• Proceedings of the Korea Concrete Institute Conference
• /
• 2010.05a
• /
• pp.41-42
• /
• 2010

Newly developed steel-concrete composite girder bridge that comprise a steel girder with a steel box top slab filled with concrete. Compressive strength and bucking resistance of that are high because the concrete was confined to steel. that is economical form because the top of the section substituted partly steel for concrete. This paper provides that conspicuous characteristics of a new type of steel-concrete composite bridge.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2009.05a
• /
• pp.165-166
• /
• 2009

This paper is to research for construction of the longest open toped steel box girder composite bridge using precast concrete deck in the country. This type bridge can bring down the construction costs by reducing the steel's weight used it's girders. And, it also can reduce working hours for construction over 6months by applying the precast deck system. I will introduce the process of construction the longest this type bridge within the country named Seochon Bridge

• Structural Engineering and Mechanics
• /
• v.7 no.3
• /
• pp.241-257
• /
• 1999

This paper presents a procedure to minimize the cost of materials of cable-stayed bridges with composite box girder and concrete tower. Two sets of iterations are included in the proposed procedure. The first set of iteration performs the structural analysis for a cable-stayed bridge. The second set of iteration performs the optimization process. The design is formulated as a general mathematical problem with the cost of the bridge as the objective function and bending forces, shear forces, fatigue stresses, buckling and deflection as constraints. The constraints are developed based on the Canadian National Standard CAN/CSA-S6-88. The finite element method is employed to perform the complicated nonlinear structural analysis of the cable-stayed bridges. The internal penalty function method is used in the optimization process. The limit states design method is used to determine the load capacity of the bridge. A computer program written in FORTRAN 77 is developed and its validity is verified by several practical-sized designs.

• Journal of Korean Society of Steel Construction
• /
• v.12 no.2 s.45
• /
• pp.133-142
• /
• 2000

This study deals with behavior of steel box girder bridges according to the concrete slab casting sequences and sectional types. The time dependent behavior of bridges caused by the differential setting of slab concrete resulting from time gap for each part of slab deck in a sequential placing method produces is analyzed. In correlation studies between girder section types and placing sequences, time dependent effects of concrete creep and shrinkage are implemented in the analytical model proposed in the previous study. Finally, field recommendations in terms of concrete slump and relative humidity are suggested to prevent early transverse cracking of concrete slabs.

• Structural Engineering and Mechanics
• /
• v.54 no.6
• /
• pp.1135-1152
• /
• 2015

Most of current bridge decks are made of reinforced concrete and often deteriorate at a relatively rapid rate in operational environments. The quick deterioration of the deck often impacts other critical components of the bridge. Another disadvantage of the concrete deck is its high weight in long-span bridges. Therefore, it is essential to examine new materials and innovative designs using hybrid system consisting conventional materials such as concrete and steel with FRP plates which is also known as composite deck. Since these decks are relatively new, so it would be useful to evaluate their performances in more details. The present study is dedicated to Hat-Shape composite girder with concrete slab. The structural performance of girder was evaluated with nonlinear finite element method by using ABAQUS and numerical results have been compared with experimental results of other researches. After ensuring the validity of numerical modeling of composite deck, parametric studies have been conducted; such as investigating the effects of constituent properties by changing the compressive strength of concrete slab and Elasticity modulus of GFRP materials. The efficacy of the GFRP box girders has been studied by changing GFRP material to steel and aluminum. In addition, the effect of Cross-Sectional Configuration has been evaluated. It was found that the behavior of this type of composite girders can be studied with numerical methods without carrying out costly experiments. The material properties can be modified to improve ultimate load capacity of the composite girder. strength-to-weight ratio of the girder increased by changing the GFRP material to aluminum and ultimate load capacity enhanced by deformation of composite girder cross-section.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2003.11a
• /
• pp.169-172
• /
• 2003

Time dependent deflections of double composite box girders are investigated based on the on going laboratory experiments scheduled for 3months long. Two of 2-span double composite box girders with 2.5m each span length are cast and time dependent behaviors are measured using 30 strain gages and 2 LVDTs after 5 days' curing. The measured experimental results are compared with the numerical predictions performed based on the one dimensional finite element method adopting beam element. The FEM formulation adopts the time dependent concrete constitutive model which is derived in an incremental format by expanding the total form of stress-strain relation by the first order Taylor series with respect to the reference time. A good agreement between the measured and predicted results are observed and the effects of the bottom concrete placed at the negative moment region of the bridge girder are discussed.

