• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.04a
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• pp.77-84
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• 1998

The finite strip method is presented for the analysis of steel deck bridges. Like the Pelikan-Esslinger design method for the steel deck bridges, steel deck is treated as an equivalent orthotropic plate. In the presented method, the deck is discretised by finite strips in the longitudinal direction and the effect of main girder or floor beam deflection can also be accounted for. In this method, the terms of harmonic series at elastically support such as transverse floor or diaphragm in steel deck become coupled. Solutions of this method are compared with other available analytical and numerical solution, and good agreement is observed.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1569-1576
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• 2011

To install heavy structures in the railway bridges, crane methods or launching methods using temporary structure have been applied. These methods are uneconomical because working yard is required, temporary cut of rail system, etc. In this study, various construction methods has been developed which are suitable to the filed conditions. In the case of simple span structure like plate girder bridges, the girder is loaded to troy system at the working yard and then transferred to the working place. To lift and lower the girder system, a new transfer system was developed. Different methods each for simple span bridge girder and long span girder were developed and detailed work procedures were proposed. Using these methods, the heavy structures can be installed with simple and safe work procedures and the construction cost and duration can be reduced.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.1
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• pp.94-101
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• 2019

Most of the existing rail structures have undergone a lot of aging since a considerable period of time has passed from completion. In particular, among existing railway bridges, many of the plate girder bridges are older bridges that have lived 40 to 60 years or more. Since the treadmill is directly connected to the girder without the ballast, the running load of the vehicle is directly transmitted to the bridge. Therefore, the shock and noise applied to the bridge are larger than those of the ballast bridge, and the dynamic shock and vibration are also relatively large. Therefore, it is very urgent to develop appropriate maintenance, repair and reinforcement technology for existing steel plate bridge. In this study, the authors introduced the characteristics of embedded rail (ERS) developed for improving the performance of the existing plate girder bridge and the techniques solving the vibration and noise problems. In order to evaluate the vibration and noise reduction performance of ERS, a non-ballast plate girder bridge with 5m length of sleepers installed and a plate girder bridge with ERS were fabricated. And, then, the vibration response generated under the same excitation condition was measured and analyzed. Also, the radiated noise analysis was performed using the vibration response data obtained from the experiment as the input data of the acoustic analysis model. As a result of experiments and analyses, it was confirmed that the plate girder bridge's vibration using ERS was reduced by 15.0~18.8dB and the average noise was reduced by 7.7dB(A) more than the non-ballast bridge.

• Proceedings of the KSR Conference
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• 2002.10b
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• pp.1080-1085
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• 2002

A dynamic characteristics of existing steel plate girder railway bridges without ballast were investigated from the finite element analysis. Span lengths, types of vehicle and running speeds are selected as parameters for analyses. For more exact analysis, it was adopted that 3-dimensional bridge models and wheel loads were produced by averaging field measured wheel loads of running vehicles at various speeds. Dynamic vertical deflections, dynamic amplification factors and vertical accelerations of bridges having 9m, 12m and 18m span length were investigated and compared with the limit values specified in Korean railway bridge specification.

• Journal of Korean Society of Steel Construction
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• v.11 no.2 s.39
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• pp.213-222
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• 1999

Elastic-plastic methods have been used for the better prediction of the actual behavior of continuous-composite plate girder bridges in the overload and maximum load analysis. The structural evaluation using ALFD(Alternate Load Factor Design) uses the elastic-plastic analysis. The plastic rotations that remain after the load is removed can be occurred by the yielding locations of the maximum moment section. This situation can occur due to the residual stresses even if the moment is below the theoretical yield moment. The local yielding causes positive automoments that assure elastic behavior under subsequent overloads. In this study, the automoments at the piers occurred due to the unit plastic rotations and other locations were calculated by the conjugate-beam method and three-moment equation, using the nine design span with progressively smaller pier sections. The automoments were determined by the developed computer programs in this study in which the moments and plastic rotations from the continuity and moment-inelastic rotation relationships must be equal. And also the ratings of 3-span continuous composite plate girder bridges with non-compact section were carried out according to the Korean Highway Bridge Specification.

