• Steel and Composite Structures
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• v.45 no.6
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• pp.797-818
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• 2022

Steel-precast ultra-high-performance concrete (UHPC) composite beams with demountable high-strength friction-grip bolt (HSFGB) shear connectors can be used for accelerated bridge construction (ABC) and achieve excellent structural performance, which is expected to be dismantled and recycled at the end of the service life. However, no investigation focuses on the demountability and reusability of such composite beams, as well as the installation difficulties during construction. To address this issue, this study conducted twelve push-out tests to investigate the effects of assembly condition, bolt grade, bolt-hole clearance, infilling grout and pretension on the crack pattern, failure mode, load-slip/uplift relationship, and the structural performance in terms of ultimate shear strength, friction resistance, shear stiffness and slip capacity. The experimental results demonstrated that the presented composite beams exhibited favorable demountability and reusability, in which no significant reduction in strength (less than 3%) and stiffness (less than 5%), but a slight improvement in ductility was observed for the reassembled specimens. Employing oversized preformed holes could ease the fabrication and installation process, yet led to a considerable degradation in both strength and stiffness. With filling the oversized holes with grout, an effective enhancement of the strength and stiffness can be achieved, while causing a difficulty in the demounting of shear connectors. On the basis of the experimental results, more accurate formulations, which considered the effect of bolt-hole clearance, were proposed to predict the shear strength as well as the load-slip relationship of HSFGBs in steel-precast UHPC composite beams.

• Magazine of the Korea Concrete Institute
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• v.6 no.5
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• pp.123-130
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• 1994

In this paper, a development of composite bridge decks was proposed for design of civil and architectural structures to reuse the empty cans and plastics etc. The experimental specimens were made of rigid foamed urethane taking advantage of corrosionlessness in steel bridge decks, and simplicity in the field construction. 'Therefore, introducing the empty cans into the rigid foamed urethane, this experimentation have been carried out to demonstrate and evaluate the structural behavior by means of loading and vibration tests in composite bridge decks. Consequently, it was possible that had a good effect on the structural behavior by absorbing the strain due to the low elasticity of rigid foamed urethane, and not influence to cans in composite bridges.

• Steel and Composite Structures
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• v.18 no.6
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• pp.1479-1492
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• 2015

This study evaluated the localized stress condition of the real corroded deck surface of an orthotropic steel bridge because severe corrosion damage on the deck surface and fatigue cracking were reported. Thus, a three-dimensional finite element (FE) analysis model was created based on measurements of the corroded orthotropic steel deck surface to examine the stress level dependence on the corrosion condition. Based on the FE analysis results, it could be confirmed that a high stress concentration and irregular stress distribution can develop on the deck surface. The stress level was also increased by approximately 1.3-1.5 times as a result of the irregular corroded surface. It was concluded that this stress concentration could increase the possibility of fatigue cracking in the deck surface because of the surface roughness of the orthotropic steel bridge deck.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.519-524
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• 2002

The long span PSC deck of composite girder bridge should be needed in order to improve the endurance and to simplify the structure of the steel bridge. However, there have been few domestic research activities about long-span PSC decks for the steel bridges with a small number of girders. In this study, a literature survey is performed to develop a new deck system for the steel bridge with a small number of girders. By considering the characteristics of a small number of girders bridge system, a cast-in-place long span PSC deck is proposed for a small number of girders bridges. To examine structural behavior and safety of the proposed PSC deck, the real scale partial models of the deck(12m$\times$3.2m) are tested under the static loading. In the test, the failure mode and behavior of each specimen, and ultimate load carrying capacity of the proposed PSC deck are identified.

