• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.68.2-68.2
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• 2009

• Structural Engineering and Mechanics
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• v.47 no.1
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• pp.59-73
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• 2013

The Xiaolan channel super large bridge is unique in style and with greatest span in the world with a total length of 7686.57 m. The main bridge with spans arranged as 100m+220m+100m is a combined structure composed of prestressed concrete V-shape rigid frame and concrete-filled steel tubular flexible arch. First of all, the author compiles APDL command flow program by using the unit birth-death technique and establishes simulation calculation model in the whole construction process. The creep characteristics of concrete are also taken into account. The force ratio of the suspender, arch and beam is discussed. The authors conduct studies on the three-plate webs's rule of shear stress distribution, the box girder's longitudinal bending normal stress on every construction stage, meanwhile the distribution law of longitudinal bending normal stress and transverse bending normal stress of completed bridge's box girder. Results show that, as a new combined bridge, it is featured by: Girder and arch resist forces together; Moment effects of the structure are mainly presented as compressed arch and tensioned girder; The bridge type brings the girder and arch on resisting forces into full play; Great in vertical stiffness and slender in appearance.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1997.10a
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• pp.95-102
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• 1997

Jointless bridge is a new construction method applicable to bridge of short length. In the jointless bridge expansion of superstructure due to thermal effect was absorbed in the flexible pile-type abutment in stead of expansion joint in the conventional bridges. By removing expansion joint, it retards deterioration and extends life time of bridge. In this paper, jointless bridge of steel box girder type was studied through finite element analysis. Stress variations of superstructure and pile due to thermal effect was studied for the two span continuous integral bridge of 80m length and the results of analysis was presented.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.3147-3155
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• 2011

Railway bridges are highly susceptible to resonance due to the equidistant axle load with constant speed of train. Thus, it is inevitable verify dynamic characteristics and quantities against dynamic guidelines. Recently, various new-type bridges are developed and applies to medium span length between 30m and 40m. However, just steel box girder bridge is under review for span length between 45m and 50m without development any new technologies. This study investigate the dynamic properties and safety of steel box railway bridge having span length 45m in alternative girder hight and kind of ballast. Numerical analysis is performed time series analysis by mode superposition using calculated natural vibration frequency and mode after carry out a free vibration analysis and extract modal parameter to higher modes. The results are then compared to various dynamic stability standards toward target bridge's dynamic stability analysis. The result of this study is expected as a reference for design railway bridges.

• Journal of Korean Society of Steel Construction
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• v.11 no.1 s.38
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• pp.79-88
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• 1999

Damages of a steel box girder bridge are detected using neural networks. Damage detection using neural networks has increasing momentum in structural engineering. It is a new effort to overcome the limitations of the conventional analytical approaches and applied to the damage detection of a steel box-girder bridge. Data sets for training neural networks are obtained from the acceleration response of the bridge under moving load. Finite element model is first defined and damages of 5, 10, 15 and 20% are assumed in the model. Not only the trained damages but untrained damages are detected in the assessment stage. The untrained damages can be detected with acceptable errors. Because the number of damaged locations are limited to a few parts, more researches are needed to put this technique into practice.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.12
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• pp.7350-7356
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• 2014

To study the reasonable design thermal loads, a steel box girder bridge specimen, which has no concrete slab, was manufactured with real size dimensions. The temperature data was obtained at the web and diaphragm using thermo gauges that were attached according to height. In the hottest day, the temperature differences between the top and bottom of the bridge model were calculated. The temperatures in the actual bridge were measured and the temperature of the bridge specimen was compared. The temperature gradient models were proposed in both the web and the diaphragm. The proposed models showed a correlation of approximately 95.8% compared to the Euro code. This study can provide basis data for temperature-load design in the nation.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1536-1541
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• 2011

Simple girder bridges are more economical than commonly used PSC box girder bridges in high-speed railway construction, if they secure the riding stability. In this study, the dynamic behavior and riding stability of the newly developed precast V-girder bridge are analyzed. The dynamic moving load analysis is used including two train load case : the KTX train and freight train.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.4
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• pp.139-144
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• 1999

Based on the recent developments of the reliability-based structural analysis and design as well as the extending knowledge on the probabiliistic characteristics of load and resistances, the probability based design criteria have been successfully developed for many standards. Since the probabilistic characteristics depend highly on the local load and resistances, it is recognized to develop the design criterion compatible with domestic requirements. The existing optimum design methods, which are generally based on the structural theory and certain engineering experience, do not realistically consider the uncertainties of load and resistances and the basic reliability concepts. This study is directed to propose a optimum design based Expected Total Cost Minimization on P.S.C Box Girder Bridge system which could possibly replace optimum design based traditional provisions of the current code, based on the Neldel-Mead Method reliability theory.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.193-200
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• 2001

In this study, the methodology to develop a data model for steel box girder bridge based on STEP part 104 is presented. The concept of STEP and the schema of part 104 are briefly reviewed, and then the procedure of data model standardization is described. A new data model for steel box girder bridge is developed by incorporating with not only the geometric and topological representation schema of the part 42 but also the representation structure information of the part 43 and the detailed finite element analysis information of the part 104. The prototype of integrated finite element analysis(FEA) system by interfacing STEP physical file is also presented. The applicability of developed data model for FEA is verified by preprocessor system of FEA.

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