• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3A
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• pp.243-250
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• 2009

The purpose of this study is to investigate several strategies that can be used to extend the span of conventional PSC girder bridge and to propose a systematic procedure to evaluate the effect of each strategy on the span. In the preceding companion paper, fundamental equations were derived which constitute the assessment graphs and a possible domain for the design. Quantitative evaluation for extension of the span follows here by adopting a sample PSC girder bridge. It apparently shows a number of advantages of the proposed scheme in finding out why and how each strategy contributes to the span extension and in suggesting further improvement for a longer span. The results imply that increasing the strength of a girder, the multistage prestressing with the secondary tendons prestressed before composite action with a deck, and Decked PSC girder are very effective among the strategies examined. It is expected that the span of the PSC girder bridge can be well extended up to 50 m to 70 m which corresponds to a span of the conventional box girder bridges.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3A
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• pp.235-241
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• 2009

PSC girder bridge is known to be more economical than other types of bridges and has been usually applied to a span range of 25 m to 35 m according to the standard shapes for highway bridges in Korea. The spans of the recently developed new types of PSC girders are also limited to 50 m at most. In this study, therefore, feasibility of the long-span PSC girder that reaches more than 50 m is investigated by applying several strategies from the perspectives of materials, design and construction. A systematic procedure is proposed that can be used to assess the effect of each strategy on the span. The proposed scheme adopts a graphical approach that represents a relationship between the number of prestressing tendons and the span, and is derived on a basis of safety assessment equations of the girder in each stage of fabrication and in service. In the companion paper, the amount of span extension is quantitatively evaluated by applying the proposed scheme into a sample PSC girder bridge.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.234-237
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• 2010

본 연구에서는 변단면을 갖는 FCM(Free Cantilever Method) 교량의 설계 단계에서 교각 위치 변경에 따른 경간장 변화와 그로 인한 박스 거더의 형상을 자동 조정하여 설계단계에서의 효율성 향상을 위해 3차원 파라메트릭 모델링 방법을 적용하였다. 이를 위해 FCM 교량 설계 지침서를 분석하여 경간장 변화와 관련된 매개변수들을 추출하고 이들의 관계를 구속조건으로 정의하였다. 또한, 정의한 구속조건의 적용을 통해 대상교량의 파라메트릭 모델링을 수행하여 그 적용 가능성을 검증했으며 결과로 생성된 교량 모델의 물량산출을 수행하여 모델의 정확성을 검증했다.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2224-2225
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• 2008

가공배전선로는 야외에 시설됨에 따라 태풍과 같은 자연재해로 인한 전기고장 및 설비피해가 발생하기 쉽다. 그러나 이와 관련한 연구들이 이론적인 부분에만 치우쳐 장경간 가공배전선로의 설계 시 어떤 순서로 무엇을 검토해야하는지 알기가 어려웠다. 따라서 본 고에서는 장경간 가공배전선로 설계시 전선종류, 장주형태, 완철간 수직이격거리 및 지지물 길이를 결정하는 방법에 대하여 연구한 결과를 사례를 통해 설명하였다. 본 고에서 제시한 방법에 따라 설계를 시행한다면 장경간 가공배전선의 선간단락고장을 예방할 수 있을 뿐만 아니라, 홍수 시에도 수면으로부터 충분한 지상고 유지를 위하 고장 및 설비피해를 예방할 수 있을 것으로 기대된다.

• Railway Journal
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• v.15 no.3
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• pp.27-31
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• 2012

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.23-24
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• 2010

In this research, the comparison and analysis of domestic prestressed concrete bridges were performed with major variations of superstructure type, and span lengths using the 'current status of roadbridge and tunnel' informations provided by MLTM and STATISTICS KOREA. As a result of analysis, steel box girder bridges with 50~100m span length represent about 76% of bridges, but prestressed concrete bridges represent a relatively smaller percentage. In order to replace steel box girder bridges with prestressed concrete bridges, it is necessary to develop prestressed concrete bridges with high-strength tendons and concrete.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2226-2227
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• 2008

가공배전선로는 태풍과 같은 자연재해에 상시 노출되어 시설되므로 전기고장 및 설비피해가 발생할 우려가 매우 높다. 그러나 이와 관련한 실질적인 연구들이 부족하여 가공배전선로의 설계원들이 직선선로의 경간 결정시 단순히 저압부하밀도 및 전주강도만을 고려하고 있으며, 인류지선 및 종지선의 규격 선정방법을 잘 이해하지 못함에 따라 규격 선정의 오류가 발생되기도 한다. 따라서 본 고에서는 그 동안의 연구결과를 바탕으로 가공배전선로 설계시 수평선간이격거리를 고려한 경간 결정방법과 장경간 및 표준경간의 인류지선, 장경간개소 종지선 결정방법에 대하여 사례를 통해서 설명하였다. 본 고에서 제시한 방법에 따라 설계검토를 시행한다면 표준경간에서 선간단락고장을 예방할 수 있을 뿐만 아니라, 장경간 및 표준경간의 인류지선 및 종지선의 강도가 재해시에도 충분한 강도를 확보하여 설비피해 및 전기고장을 예방할 수 있을 것으로 기대된다.

• The Journal of the Korea Contents Association
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• v.14 no.7
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• pp.511-517
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• 2014

The superstructure type of the railway bridge in our country, is mainly classified into the box girder and the I-type girder. The box girder is widely used in the high speed railway bridge because of the safety due to dynamic behavior. The I-type girder is used in the conventional railway bridge, and is also divided into the general type and the composite type, and the newly modified types have been developed. According to the current railway bridge design code, the girder design by the span length in various railway bridge types are performed in this study. The suitable girder height by the span length are analyzed, and the comparative analysis of the structural efficiency and the economical efficiency is carried out. From this study, the composite type girder is appeared the good result in respect of the structural efficiency. However, in the economical aspect, the general I-type girder is required less cost than the other types.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2A
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• pp.93-102
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• 2010

The numerical analysis and safety assessment by construction stages were considered the essential examination particular in order to solving the unstability of long-span bridges in the middle a construction. When estimating structural response characteristics by the construction stage analysis of long-span bridges, the influence of the near-field ground motion (NFGM) would be evaluated as a critical factor for the seismic design because it indicates clearly different aspects from the existing input earthquake motion data. Therefore, this study re-examined the response aspect of long-span bridges considering NFGM characteristics based on the response spectrum result, and advanced the presented numerical analysis program by the related research for conducting the construction stage analysis and reliability assessment of long-span bridges efficiently. The excellency of various construction schemes was assessed using the time history analysis result of critical member considering NFGM characteristics. For evaluating quantitative safety level, the reliability analysis was conducted considering the influence of external uncertainties included in random variables, and presented the safety index and failure probability of the critical construction stage by NFGM characteristics. In addition, the reliability result was examined the influence of internal uncertainties using monte carlo simulation (MCS), and assessed the distribution aspect of the essential analysis result. It is expected that this study will provide the basic information for the construction safety improvement when performing seismic design of long-span bridges considering NFGM characteristics.

• Railway Journal
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• v.15 no.6
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• pp.48-52
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• 2012