• Steel and Composite Structures
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• v.37 no.4
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• pp.493-501
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• 2020

The paper describes an optimization method based on the mathematical model of interaction within multibody 'bridge-track-cars" dynamic system. The interaction is connected with considerable dynamic phenomena influenced by high traffic speed (up to 400 km/h) on high-speed railroads. The trend analysis of a structure is necessary to determine the direction and resource of optimizing the system. Thus, scientific methods of decision-making process are necessary. The process requires a great amount of information analysis dealing with behavior and changes of the "bridge-track-cars system" that consists of mechanisms and structures, including transitions. The paper shows the algorithm of multi-criteria optimization that can essentially reduce weight of a bridge superstructure using big data analysis. This reduction is carried out in accordance with the constraints that have to be satisfied in any case. Optimization of real steel-concrete beam is exemplified. It demonstrates possibility of measures that are offered by the algorithm.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.290-299
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• 2002

The Korean railroads' logistics are facing the important turning points by the connection of. South and North Korean railroads, and the commercial opening of the High Speed Rail. These two factors demand several plans for the development of railroads' logistics, in which intermodal transportation with the others modes is wholly studied. In this respect the case of port of Hamburg, Germany, where railroads are completely integrated in the port, will permit the Koreans some useful lessons for the future of railroads' logistics.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.9
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• pp.773-776
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• 2014

KTX (Korea Train eXpress) is the first high-speed train operated in Korea and its highest speed reaches 300 km/h. Korean high-speed trains are mostly operated on the railroads exclusively designed for high-speed trains, but the sections of Seoul~Gwangmyeong, nearby of Daejeon station and Dongdaegu are operated on the existing tracks having the speed less than 150 km/h. With this paper, we'd like to analyze the lateral force that occurs between the wheels and the rail when high-speed trains were operated on the existing track section to suggest an appropriate driving speed for high-speed trains. As the rigid wheel base of the high-speed train is 3m which is about 50% longer than normal vehicles, it works as an advantage for high-speed driving. However, as the lateral force becomes higher than normal vehicles when driving on curves, plans to reduce wear-outs on the wheels are required.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.253-258
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• 2002

The Incheon International Amort Railroad (IIAR) is the railroad that connects Incheon International Airport, Gimpo Airport and Seoul Station. IIAR is now under construction, and it will be finished to Gimpo Amort by 2006, to Seoul Station by 2008. But IIAR is not only so late to start but also has no discussion about effective connecting methods to existing railroads and fine operation plan. Therefore, after IIAR opens, it is possible for IIAR to lose to limousine bus using highway. So, this paper proposes 4 effective connecting methods for IIAR - (1) Shuttle transport, (2) Short-distance connecting transport (Inside IIAR, Seoul Subway Line 9, 'Han-River line') (3) Mid-distance connecting transport (Jung-ang, Tae-baek, Young-dong line) (4) Long-distance connecting transport (Korean Train express (korean high speed railroad)) These methods can increase the connectivity of IIAR with existing railroads and the competition power of IIAR against highway.

• Structural Engineering and Mechanics
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• v.13 no.5
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• pp.505-532
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• 2002

In this study, the analysis of high-speed vehicle-bridge interactions by a simplified 3-dimensional finite element model is performed. Since railroads are constructed mostly as double tracks, there exists eccentricity between the vehicle axle and the neutral axis of cross section of a railway bridge. Therefore, for the more efficient and accurate vehicle-bridge interaction analysis, the analysis model should include the eccentricity of axle loads and the effect of torsional forces acting on the bridge. The investigation into the influences of eccentricity of the vehicle axle loads and vehicle speed on vehicle-bridge interactions are carried out for two cases. In the first case, only one train moves on its track and in the other case, two trains move respectively on their tracks in the opposite direction. From the analysis results of an existing bridge, the efficiency and capability of the simplified 3-dimensional model for practical application can be also verified.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.211-219
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• 2005

The railway industry of each country has variant technical standards and regulations unlike other industries. For this reason, it is necessary to investigate the domestic technical standards and regulations and to prepare the countermeasure of the variance for advancing the korean high-speed railroad system into foreign market. This study was designed to investigate the railway design/manufacturing, examination/inspection and safety of domestic and foreign countries subject to a world market for advancing the korean high-speed railroad system into a foreign market. Because the reliance of a railroad system is a prerequisite for the safety of railroads, it is very important to obtain the reliance data, which is based on the RMS analysis of foreign countries subject to a world market.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.4968-4974
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• 2010

Electrical Railroads provide electric power, which can operate vehicles, via feeder wires. And the supplied current returns to the transformer substation through lines and ground net. In domestic cases, the configuration of ground net affecting such a return current mostly uses an exclusive earth method. However, along with the introduction to Gyeongbu HSL(High Speed Line), the concept of Common Earth was applied to Electrical Railroads. In this paper, based on the return currents analyzed to be measured in the electrified sections for the operation of High Speed Rails in existing lines, we analyze the relations between earth methods and return currents in electrified sections. For analysis, we utilize the measured values of return currents measured in track circuits in Gyeongbu HSL, and predictive values of those compared to the earth methods between Gyeongbu HSL and the existing electrified sections.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7949-7956
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• 2015

This paper introduced the RAR(Reinforced Abutment for Railroads) to reduce settlement of transitional zone and horizontal displacement of abutment by constructing backfill before abutment. We expect that it has more economical and better performance which was validated by numerical analyses. First, transitional zone settlements and horizontal displacements of existing abutment were evaluated for various heights and ground conditions by using finite element analysis program. Then, numerical analyses of it under the same conditions were performed and its results were compared with existing abutment's ones. From the numerical analysis, we found that the responses(settlement and horizontal displacement) of transitional zone of the RAR is about 20% and 34% of one of existing abutment due to the effect of backfill stabilizing. We expected that the RAR having small foundations could be economic way to construct abutment with the control of responses such as, settlement, horizontal displacement, and earth pressure.

• Corrosion Science and Technology
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• v.6 no.6
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• pp.308-310
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• 2007

The owner of underground metallic structures (gas pipeline, oil pipeline, water pipeline, etc) has a burden of responsibility for the corrosion protection in order to prevent big accidents like gas explosion, soil pollution, leakage and so on. So far, Cathodic Protection(CP) technology have been implemented for protection of underground systems. The stray current from DC subway system in Korea has affected the cathodic protection (CP) design of the buried pipelines adjacent to the railroads. In this aspect, KERI has developed a various mitigation method, drainage system through steel bar under the rail, a stray current gathering mesh system, insulation method between yard and main line, distributed ICCP(Impressed Current Cathodic System), High speed response rectifier, restrictive drainage system, Boding ICCP system. We installed the mitigation system at the real field and test of its efficiency in Busan and Seoul, Korea. In this paper, the results of field test, especially, distributed ICCP are described.

• Proceedings of the KSR Conference
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• 2001.05a
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• pp.381-386
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• 2001

In many countries the slab track of railroads is mostly applied on the railroad bridges and tunnels, however it hasn't been constructed in the tunnel in Korea. Presently the Korea high speed railway construction authority is planning to construct slab track in the tunnels to minimize the cost of maintenance and repair. In this study, dynamic characteristics of the railroad roadbed which was constructed using crushed stones obtained from tunnel construction was investigated through the field investigation, real scale model test and numerical analysis. As a conclusion, the roadbeds built with the crushed stones produced at the tunneling site satisfy the requirement of roadbed in terms of displacement and earth pressure for the slab track in tile tunnel.