• Journal of Korean Society of Steel Construction
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• v.16 no.6 s.73
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• pp.725-736
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• 2004

A new type of girder, called steel-confined prestressed concrete girder (SCP girder), has been developed, which maximizes the structural advantages of concrete, steel, and PS tendon, and improves on the shortcomings of steel plate girder, PSC I-girder, and preflex girder bridge for use in the construction of middle- or long-span bridges. To verify the propriety of design, structural safety, and applicability of this girder, a static load test was carried out (Kim et al.., 2002). Since the main damage typically sustained by steel bridges results from the fatigue caused by the repetition of traffic loads, fatigue safety must therefore be guaranteed in applying the SCP girder in the construction of real bridges. In this study, a fatigue test was carried out to investigate fatigue behavior and provide basic data for fatigue design. Based on the fatigue test, the fatigue safety of the girder was estimated. For the fatigue test, 10-m specimens were designed for a standard-design truckload (DB-24). A static load test was also performed before the fatigue test to analyze the structural behavior of the specimens. After the fatigue test, outer steel plates were removed to observe the condition of the concrete in the girder.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3A
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• pp.305-313
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• 2008

A reliability based calibration of dynamic load allowance (DLA) of highway bridge is performed by numerical dynamic analysis of various types of bridges taking into account of the road surface roughness and bridge-vehicle interaction. A total of 10 simply supported bridges with three girder types in the form of prestressed concrete girder, steel plate girder, and steel box girder is analyzed. The cross sections recommended in "The Standardized Design of Highway Bridge Superstructure" by the Korean Ministry of Construction are used for the prestressed concrete girder bridges and steel plate girder bridges while the box girder bridges are designed by the LRFD method. Ten sets of road surface roughness for each bridge are generated from power spectral density (PSD) function by assuming the roadway as "Average Road". A three dimensionally modeled 5-axle tractor-trailer with its gross weight the same as that of DB-24 design truck is used in the dynamic analysis. For the finite element modeling of superstructure, beam elements for the main girder, shell elements for concrete deck, and rigid links between main girder and concrete deck are used. The statistical mean and coefficient of variation of DLA are obtained from a total of 100 DLA results for 10 different bridges with each having 10 sets of road surface roughness. Applying the DLA statistics obtained, the DLA is finally calibrated in a reliability based LRFD format by using the formula developed in the calibration of OHBDC code.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.240-245
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• 2005

There has been a strong demand on more economic and lower depth girder bridges for short and medium span range, PRECOM, which is a new type steel-concrete composite girder, has been developed to realize a more economic bridge system with a lower depth girder. In the PRECOM girder bridge, a steel plate girder is simply supported and then concrete form is hung to girder. Thus, the self-weight of the concrete is loaded to the steel girder. To increase the resistance of concrete in the lower casing against tensile stress, compressive force is introduced by prestressed tendon To evaluate the manufacturability and performances of the completed bridge, four 15-m girders and a bridge specimen with two 20m girders wvere constructed. The camber during the construction and introduction of an appropriate compressive force was evaluated. Dynamic data were obtained through the modal testing of the completed girders. Static loading test was also conducted to examine cracks and evaluate the decrease in stiffness and failure behavior under extreme conditions.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.401-410
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• 2007

Form the application of long rail system the non-ballast steel plate bridges, fatigue strength increase and rail noise reduction can be expected. This is mainly form the reduction of the rail impact at the rail joint locations which already made to behave together from welds. In the high speed rail, application of long rail system is essential because without long rail system, the required serviceability level can not be achieved. But even with this long rail systems, the thermal expansion from the girder can not be absorbed in the normal bearing systems, and these expansion cause between girder and rail. Also unexpected rail buckling and fracture through rail thermal tension may happen. It was found through numerical analysis and field measurement that these problems can be avoided by semi-fixed bearing system. In this study, the benefits of non-ballast plate bridge through long rail system, especially at the point of girder stability, girder stiffness increase and bearing maintenance will be reviewed.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.601-608
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• 2003

A new type of bridge superstructures referred to as Steel-confined Prestressed Concrete Girder (SCP Girder) was developed, which is composed of concrete, steel plate, and prestressing tendon. The girder may maximize structural advantages of these components : thus, long span bridges with low height girder may be constructed. For the effective design and fabrication of the girder, the design software program was developed and the process of fabrication established. The experimental girder designed using the program was manufactured in actual size to confirm the fabric ability of the girder. Propriety of design, structural safety, and applicability of the girder were verified through the load test.