• Journal of the Korea Concrete Institute
• /
• v.11 no.5
• /
• pp.21-31
• /
• 1999

The companion paper presents an analytical model to predict behaviors of PSC-Beam bridges according to continuity of spans. This paper aims at providing several examples of its application to PSC-Beam bridge. In this regard, many uncertainties affecting to the continuity of spans (such as the ultimate shrinkage strain of slab and girders, the prestressing creep of girders, and the time adopting prestressing force) are analysis in detail. Moreover, to increase the serviceability and to remove th inherent structural defects including the cracking at interior supports, a necessity for the parametric studies of PSC-Beam bridges reflecting the construction sequence is emphasized.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.05a
• /
• pp.100-103
• /
• 2004

Bridges are deteriorating over service life due to over weight vehicles, environmental conditions and so on. In addition to that, those could be classified into low level bridges which are not fit for highway because of upgrade of the design load. Consequently, such reasons impel the bridges to be repaired or strengthened. Among the rehabilitating methods, FRP sheets and externally prestressing methods are preferred recently. This paper presents experimental results about the behavior of PSC beams strengthened by external tendons and CFRP sheets.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.05a
• /
• pp.552-555
• /
• 2004

For the estimation of the load effects of the slab-an-girder type structures, the applicability of FEM analysis for RC T-type girder bridges using orthotropic plate elements has been studied in the present study. The present study indicates that the analysis by orthotropic plate elements for RC T-type girder bridges gives reasonable results for sectional force, including moments and shear. The results from the present method gives the values in between full composite and non-composite cases, which are reasonable when compared with actual test results.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2003.11a
• /
• pp.591-594
• /
• 2003

It is reported that the amount of reinforcements for domestic PSC box girder bridges is used two times more that those for foreign PSC box girder bridges, which is considered to be irrational and uneconomical. Therefore, we have come to the conclusion through this study that the advanced design direction can reduce the amount of reinforcements under the condition that the static load test and the nonlinear analysis for the specimen of the PSC box girder bridge with reduced reinforcements which is designed by advanced design direction was carried out in order to verify the validity of the advanced design direction.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2003.11a
• /
• pp.363-366
• /
• 2003

This study is to develop a strengthening method for RC slab bridges and rigid-frame bridges with external prestressing. In this study, we design the slab specimen that have a strengthening of the DB-13 and set up the longitudinal tendons placed on both side of slab strengthens the whole bridge, and lateral tendons placed under the slab strengthens the middle of slab, and conveys the load at middle slab to both sides. Structural analysis for the tensile force for strengthening were analysed and we know that displacement and strain was improved from this test. This method has no upward roof work, so it is very convenient for installing. And no spaces under the slab are need, so it is good for shallow slabs which has less space inder the slab.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2010.05a
• /
• pp.61-62
• /
• 2010

This paper provides an analysis using statistical method on the basis of database (DB) of bridge inspection reports performed by KISTEC from 1995 to 2007. Measured impact factors of total 36 railway bridges were classified by the span length, type of bridges and natural frequency. The fundamental frequency and the impact factors of inspected bridge are compared with formulas specified in both domestic and foreign railway bridge design codes.

• Proceedings of the KSR Conference
• /
• 2001.10a
• /
• pp.293-298
• /
• 2001

2span continuous Prestressed concrete girder railway bridges, span length 21m, 25m, 30m, 35m, that down-up method is applied and that designed to satisfy service load in accordance with design criteria of railway bridge can be dropped in their hight compared with existing simply supported prestressed concrete girder railway bridges. Continuous bridges result in guaranteeing safety against bending behavior by loading the practical railway moving load with each velocity. But the natural frequency of span length 21m is estimated not to satisfy recommended limitation of UIC 776-1R..

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.1875-1881
• /
• 2007

Deformations of bridge deck ends on abutments or on transition between bridge decks can cause extreme deformations on track. Especially, since slab track is fixed onto the bridge deck slab on concrete slab track-installed bridges, deformations of bridge deck ends directly affect the track behavior, and thus these interactions can bring about the premature failure of rail fastenings or other deteriorations to lower the serviceability. In this study, a foreign standard to evaluate forces on track components caused by the track-bridge interactions and the serviceability of bridge deck ends is investigated, and for the real bridges, the serviceability of bridge deck ends according to several parameters of bridge and track is analyzed. It is found that arrangements and spring coefficients of bridge bearings, as well as distance between bridge bearing and last rail support, support spacings, rail support spring coefficient, are very important parameters.

• Journal of the Korea Concrete Institute
• /
• v.12 no.6
• /
• pp.43-50
• /
• 2000

In this paper, a new splicing method was applied to design the girder section of bridges with the span length of 25m, 30m, 35m, 40m and 45m. A U-type precast prestressed section was also determined for each bridge. Additionally, the sectional area, beam depth and Guyon's efficiency factor of the spliced U-type sections in each span were analyzed in comparison with the present I-type PSC bridges. As a result, in spite of an increase of 31%∼50% in the sectional areas compared with the I-type precast girders, the spliced U-type the beam depth of the spliced U-type girder was designed as 2,050 mm compared with the I-type precast girder of 2,600mm in a 40m span bridge. The sectional efficiency factors of the spliced U-type sections were analyzed as 0.76∼0.99. It shows that the spliced U-type sections ar of a superior structural efficiency in contrast to the average sectional efficiency factor of 0.66 value in the I-type girders.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1992.10a
• /
• pp.73-78
• /
• 1992

It would be much effective that single column type pier is used in concrete slab bridges rather than gravity type pier is used. To determine the longitudinal bonging moment in concrete slab bridges supported by single column type piers, the concept of effective width is applied. By elastic plate theory cooperated with finite element method, the distribution of the longitudinal moment of the slab supported by single column type piers is studied. The main variables are span, width, and thickness of the slab and column section size. Then the analytical results obtained are summarized and analysed to evaluate the maximum longitudinal negative moment by simple beam analysis.