• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.6
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• pp.617-625
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• 2021

The problems associated with the continuous method of a domestically improved prestressed concrete (PSC) girder and the bending moment of a continuous tendon were studied. Based on the results, a continuous tendon model was proposed that can resist the negative bending moment of an intergirder. This model lowers the anchorage of the continuous tendon as far as possible under the girder, and extends the tendon section arranged under the girder. This method reduces the PS's bending moment in the middle of the span, but maximizes it in the intergirder. This continuous tendon model can offer a suitable method for continuity before manufacturing a composite, which requires a higher design bending moment in the intergirder than in the middle of the span.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.4
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• pp.135-143
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• 2004

In this paper, 6 span SCP continuous girder bridge's structural behavior were studied by analytic and experimental method To study structural behavior of SCP girder, we used PSC theory and steel girder theory. To examine slab concrete crack, concrete stress, and fatigue stress of steel, we achieved a static load and fatigue test. In the result, 6 span SCP girder bridge connected at the interior support about actuality bridge have enough structural capacity under service loads.

• Journal of Korean Society of Steel Construction
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• v.18 no.1
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• pp.101-111
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• 2006

The SCP girder, which compensates for the shortcomings of conventional girders through the effective composition of concrete, steel, and PS tendon, has recently been developed and applied on real bridges. Developed as a simple-support type, it may be applied on simple-support and continuous bridges by connecting the simple-support SCP girders to the interior supports. A continuous SCP girder, which has structural and cost advantages over the simple-support SCP girder, is proposed in this study. Likewise proposed herein is a new method of constructing a continuous SCP girder, using segments of the girder sequentially. A two-span, half-scale specimen was designed and constructed to verify the propriety of the continuous SCP girder bridge. A static load test was also carried out, using this specimen, to examine the behavior of the continuous SCP girder. Based on the results of the study, it is expected that the continuous bridge that uses the continuous SCP girder can guarantee the structural safety of the simple-support SCP girder.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.451-452
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• 2010

Prestressed concrete I girder bridge has been one of the most widely used bridges in the world because of its excellent construction feasibility, economic efficiency, serviceability, and safety. But in Korea, the PSC bridge has not been utilized for long span because of high girder height in its standard design. Thus, the results confirm that it is possible to applicate the continuous PSC girder with end cross beam anchorage system using multi-stage prestressing technique.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.4
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• pp.77-83
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• 2014

Prestressed concrete girder bridge has been one of the most widely used bridges in the world because of its excellent construction feasibility, economic efficiency, serviceability, and safety. In certain situations, the prestressing tendon is supposed to be bent by the construction error and the radius of curvature at the continuous joint of PSC girders, and this leads to the loss of prestressing force. However, this kind of prestress loss is not considered in the design and construction processes. This study proves that the prestress loss occurs at the continuous joint due to the local bending of tendon by the construction error or the radius of curvature. Also, a method that can reduce this type of prestress loss is proposed, and proved by the experiment. The result shows that maximum 10% of prestress loss occurs at the continuous joint and the proposed block-out method can reduce the prestress loss ratio by maximum 5%, approximately. This means that the block-out method can enhance the prestressing efficiency of continuous PSC girder bridges.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.3
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• pp.111-119
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• 2022

The increasing sectional stiffness and inducing prestress method of continuous steel box girder using modular CFT members use the restoring force of the CFT module generated from removing the prestressing bars in the CFT module after integrating the prestressed CFT module with the lower steel plate of the steel box girders as a prestressing force. The integrated CFT module in the steel box girder can improve the sectional stiffness of the continuous steel box girder section. To examine the applicability of the introduction of prestressing to the integrated steel box girder using the CFT module, in this study, inducing prestressing tests were conducted using CFT modules for steel plate specimens simulating the lower steel plate of the continuous steel box girder, and FE analyses were conducted for inducing prestressing tests. In addition, to confirm the effect of inducing prestress to the actual steel box girder and increasing sectional stiffness by the CFT modules, FE analyses for the actually applicable continuous steel box section were carried out depending on prestressing force and sectional conditions of the CFT modules, FE analysis results were compared.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.533-536
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• 2008

