• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.450-453
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• 2011

압출공법(incremental launching method)은 교대 배후에 거더 제작장소를 설치하고, 콘크리트를 이어쳐서 교량거더를 제작하고, 이것을 잭(jack)으로 밀어내는 가설방법이다. 이 공법에 의해 시공되는 교량의 상부단면은 시공 중에 지간의 중앙부와 지점부에 일시적이나마 모두 위치하게 된다. 따라서 단면들은 자중에 의해 발생되는 최대 정모멘트와 최대 부모멘트, 그리고 최대 전단력을 모두 경험하게 되는 구조적 특성을 가지고 있다. 한편 거더의 캔틸레버 작용을 감소시키기 위하여 거더의 선단에 압출추진코(launching nose)를 부착시킨다. 상부단면에 발생하는 이 일시적인 응력의 크기는 압출추진코의 단면특성에 따라 달라진다. 본 논문에서는 압출추진코와 상부단면의 상호작용에 관한 해석식의 정확성을 유지하고, 활용도를 높이기 위해서 압출추진코를 유사등단면(강성;등단면, 중량;변단면)으로 가정하여 단순화된 해석식을 제안하였고, 압출추진코의 단면이 등단면으로 가정한 기존 해석식의 정확성을 향상시키기 위해서 다이아프램의 중량을 집중하중으로 치환시켜 변형된 등단면 해석식을 제안하였다. 그리고 제안된 2개의 해석식의 정확성과 활용성을 판단하기 위해 실제 ILM교량 설계자료들을 통해 전산구조해석 프로그램과, 기존 해석식들과 비교 분석 하였다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.3
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• pp.245-258
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• 2012

ILM(incremental launching method) is a way of construction, installing a girder producing spot behind the abutment, making the bridge girder infilled with concrete continuously and launching with using by jack. The superstructure of the bridge constructed by this method is temporarily located on the center of the span and the supporting points under construction. Therefore, the sections are structurally undergone maximum positive moment, maximum negative moment, and maximum shear force arising from self weight. On the other hand, launching nose is attached to the front of the girder to decrease the cantilever effect. The magnitude of this temporary stress creating on the upper section is dependent upon the launching nose's characteristics. This study has proposed an analysis formula simplified on the assumption that the launching nose section is a quasi-equivalent section(rigid; equivalent section, weight; tapered section) in order to ensure the accuracy of the analysis formula and improve its usage with reference to the interaction between the launching nose and the upper section; and a prismatic analysis formula modified by displacing a diaphragm's weight by a concentrated load in order to improve the accuracy of the existing analysis formula that assumes the launching nose section as the equivalent section. To judge the accuracy and usage of two analysis formulas proposed, we have compared and analyzed computational structural analysis programs and existing analysis formulas based on actual ILM bridge data. As a result, all of two reveal the superior accuracy and also their usage has been improved by the simplification of analysis formulas.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.2
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• pp.318-328
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• 1991

The present paper describes the experimental study on the fixed-type wave-energy conversion system, consisting of the OWC-type wave-energy absorbing chamber and the duct for the air turbine. For simplicity, a screen of wire mesh was employed in place of an air turbine in order to simulate its effects on OWC chamber. Experiments were performed at the towing tank in regular waves with the frequency range of 0.22-0.75Hz. Comparison wish the numerical prediction using a potential flow-based method [4] was made to validate the capability of numerical code. It was shown that the agreements between measured and calculated results are quite good, giving a confidence in prediction method. Simulation of air turbine using a wire-mesh screen was successful, at least in a qualitative sense, to investigate the inter action between the OWC chamber and an air turbine. Results also showed that the effects of a wire-mesh screen on chamber efficiency are negligible, and the present model can be effectively utilized for the practical use in ocean waves with the frequency range under 0.3Hz.

• Journal of the Korea Concrete Institute
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• v.22 no.6
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• pp.797-803
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• 2010

A dynamic analysis procedure is developed to provide a better estimation of the dynamic responses of pre-stressed concrete (PSC) box girder bridges on the Korea high speed railway. Particularly, a three dimensional numerical model including the structural interaction between high speed vehicles, bridges and railway endures to analyze accurately and evaluate with in-depth parametric studies for dynamic responses of bridge due to the high speed railway vehicles. Three dimensional frame element is used to model the PSC box girder bridges, simply supported span lengths 40 m. The high-speed railway vehicles (K-TGV) including a locomotive are used as 38-degree of freedom system. Three displacements (vertical, lateral, and longitudinal) as well as three rotational components (pitching, rolling, and yawing) are considered in the 38-degree of freedom model. The dynamic analysis by Runge-Kutta method which are able to analyze considering the dynamic impact factors are compared and contrasted. It is proposed as an empirical formula that the impact factors damaged the bridge load-carrying capacities occurs to the bride due to high-speed vehicle.