• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.499-504
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• 2003

Future bridge decks must have high load-resistance capacity as well as fatigue strength to withstand the increase in traffic loading and the increase in span length between girders due to the decrease in the number of main girders. Steel-concrete composite bridge decks may be proper deck types to satisfy such requirements. To promote the application of composite bridge decks, a rational process to predict and evaluate the fatigue behavior of steel concrete composite bridge deck is required. Various types of steel-concrete composite bridge decks have been developed in many countries. In this study, combining advantages of the existing composite deck types, a new type of composite bridge deck is proposed. An experimental study is performed to examine the fatigue behavior of the proposed composite bridge deck. This composite bridge deck consists of corrugated steel sheet, welded T-beams, stud-type shear connectors and reinforced concrete filler. The fatigue tests are conducted under four-point bending test with three different stress ranges in constant amplitude. The fatigue category of the fillet welding between corrugated steel sheet and the T-beam is evaluated based on the S-N data obtained from the experiment.

• International Journal of Highway Engineering
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• v.15 no.1
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• pp.37-45
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• 2013

PURPOSES: This study is to analyze different vehicle load effects for a bridge design of South and North Korea in order to prepare a common design specification and to secure the safety of transportation when the highway bridges of South and North Korea use together. METHODS: Based on the literature review, this study considers vehicle load effects by comparing different characteristics of the standard vehicle and other differences of the bridge design specification between South and North Korea. And structural modeling of three-span continuous PSC Beam Bridge are analyzed and the bridge capacity according different vehicle loads of South and North Korea is evaluated. RESULTS: The result of this study indicates that the bridge capacity and the design vehicle weight of North Korea are smaller than the bridge capacity and the design vehicle weight of South Korea. Also this study demonstrates that the design vehicle array and other characteristics of North Korea are very different than the design vehicle array and other characteristics of South Korea. CONCLUSIONS: It is expected that the outcomes of this study can be useful in the set-up of South-North Bridge Specification because similar previous studies are rarely found.

• Geomechanics and Engineering
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• v.7 no.2
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• pp.201-212
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• 2014

Due to the sea-crossing bridge span is generally large and main pier pile foundations are located in deep water and carry large vertical load, sea-crossing bridge main pier pile foundations bearing mechanism and load deformation characteristics are still vague. Authors studied the vertical bearing properties of sea-crossing bridge main pier pile foundations through pilot load tests. Large tonnage load test of Qingdao Bay Bridge main pier pile program is designed by using per-stressed technique to optimize the design of anchor pile reaction beam system. Test results show that the design is feasible and effective. This method can directly test bearing capacity of main pier pile foundations, and analysis bearing behaviors from test results of sensors which embedded in the pile. Through test study the vertical bearing properties of main pier pile foundation and compared with the generally short pile, author summarized the main pier pile foundations vertical bearing capacity and the main problem of design and construction which need to pay attention, and provide a reliable basis and experience for sea-crossing bridge main pier pile foundations design and construction.

• Structural Engineering and Mechanics
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• v.11 no.3
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• pp.259-272
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• 2001

The impact behavior of a multigirder concrete bridge under single and multiple moving vehicles is studied based on correlated road surface characteristics. The bridge structure is modeled as grillage beam system. A 3D nonlinear vehicle model with eleven degrees of freedom is utilized according to the HS20-44 truck design loading in the American Association of State Highway and Transportation Officials (AASHTO) specifications. A triangle correlation model is introduced to generate four classes of longitudinal road surface roughness as multi-correlated random processes along deck transverse direction. On the basis of a correlation length of approximately half the bridge width, the upper limits of impact factors obtained under confidence level of 95 percent and side-by-side three-truck loading provide probability-based evidence for the evaluation of AASHTO specifications. The analytical results indicate that a better transverse correlation among road surface roughness generally leads to slightly higher impact factors. Suggestions are made for the routine maintenance of this type of highway bridges.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.7
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• pp.32-39
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• 2011

FPS(Filament Power Supply), one of the KSTAR NBI(Neutral Beam Injections) is implemented by full-bridge DC/DC converter. NBI heating device for KSTAR(1.5MW) is developed for heating an ion source of plasma in KSTAR tokmak. The full-bridge DC/DC converter is applied to FPS for isolation with input and output. And FPS is operated with PWM control method which is the most usual method. In this paper, NBI FPS of 4.8kW is simulated by using the PSIM 6.0. And the full-bridge DC/DC converter using IGBTs is fabricated to demonstrate it. The processor DSP 28335 is implemented for digital control.