• Steel and Composite Structures
• /
• v.44 no.5
• /
• pp.619-632
• /
• 2022

There are numerous structural details (Longitudinal beam, web plate, U-ribs and I-ribs) in the top and bottom plates of steel box girders, which have significant influences on the longitudinal stress (normal stress) distribution. Clarifying the influence of these structural details on the normal stress distribution is important. In this paper, the ultra-wide steel box girder with large cantilevers of the Jinhai Bridge in China, which is the widest cable-stayed bridge in the world, has been analyzed. A 1:4.5 scale laboratory model of the steel box girder has been manufactured, and the influence of structural details on the normal stress distribution in the top and bottom plates for four different load cases has been analyzed in detail. Furthermore, a three-dimensional finite element model has been established to further investigate the influence regularity of structural details on the normal stress. The experimental and finite element analysis (FEA) results have shown that different structural details of the top and bottom plates have varying effects on the normal stress distribution. Notably, the U-ribs and I-ribs of the top and bottom plates introduce periodicity to the normal stress distribution. The period of the influence of U-ribs on the normal stress distribution is the sum of the single U-rib width and the U-rib spacing, and that of the influence of I-ribs on the normal stress distribution is equal to the spacing of the I-ribs. Furthermore, the same structural details but located at different positions, will have a different effect on the normal stress distribution.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2010.05a
• /
• pp.79-80
• /
• 2010

Age-dependent laboratory tests for a curved composite box girder were carried out to investigate age-dependent effects of concrete on toraional behavior of a curved girder. Time-dependent incremental finite element method predicted the toraional behavior as well as flexural including axial behaviors of the test specimen.

• Journal of Korean Society of Steel Construction
• /
• v.10 no.2 s.35
• /
• pp.233-251
• /
• 1998

This paper deals with the prediction of behavior of composite girder bridges according to the placing sequences of concrete deck. Based on a degenerate kernel of compliance function in the form of Dirichlet series, the time-dependent behaviors of bridges are simulated, and the layer approach is adopted to determine the equilibrium condition in a section. The variation of bending moments along the bridge length caused by the slab casting sequence is reviewed and correlation studies between section types and placing sequences are conducted with the objective to establish the validity of the continuous placing of concrete deck on the closed steel box-girder which is broadly used in practice.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.23 no.4
• /
• pp.343-351
• /
• 2010

Bending and axial compressive stresses are distributed across the whole upper flange of a box girder bridge which has the span-to-depth ratio (B/L) of below 0.5, according to Korea Bridge Design Specifications (Minister of Land, Transport and Maritime Affairs, 2005). Shear lag phenomenon, however, can take place in the construction phase of cable-stayed bridge, in which stresses combining bending moment due to dead weight and cable vertical compression are induced. This study aims to analyze the effective width of flange over which composite stresses are given, which should be calculated during the construction phase of stiffening girder of single plane cable-stayed box girder bridge. The study results indicate that the full width of stiffening girder can be regarded as the effective flange width when the span-to-depth ratio for the deck is below 0.38. In other words, the area, where shear lag is taken into consideration, is larger than the width of box girder in single plane cable-stayed box girder bridges. Therefore, the current practice of considering the full width as the effective flange width regardless of changes of the span-to-depth ratio during the construction stage can produce an unsafe bridge. If the effective flange width is determined according to the single span structural system in the early stage of construction when the span-to depth ratio for the deck is high and composite stresses of every part expect each end of the bridge are calculated, it can result in a safe structural design. Since the span-to-depth ratio gradually decreases, however, it is appropriate to determine the effective width of flange on the basis of the full width and the cantilever structural system.