It is on increasing trend to employ H-rolled beams as main flexural members of bridges and of temporary structures owing to their handiness for construction, maintenance, and management. But in the case of applying H-rolled beams to bridges, maximum length of bridge span is around 20m. Therefore, to develop simplified steel-concrete composite bridge having long span using H-rolled beam needs new cross girder system at internal supports, optimization of bridge system without cross beams between supports and steel-concrete composite bridge deck. This study performs mechanical analysis of cross girder system for H-rolled beam steel-concrete composite bridge with long span and verifies its usefulness.

• Journal of the Korea Concrete Institute
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• v.25 no.5
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• pp.517-528
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• 2013

The modular technology has been already applied in automotive industry, plant and shipbuilding industry. Recently, the modular technology was applied in bridge construction. The modular bridge is different from the existing precast bridges in terms of standardized design that the detailed design of members is omitted by using the standard modules; the design of the modular bridge is completed by only assembling the standard modules without design in member level. The girder-type precast modular bridge has been developed as a simply supported bridge. The girder-type precast modular bridge could be applied to the multi-span bridges through the continuity method. The continuity of the girder-type precast modular bridge is achieved by using the link slab which is easy to construction and appropriate to the rapid construction. The link slabs have been used as the type of reinforced concrete structure in US from the 1950's. In 2000's, the link slab using the engineered cementitious concrete (ECC link slab) has been developed. In this study, the RC type link slab which is more reproducible and economic relative to the ECC link slab was used for the continuity of the girder-type precast modular bridges, and the construction detail of RC type link slab was modified. In addition, the modified iterative design method of RC type link slab was proposed in this study. To verify the proposed design method, the flexural tests were conducted using the RC type link slab specimens. Also, the fatigue test using the mock-up specimen was conducted with cyclic loading condition up to two million cycles.

• Journal of Korean Society of Steel Construction
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• v.18 no.5
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• pp.633-642
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• 2006

Serviceability design is required to control the cracking at the joint of precast decks with longitudinal prestress in continuous composite bridges. Details of twin-girder bridges are especially complex not only due to their main reinforcements and transverse prestresses for the design of long-span concrete slabs, but also due to the shear pockets for obtaining the composite action. This paper suggests the design guidelines for the magnitude of the effective prestress and for the selection of filling materials and their requirements that would allow for the use of precast decks for twin-girder continuous composite bridges. The necessary initial prestress was also evaluated through long-term behavior analysis. From the analysis, existing design examples were revised and their effectiveness was estimated. When a filling material with a bonding strength higher than the requirement is used in the region of a high negative moment, a uniform configuration of the longitudinal prestressing steels along thewhole span length of continuous composite bridges can be achieved, which would result in the simplification of the details and the reduction of the construction costs.

• Journal of the Korea Concrete Institute
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• v.25 no.5
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• pp.555-564
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• 2013

An effective method was proposed in this study which can improve the strengthening effect of continuous girder bridges by external tendons. The improvement of the proposed strengthening method in comparison with conventional methods was analyzed by applying equivalent load concept. In order to verify the strengthening effect, the enhancement of load-carrying capacity achieved by external prestressing was investigated through the test of continuous beams that were or were not strengthened by the external prestressing. The continuous beams were fabricated by making the deck slab continuous according to general construction practice of an actual concrete girder bridge. The test results showed that the deflections and strains of the strengthened beam were significantly reduced when comparing with those of the non-strengthened beam for the same level of external loads, and the stiffness of the member increased by strengthening. In particular, it was verified that the proposed method can effectively reduce the tensile stresses of the deck caused by negative moment at the intermediate supports of a continuous bridge.