In this paper, it is introduced to preprocess the wheelset for measuring wheel/rail force of high speed rail, such as to treat a measuring wheelset, adhesion of strain gauges and static load test, running test result of main line.

• International Journal of Railway
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• v.7 no.1
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• pp.24-33
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• 2014

The Korean high-speed rail (HSR) began its commercial service in 2004. This service has been created significant changes in the system of intercity passenger travels of Korea. However, the actual ridership was approximately half of the estimated one in the planning stage. In this background, this paper presents the difference between the stated preference (SP) before the HSR service and the revealed preference (RP) after it using the intercity travel mode choice models. Several meaningful differences are found in terms of the factors affecting the travel mode choice, the estimation results of model, the monetary values of time, and elasticities. While the access/egress travel time of high-speed rail is less important than in-vehicle travel time in the SP sample, they have same weight in the RP sample. Also the RP models show that the probability of choosing HSR can be decreased by the increase of the number of vehicles in household contrary to the results from the SP models. The monetary values of travel time are relatively high and the direct and cross elasticities in response to changes in level-of-service of HSR are relatively low in the RP sample. This Korean case is expected to offer referable material for preparing high-speed rail services in other countries by showing the difference between the SP and RP before/after the actual service, identifying the importance of access/egress travel time and lower direct elasticities of HSR demand.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1056-1064
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• 2008

It is estimated that the running of locally-developed next generation High Speed Trains with maximum speed of 400km/h will help to deteriorate track components. It was presented rail defect coding system in UIC 712R includes the definitions of damage types of rail, maintenance procedures, and etc to detect and maintain. It is necessary to make a track maintenance manual determining track maintenance periods using the standardization of damage types of track components such as: sleeper, fastener, elastic pad. In this paper, the damage types of high speed track components are investigated by referring domestic and foreign literatures. And then the damage types of rail given in UIC 712R is reclassified more particularly and classified damage types of track components using internal high speed railway. In conclusion, this paper suggests standardization for damage types of track components on internal high speed railway.

• Magazine of korean Tunnelling and Underground Space Association
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• v.3 no.2
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• pp.32-44
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• 2001

Most of the major aspects of the high speed rail tunnels in Korea, including such items as the tunnel geometry, excavation methods, primary support, final lining, drainage and waterproofing, are similar to the practices followed in other countries. The tunnels in Korea provide the largest net internal area $(107\;m^2)$ as compared to the other counties addressed in this paper. The effective adaptation and modification of international practices and designs, combined with the integration of domestic practices, has resulted in the successful construction of these large tunnels. The experience gained from the completed work to date on the high speed line in Korea, combined with international technology input, will help to ensure future tunnels are constructed in an efficient manner with adequate design measures implemented for the long-term operational life of the tunnels. As has occurred in these other countries, further improvements and modifications to the Korea high-speed railway tunnels will occur as experience is gained and new technology develops.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2115-2124
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• 2011

The rail surface defects which are generated on repeated rolling contact fatigue are getting increased according to high speed, high density, and minimum weight. In addition, Increasing noise and vibration are affected by these also impact load generated as well. Because of this phenomenon, more serious and critical damages were occurred. In fact, in order to control them, the rail grinding were conducted. However, there are not enough researches to make an criteria of generating optimal rail grinding amount in Korea. This study evaluated how depth of hardening on rail surface is formed and suggested optimal rail grinding amount by RCF(rolling contact fatigue) test with generated contact pressure between KTX wheel and UIC60 rail by applying FEM analysis. Therefore, the amount was generated approximately 0.2mm/20MGT to maintain integrity of rail surface by getting rid of depth of hardening on rail according to rail accumulated passing tonnage.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.111-115
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• 2002

The TGV has been developed in a competition with the domestic air transport. But recently, with congestion, do-regulation of air transport and with the increase of number of cities served by the TGV, operators of rail and air transport are looking for a complementarity between the two modes. In this paper, we'll analyse the background and development of high-speed rail-air links in France for a development plan of high speed transportation network in a national level in Korea.