• Steel and Composite Structures
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• v.45 no.1
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• pp.119-131
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• 2022

Due to the complexity of the structure and the limits of classical SEA, a combined SEA approach is employed, with angle-dependent SEA in the low- and mid-frequency ranges and advanced SEA (ASEA) considering indirect coupling in the high-frequency range. As an important component of the steel box girder, the dynamic response of an L-junction periodic ribbed plate is calculated first by the combined SEA and validated by the impact hammer test and finite element method (FEM). Results show that the indirect coupling due to the periodicity of stiffened plate is significant at high frequencies and may cause the error to reach 38.4 dB. Hence, the incident bending wave angle cannot be ignored in comparison to classical SEA. The combined SEA is then extended to investigate the vibration properties of the steel box girder. The bending wave transmission study is likewise carried out to gain further physical insight into indirect coupling. By comparison with FEM and classical SEA, this approach yields good accuracy for calculating the dynamic responses of the steel box girder made of periodic ribbed plates in a wide frequency range. Furthermore, the influences of some important parameters are discussed, and suggestions for vibration and noise control are provided.

• Journal of Korean Society of Steel Construction
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• v.17 no.3 s.76
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• pp.317-324
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• 2005

The specially orthotropic plate theory is used to analyse three-span continuous composite slab bridges with elastic intermediate supports. A method of calculating the natural frequency corresponding to the first mode of vibration of beams and tower structures, with irregular cross sections and with arbitrary boundary conditions, was developed and the result of application of this method to the three-span continuous composite slab bridges with elastic intermediate supports is presented. This type of bridge represents either concrete or sandwich type three-span bridge on polymeric supports for passive control or on actuators for active control. Any method may be used to obtain the deflection influence surfaces needed for this vibration analysis. The finite difference method is used for this purpose in this paper. The influence of flexural stiffnesses and the modulus of the foundation are studied.

• Journal of Korean Society of Steel Construction
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• v.9 no.3 s.32
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• pp.441-455
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• 1997

The need for rehabilitation of the existing bridges is a growing concern in many countries and has been emphasized in various research reports and publications. Many bridges constructed between 1960s and 1970s in Korea were designed for relatively light traffic volumes, speeds and the weight, thus they are inadequate for the present traffic conditions. This together with some design deficiencies, has resulted in deficiencies of various degrees of many bridges. One strengthening method which has significant advantages is the application of external post-tensioning tendons. This paper presents an example of three span continuous composite bridge strenghtened by application of external post-tensioning.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.2
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• pp.211-216
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• 2002

A steel plate-concrete composite slab with pyramidal shear connectors, named TSC composite slab, is expected to have sufficient bending strength and flexural rigidity for loads during and after construction. Fatigue problems play an important role in designing composite slab as bridge decks under traffic conditions. In this paper, a series of fatigue tests was carried out on TSC beam specimens under various loading conditions, in order to evaluate the fatigue strength of TSC composite slabs. The results are as follows : (1) the fatigue failure of TSC composite beams results from the tensile fracture of bottom steel plate and shear connector, and (2) fatigue strength of the steel plate for two million cycles can be estimated to be $1144kgf/cm^2$ from the S-N curves.

• Journal of Korean Society of Steel Construction
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• v.14 no.6
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• pp.691-699
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• 2002

A study on the evaluationof the proper spacing and required bending rigidity of cross beams in composite multiple I-girder bridge without lateral and sway bracing system was performed. For the purpose, a two-lane 40m simple span and 40+50+40m continuous sample bridge with four girders was designed. For the sample bridges, structural analysis under the design loads including dead load before and after composite, live load, and seismic loads has been performed. The material and geometric nonlinear analysis under dead load before composite has also been performed to evaluate lateral buckling strength of the steel-girder-cross beam grillage. Based on the two phase anlayses, proper spacing and bending righidity of cross beams were proposed.

• Journal of Korean Society of Steel Construction
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• v.10 no.4 s.37
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• pp.577-587
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• 1998

The influences of high speed train on the dynamic responses of steel composite railway bridges are investigated. The bridge system which has two I-girder and several cross beams is modeled with plate and frame elements. With assumption of concrete slabs are fully connected with steel girders, the offset between slabs and girders is modeled using constraint equation. The track system is modeled using beams on elastic foundation theory. And, the TGV train model is developed in 2-dimension considering bouncing and pitching motion. And braking action of vehicle is considered using speed dependent braking function. To investigate the behavior of bridges due to moving trains, parametric studies on the variation of natural frequency of bridge, speed parameter, vehicle modeling method, braking action of train, etc are performed.