• Smart Structures and Systems
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• v.14 no.4
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• pp.501-516
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• 2014

The rocking pier system (RPS) allows the columns to rock on beam or foundation surfaces during the attacks of a strong earthquake. Literatures have proved that seismic energy dissipated by the RPS through the column impact is limited. To enhance the energy dissipation capacity of a RPS bridge substructure, frictional hinge dampers (FHDs) were installed and evaluated by shaking table tests. The supplemental FHDs consist of two brass plates sandwiched by three steel plates. The strategy of self-centering design is to isolate the seismic energy by RPS at the columns and then dissipate the energy by FHDs at the bridge deck. Component tests of FHD were first conducted to verify the friction coefficient and dynamic characteristic of the FHDs. In total, 32 shaking table tests were conducted to investigate parameters such as wave forms of the earthquake (El Centro 1940 and Kobe 1995) and normal forces applied on the friction dampers. An analytical model was also proposed to compare with the tested damping of the bridge sub-structure with or without FHDs.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.311-316
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• 2007

The improvement of speed and ride comfort requires a very horizontally and vertically rigid and non-flexible alignment. It is inevitable to construct many bridges depending on the topography of landscapes and obliged to lay turnouts on the bridges. In that case, special considerations have to be taken into account, i.e. permissible stresses of turnout components and limitations of displacements of bridge and turnouts. In this studies, numerical analyses for turnout/bridge interaction are carried out using commercial program LUSAS. The target of analytical model is the turnout layed near Pyeongrae-Hopyeng station on Kyeongchun line. The lead rail, stock rails, and the bridge are modelled using beam elements. Fasteners and ballast resistances are modelled using bi-linear spring elements. The turnout behaviors are investigated by varying the parameters such as span length of bridge, spring coefficients, and thermal loads.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1478-1485
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• 2010

In this paper, the nonlinear dynamic response of Vehicle-Bridge interaction with the coupled equations of motion including nonlinear Hertzian contact is presented. The moving train model is chosen to have 10 degrees of freedom (DOF). The bridge is modeled as 2D Euler-Bernoulli beam element with 4 DOF for each element, two for rotations and another two for translations. The nonlinear Hertzian contact is used to simulate the interaction between vehicle and bridge. Base on the relationship of wheel displacement of the vehicle and the vertical displacement of the bridge in Hertzian contact, the coupled equations of motion of the whole system is derived. The convenient formulation was encoded into a computer program. The contact forces, contact area and stress of the rail surface were also computed. The accuracy and efficiency of the proposed program are verified and compared with exact analytical solution and other previous studies. Various numerical examples and parametric studies have demonstrated the versatility and applicability of the proposed program.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.217-222
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• 2005

We come to know that recent seismic design is used in the railway bridge design by several analysis methods. The result of the analysis in each method is very different from each other, so very weak structures or very exaggerated structures are designed for earthquake. In this paper, by conducting seismic analysis of 25m PSC beam bridge mainly used in railway bridge, we compared and analyzed the difference of the result of the analysis methods. As a result, we could find that moment varies from $53\%\;to\;151\%$ depending on geometrical shape of bridge or seismic analysis method.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.63-66
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• 2008

The bridge deck section composed of a concrete slab resting on two I-beam girders are known to be susceptible to flutter instability and vortex shedding. Moreover, the cable stayed bridge in construction is more vulnerable to wind rather than in service when the free cantilever construction method is applied. This paper describes the effect of the dynamic wind loads on the bridge during construction and the effect of alternative temporary stabilizing measures. Therefore, a series of wind tunnel tests and numerical analysis were carried out to determine if any countermeasures were required.