• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.04a
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• pp.128-136
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• 2001

This paper presents an optimum deck and girder system design for minimizing the life-cycle cost (LU) of steel box girder bridges. The problem of optimum LCC design of steel box girder bridges is formulated as that of minimization of the expected total LCC that consists of initial cost, maintenance cost, expected retrofit costs for strength, deflection, and crack. To demonstrate the effect of LCC optimum design of steel box girder bridges, the LCC optimum design is compared with conventional design method for steel box girder bridges design. From the numerical investigations, it may be positively stated that the optimum design of steel box girder bridges based on LCC will lead to more rational, economical and safer design.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.04a
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• pp.154-161
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• 2001

A procedure of the design optimization for steel box girder bridges using micro genetic algorithms(μGA) is developed. The effect of population size is investigated and the efficiency and reliability of μGA is demonstrated in the optimum design of steel box girder bridges. Optimum design problems of steel box girder bridges are formulated, where tile design of concrete slab is based on the USD specifications and steel box girder based on LRFD respectively. Design of optimizations of single-span and 2-span steel box girder bridges are performed with the population size of 5, 40, 80, and 120, respectively The μGA-based optimum design of the 3-span steel box girder bridge is compared with SQP results.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.688-693
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• 2007

Nowadays various studies related with superstructure of bridges are developed and they pursuit more effective section of bridges superstructure, material and economical application of composite materials. CFT structure(Concrete Filled Steel Tubular Structure) is developed type of composite structure that concrete is filled with steel box, and the deformation of the member, stiffness and internal force will be improved by confinement effect of steel box and concrete. This paper introduces new type of girder, CFTA girder( Concrete- Filled and Tied Steel Tubular Arch Girder) which is combined with traditional CFT structure,arch effect and prestress through carrying out the structural analysis by computer programs. The computer programs which is used are ABAQCS and MIDAS, and the 12.2m girder which is applied same load and prestresses is analyzed and compared the results respectively.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10b
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• pp.680-685
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• 1998

Prestressed concrete I-girders were used in the bridge applications in the early 1950s. During the last four decades, the most widely used girder length of bridges have been below 30meters. The main objective of this study is to develope the alternative section for long span bridge which exceed 40 meters. The developed Bulb-Tee girder has a wide bottom flange to enhance the compressive strength and to allow placement of a large number of strands in the bottom flange. New bulb-tee shaped PSC girder sections are proposed in this paper. Splicing the technique for long span bridge girder to reduce the self weight is also proposed.

• Advances in concrete construction
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• v.3 no.2
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• pp.113-126
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• 2015

Holed-Incrementally Prestressed Concrete (H-IPC) girders are designed using the following new design concepts. At first, web openings reduce the self-weight of the girder, and also diffuse prestressing tendon anchorages. The reduced end anchoring forces decrease the web thickness of the end sections. Additionally, precast technology help to improve the quality of concrete and to reduce the construction period at the site. For experimentally verification, two 50 m full-scale H-IPC girders are manufactured with different concrete strength of 55 MPa and 80 MPa. The safety, stiffness, ductility, serviceability and crack development of H-IPC girder are measured and compared with each other for different strengths. Both girders show enough strength to carry live load and good stiffness to satisfy the design criteria. The experimental result shows the advantages of using high strength concrete and adopting precast girder. The test data can be used as a criterion for safety control and maintenance of the H-IPC girder.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.538-544
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• 2006

This paper is to investigate the dynamic characteristics of prestressed concrete (PSC) girder that has been spliced with precast box segments. A 20 m long full-scale spliced precast concrete box railway girder was fabricated and tested to identify its dynamic properties against a monolithic girder. The monolithic girder has the same geometric and material properties with respect to the spliced girder. Dynamic parameters including natural frequency, mode shape, and damping ratio were identified using the a digitally controlled exciter. Modal analyses were performed based on three-dimensional finite element models, and the calculated modal parameters were compared with test results. Finally, the characteristic decrease of natural frequency due to damage for each girder has been examined after the load test.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.287-290
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• 2008

Resistance to lateral torsional buckling of steel I-girder (open section) is a very important design requirement. But, most studies of steel I-girder with corrugated webs were invested in shear behavior. Untill now, most studies about Lateral torsional buckling of I-girder with corrugated webs have been based on Lindner.J's study (Lateral torsional buckling of beamswith trapezoidally corrugated webs,1990). the study includes that the pure torsional constant of I-girder with corrugated webs $J_{cor}$ doesn't different from that of I-girder with flat webs. This paper pesents pure torsional constant of I-girder with corrugated webs by using finite element anaysis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.6
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• pp.143-153
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• 2006

The paper presents the results of a study on improvement in flexure capacities of continuous prestressed steel I-girder with section increasement at internal supports. After tensioning, the field experiment on prestressed steel I-girder has been performed in the various aspects of prestressed I-girder introducing section increasement at internal supports, tendon profile.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.186-189
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• 2003

Precast Segmental method was developed in germany 1950s. This method has been adoptted in long span girder mainly owing to easy construction effect. But, so far, The limit exists that this method is constructed in a portion of span and hard conveyance and foundation. This study was performed to analysis behavior difference of two rectanglar section girder, spliced girder that was jointed 5-sliced 0.8m segment and monolithic girder that was produced in one body 4m span

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1997.10a
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• pp.80-86
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• 1997

Recently, the box-girder bridge became quite popular because of the effectiveness of the box section against torsional deformation, and the finite element method has been one of the powerful and versatile method for obtaining the solution of box-girder bridge. The finite element method is used to solve a box girder which is built up with flat plates such as flanges, webs and diaphragm, and box girder is idealized by 8-nodes 2-dimensional isoparmetric finite element. To investigate the stress of diaphragm, substructure analysis is performed with two Parameters which are the location of support and slope of web.