• Proceedings of the Korea Concrete Institute Conference
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• 1993.10a
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• pp.195-200
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• 1993

This paper develops practical and realistic reliability models and methods for the evalusion of system reliability and system reliability-based rating of R.C box-girder bridge superstructures. The precise prediction of reserved carrying capacity of bridge as a system is extremely difficult expecially when the bridges are highly redundant and significantly deteriorated or damaged. This paper proposes a new approach for the evaluation of reserved system carrying capacity of bridges in terms of equivalent system-strength, which may be defined as a bridge system-strength corresponding to the system reliability of the bridge. This can be derived from an inverse process based on the concept of FOSM form of system reliability index. The strength limit state models for R.C box-girder bridges suggested in the paper are based on the basic bending and shear strength. and the system reliability problem of box-girder superstructure is formulated as parallel-series models obtained from the FMA(Failure Mode Approach) based on major failure mechanism or critical failure states of each girder. AFOSM and IST(Importance Sampling Technique) simulation algorithm is used for the reliability analysis of the proposed models.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.04a
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• pp.313-321
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• 1999

To design steel box girder bridge, designers have taken the classical load distribution coefficient methods. Due to the rapidly developing computer technique, steel box girder bridge is simply modeled as grillage method for analyzing the girder, or as fully finite element method for more accurate and detailed analysis. Recently, cruciform space frame method is developed for modeling and analyzing it more simply and easily compared with finite element method. So, this study for the examination of upper methods' characteristics loaded unit moment load and analyzed the distortional deflection with shell element method and cruciform space frame method, and for three span three girder steel box bridge, loading DB-24 loads, analyzed it by upper methods and compared the results.

• Steel and Composite Structures
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• v.34 no.3
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• pp.423-440
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• 2020

In the recent years, steel box girder bridges have been extensively used due to high bending stiffness, torsional rigidity, and rapid construction. Therefore, researches related to this girder bridge have been widely conducted. This paper investigates the effect of residual stresses and geometric imperfections on the load-carrying capacity of steel box girder bridges spanning 30 m and 50 m. A three - dimensional finite element model of the steel box girder with a closed section was developed and analyzed using ABAQUS software. Nonlinear inelastic analysis was used to capture the actual response of the girder bridge accurately. Based on the results of analyses, the superimposed mode of webs and flanges was recommended for considering the influence of initial geometric imperfections of the steel box model. In addition, 4% and 16% strength reduction rates on the load - carrying capacity of the perfect structural system were respectively recommended for the girders with compact and non-compact sections, whose designs satisfy the requirements specified in AASHTO LRFD standard. As a consequence, the research results would help designers eliminate the complexity in modeling residual stresses and geometric imperfections when designing the steel box girder bridge.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.625-630
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• 2002

PSC box girder is widely used in a domestic bridge and overpass, etc., therefore, the design and construction technique for the PSC box girder is developing day by day. Even if it were so, however, the design for anchorage zone in PSC box girder has depended on common sense and empirical results. And it is the current situation that the designer has difficulty due to inadequacy of provisions in the domestic design code and lack of understanding for behavior of anchorage zone. Besides, the design based on Leonhardt's method is being done in general, but the design may be various even for the same structure because of the difference in a way of applying. In this paper, therefore, anchorage zone in PSC box girder bridge is analyzed and designed by using strut-tie model. Adequacy for the application of strut-tie model is verified by comparison with the way used in current design practice, and this study presents that strut-tie model can be a rational and an economical design than current design methods.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.591-596
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• 2001

In case of continuous steel box-girder bridges, the magnitude of the longitudinal tensile stress on concrete in internal support is larger than the tensile strength of concrete. In this paper, the parametric study was performed to present the effective magnitude of the longitudinal prestress for reducing the longitudinal tensile stress to decrease under the tensile strength of concrete. The parametric study is conducted with changing the steel box-girder section and the span length of bridge. Three dimensional finite element analyses are conducted with ABAQUS program. The behavior of the steel box-girder bridge with prestress is investigated through experimental works on a analogous steel box-girder bridge model, and their results are compared with those of analytical studies.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10b
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• pp.701-705
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• 1998

The objective of this study is to develop the practical program which can check the constructible possibility of prestressed concrete box girder bridges for design. Checking constructible possibility is defined as checking the interference of each elements in a PSC box girder bridge and computing the distances of each elements. To check the constructible possibility of a PSC box girder bride, bridge must be modelled using solid in three dimension. By using a 3 dimensional solid modeling system, engineers can get the photo realistic 3D viewing images of the bridge and produce FEM analytic model of it. Users can manipulate their drawings easier and take off quantity of the whole structure and its elements as well as check the constructible possibility of their PSC box girder bridges.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.1157-1162
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• 2000

Transverse stress and longitudinal crack which are induced by temperature difference in box-girder sections and slab of which box-girder is composed have an important effect on endurance and economical efficiency of bridges. The study on longitudinal behavior of bridges which are subject to thermal load is reflected on the design of bridges. But, the study on transverse behavior of bridges has been performed just recently in foreign countries of finding the cause of longitudinal crack and in Korea, has not been tried in spite of large temperature variance due to geographical condition. This study examines temperature distribution feature in box-girder sections and bridge behavior due to thermal load, with measuring temperature distribution and stress of PSC box-girder bridge which is being constructed actually, and investigates appropriateness of design thermal load of highway bridge design code.

• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.7-18
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• 2006

The Purpose of this study is to develop landscape Preference and define elements of difference in landscape preference of the 1-span Steel Box Girder Bridge by Bridge Shape Parameters(BSP) through Design of Experiments. Lately, the 1-span Steel Box Girder Bridge is dominations much component ratio and the Steel Box Girder Bridge has strong Points that is economically Profitable and management has easy when construct. but landscape preference of the 1-span Steel Box Girder Bridge was evaluated low because impression of landscape is being surfeited and dulled. Do to consider optimization in design that give change to Bridge Shape Parameters(BSP) to supplement this shortcoming in this study. Therefore, this study changes Bridge Shape Parameters(BSP) and extract elements that influence in landscape preference of the 1-span Steel Box Girder Bridge. and based on the design that consider landscape Preference of the 1-span Steel Box Girder Bridge, some essential guidelines for rational design of the 1-span Steel Box Girder Bridge suggested.

• Journal of Korean Society of Steel Construction
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• v.15 no.5 s.66
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• pp.489-497
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• 2003

Bridge has to be long-spanned and of simple structure, considering the social environment. As a result of this trend in bridge construction, it is important for the sake of economical efficiency to improve the structural system and increase the life cycle of a bridge. To attain these goals in constructing a steel bridge, the detail analyses based on real structure must be performed. In the steel structure bridge, the parts that are a main focus of interest are the diaphragm and the vertical bracing of the steel box girder support. This study observed the behavior of the diaphragms on the bearings of a closed section steel box girder bridge support, as dead load was increased. Stress variation of the support diaphragms in a steel box girder was considered, and both experimental test and structural analyses were performed to verify the behavior of a composite steel box girder bridge under repair or maintenance.

• 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.