• Computational Structural Engineering
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• v.14 no.3
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• pp.65-69
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• 2001

• 레미콘
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• no.4 s.59
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• pp.16-23
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• 1999

• 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.

• 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.

• Computational Structural Engineering
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• v.13 no.4
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• pp.15-18
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• 2000

• Computational Structural Engineering
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• v.13 no.2
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• pp.36-42
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• 2000

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.4
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• pp.225-232
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• 2002

Recently the slab span-jointing method has been employed as one of the retrofit technologies to enhance the capacity of existing simple beam bridges in many cases. In general this method makes simple beam bridges behave like multi-span continuous bridges under service loads excluding self weight in company with external prestress force method in the field. In this paper the continuation effect has been studied for the retrofitted bridges by the experimental and numerical approaches. The results show that the deflections and stresses of members are reduced due to the increase of the total stiffness of bridge system and the efficiency of bridge continuation based on the slab span-jointing method is about 40 % when comparing with the case of continuous bridges.

• Journal of Korean Society of Steel Construction
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• v.13 no.4
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• pp.433-441
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• 2001

Thus study presents the basic concepts of 3 span continuous preflex composite beam of bridges by re-up down of supports and analysis relationship of between variables and stress of critical section. Also, it shows the pre-compression effects of re-up down of supports method by presenting the difference of between old section and new section got from new method. This study's new method makes more economic sections to be possible and when the sections designed with the existing method are used in the new method. efficient stress state is accomplished.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1995.06a
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• pp.35-46
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• 1995

TR 단조공법은 기존의 프레스에 특수장치를 장착하여 프레스의 수직힘과 수평함을 동시에 갖도록 하여 일체형의 크랭크샤프트를 제작하는 공법으로, 연속입자흐름의 크랭크쓰 로우를 제작할 수 있기 때문에 보다 우수한 특성의 크랭크샤프트를 제작할 수 있다. TR 단 조공법을 이용한 크랭크샤프트의 제작은 하나의 소재로 단조하여 제작하기 때문에 기존과는 다른 작업공법 및 전용장비가 필요하나 국내에서는 이러한 공법이나 설비의 부재로 인해 생 산되지 못한 제품이었다. 본 개발에서는 중형엔진용 크랭크샤프트의 국산화를 실현한 측면 에서 TR 단조공법 및 장치에 대한 소개와 본 단조공법을 적용하여 제작된 크랭크샤프트의 제반 특성평가를 수행하여 균일한 물성 및 연속입자흐름에 따른 피로강도의 향상 여부를 확 인하였다.

• 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.