• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.347-354
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• 2001

Extradosed PSC Box bridges, newly emerging type of structures in construction market, have a characteristic in that external tendons are used for strengthening PSC Box girder like stay cables in cable stayed bridges. In this study, a series of constructions stage analysis procedure, including initial shape analysis, backward analysis and forward analysis, have been performed in order to investigate long-term behavior of extradosed PSC box bridges, using PCCAP-a computer program for time-dependent stage analysis of PSC cable stayed bridges. CEB-FIP 1978 model was used for the consideration of time-dependent effect of concrete material. Showing the validity of the analysis results with RM SPACE FRAME, it has been confirmd that time-dependent effects become less consequential as the stiffness of girder becomes larger.

• Journal of the Korean Society for Railway
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• v.9 no.2 s.33
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• pp.137-144
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• 2006

The Extradosed PSC bridge is one of the best alternates which not only covers the longer span than PSC box girder and also performs the role of landmark facility with much cheaper cost than cable stayed bridge. Since the cable-stayed long span bridge is more flexible than general medium span bridges and railway bridges can be experienced resonance phenomenon by repeated equidistant axle loading of the train, it is inevitable to consider the dynamic behavior on impact, deflection and so on. In the present study, the dynamic behavior of an Extradosed PSC railway bridge subjected to moving train forces is analyzed. As well as trains which operate in conventional railway tines, KTX train is also considered. For the estimation of dynamic performances of the Extradosed PSC bridge, vertical deflection, accelerations of the slab, end rotation of the girder and impact on pylons and cables are discussed.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.618-625
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• 2003

The recent development of PSC girder bridges are mostly dedicated for optimization of self-weight, simplification of girder section for easy construction and minimization of maintenance efforts. Moreover some of those bridges are required as a landmark facility which raises the image of locality and harmony with surroundings. An extradosed bridge is one of the best alternates which not only covers the longer span than PSC box girder and also performs the role of landmark facility with much cheaper cost than cable stayed bridge. Hyundai is carrying out the construction of unique style extradosed bridge which have central suspension system and uniform girder depth named Keong-An grand bridge on the Sungnam-Janghowon Express highway. In this paper, major process of design and construction features of Keong-An bridge is presented.

• Journal of the Korean Society of Safety
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• v.31 no.1
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• pp.74-80
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• 2016

In this paper, structural characteristics for an extradosed prestressed concrete box girder bridge are investigated in terms of selective parameters. These parameters are mainly associated with the structural details of the extradosed bridge and derived from currently available literatures regarding previous design drawings. The analyses have been carried out using general-purpose structural analysis program, RM-Space Frame. The parameters evaluated for the present study represent the most salient features of the extradosed bridge and are as follows; 1) span length ratio(side-span length to center-span length), 2) boundary condition of girder, 3) height of pylon, 4) anchorage location of external cables and 5) girder stiffness. The analytical predictions indicate that span length ratio and pylon height are reasonably adequate in the range of 0.55 to 0.60 and $L_m/8$ to $L_m/12$ respectively for the bridge under consideration. Also, demonstrated is the boundary condition of girder, in which rigid-connection details give more efficiency than the continuous details. In addition, considering structural characteristics of the extradosed bridge, it is desirable that the girder stiffness should be determined by the stress range of external cables rather than bending moment of girder.

• 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.1691-1696
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• 2010

Jeong-Ji overbridge is designed to be 9.3km long, the longest for a high speed railway bridge ever constructed in Korea. This bridge is constituted of three types of structure. Standard type bridge is 35m PSC Box bridge which will be constructed by Precast Span Method. To cross the Cheonan Nonsan Expressway, 80m three-span steel arch bridge is designed to avoid rail expansion joint. Finally, Extradosed bridge is planned for high speed railway bridge for the first time in Korea based on originative and advanced design techniques. It is expected that this will contribute to the development of national technology for long-span high speed railway bridges.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.206-213
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• 2008

Mo-Am arch bridge is only the long-span bridge (with 125m span) in the Kyong-Bu high-speed line in service, while other bridges are PSC box girder bridges and steel composite bridges with span lengths of $25\sim50m$. However, in foreign high-speed lines, special cable-supported bridges like cable-stayed bridges and extradosed bridges are being adopted in earnest with technical specifications. The cable supported bridge is recognized as one of the indices of technology in civil engineering field, and thus it is being adpoted with a sense of rivalry in countries with advanced technology in railway engineering. In this paper, to apply the top-level cable-supported bridge technology to the domestic high-speed line up to 400km/h by establishing the technical specifications on cable-supported bridges including span length, the requirements for securing the dynamic stability and running safety of high speed train are analyzed through case studies for domestic and foreign cases.