• Proceedings of the KSR Conference
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• 2005.05a
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• pp.562-567
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• 2005

F.C.M applied from Jin Jung Li to Yang Su Li(660m) in Puk Han River Bridge(1,414m) construction part is a construction method on the double-track construction which is the third section part of work, called Chung Ang Railroad Line(Deok-So${\sim}$Won-Ju). This method is the beginning application on Railroad Bridge. After completing upper slab structure, there are several following works such as setting up ballast, sleepers and laying long rails. So it is important to consider the properties of Railroad Bridge while designing the length of bridge and its single span. After the physical process study the shrinkage and creep of concrete, bending up by prestressing in general PSM bridge, relaxation of tendons as time goes by after post-tension, the conclusion of such a study is applied to the Puk-Han River Bridge in this construction field.

• Journal of the Korean Society of Safety
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• v.27 no.6
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• pp.138-143
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• 2012

In this thesis, the relationship between the load carrying capacity and the transformed impact factor of the highway bridges were studied. The bridges are classified according to superstructures type. The result of the comparison between the load carrying capacity and the transformed impact factor, if the load capacity ratio of 0.57, the transformed impact factor was less in order of RC T-beam bridge, RC slab bridge, PC beam bridge, I-beam bridge. By the regression analysis on these results, the empirical formulae to predict the the load carrying capacity of bridge were suggested.

• Journal of Industrial Technology
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• v.17
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• pp.205-211
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• 1997

The problem of deteriorated highway concrete slab is very serious all over the world. Before making any decision on repair work, reliable non-destructive evaluation is necessary. One of the dependable methods is to evaluate the in-situ stiffness of the slab by means of obtaining the natural frequency. By comparing the in-situ stiffness with the one obtained at the design stage, the degree of damage can be estimated rather accurately. In this paper, the numerical modeling of vibration analysis to three span continuous reinforced concrete bridge with elastic intermediate support is presented.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.107-112
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• 2001

The IPC(Incremental Prestressed Concrete) which is gradually introducing the tensile force by tendons has been recently developed for reducing the effective depth of PSC bridges. As well known, concrete experiences long-term deformation such as creep and drying shrinkage, and the prediction of the long-term behavior of concrete bridges is essential for both safety and serviceability aspects. This paper was analysed the long-term behavior of a continuous 2-span IPC girder bridge taking into consideration of creep, drying shrinkage and the time of tensile force introduction. As results, the shrinkage of slab concrete increases the negative moment at interior support, and the The difference of concrete ages between slab and girder increases the camber. The effect of initial tensile force is larger than the effect of secondary tensile force in the tendons.

• Journal of the Korea Concrete Institute
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• v.11 no.5
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• pp.33-40
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• 1999

An improved finite element modeling technique is proposed for the assessment of load carrying capacity of partially prestressed concrete girder bridges. Based on the finite element method of analysis, shell and frame elements are used to model the slab and girders of the superstructure, respectively. In the modeling of superstructure, the emphasis is placed on the use of rigid link between the middle surface of slab an mid-plane of girder. This paper also includes the comparision of three different equations that are used in the calculation of effective moment of inertia for the partially prestressed concrete girders. Numerical analysis is performed for the unstrengthened and strengthened bridges. The obtained results are compared with those of load test for a prototype bridge. A good agreement is achieved between the numerical solutions by using the proposed method load test results.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.363-366
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• 2005

When widening or repairing concrete deck slab, there is a joint inevitably. However, joining-construction method have following problem, that is the additional stress in existing part of bridge resulting from the specific process of joining-construction and the difference of amount of shrinkage between new and existing bridge. On this study, compared shrinkage stress of the direct joining construction method with the indirect joining construction method, and concluded the proper substitution rate of expansion cement. The rate of replacement was proper at $10\%$. but more than $15\%$, concrete had excessive expansion and weeker compressive strength. The time of placing closure concrete, considering the shinkage stresses and creep, was suitable in $45\~60$ days after placing the new concrete deck slab.

• Steel and Composite Structures
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• v.2 no.6
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• pp.429-440
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• 2002

A finite strip method is developed for fatigue reliability analysis of steel highway bridges. Flat shell strips are employed to model concrete slab and steel girders, while a connection strip is formed using penalty function method to take into account eccentricity of girder top flange. At each sampling point with given slab thickness and modulus ratio, a finite strip analysis of the bridge under fatigue truck is performed to calculate stress ranges at fatigue-prone detail, and fatigue failure probability is evaluated following the AASHTO approach or the LEFM approach. After the failure probability is integrated over all sampling points, fatigue reliability of the bridge is determined.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.10a
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• pp.69-78
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• 1999

The stiffness of slab concrete section is not considered as effective in the existing method of construction for continued steel box girder bridge. Using lifting system and filled concrete, it is possible to make stiffness of slab concrete section effective and improve stiffness of negative moment section. It was proved that the stress of upper flange in positive moment is significantly lower than case of existing method through the stress comparison. This stress difference made possible to rearrange flange thickness and as the result of this rearrangement, the amount of steel and height of girder can be reduced up to 13.23% and 11.5%.

• Proceedings of the KSR Conference
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• 2001.05a
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• pp.369-374
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• 2001

It was estimated that the anti-vibration measures at the source location of railroad are the most active and effective ones. Among CWR(Continuously Welded Rail), elastic rail fastener, floating slab, ballast mat, under sleeper pad, etc. like these various kinds of measures in the source, under sleeper pad as an anti-vibration measure was constructed at the railroad track supporting structures in the Jeon-la Line. In this study, through the field measurement of vibration at the railroad track supporting structures and nearby the ground, the vibration reduction effect of under sleeper pad were evaluated by insertion loss. As a result, vibration reduction effects were 5.0∼12.5㏈ on the concrete slab of the bridge, 3.9∼7.5㏈ on the ground nearby the bridge respectively.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.43-46
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• 2005

Precast prestressed concrete hollow slab bridge is one of segmented bridge which can be long span, so that the structural behavior of joints of adjacent segment should be evaluated by the analysis as well as experiment. In this study, small scaled beam tests were carried out to determine joint shear key shape and restraint stress by prestressing. From the tests and the analysis, it was found that the joint key shape and the restraint stress affect the behavior of segments and the segments which has the height to the width of shear key as 1/3 possess maximum shear resistance.