• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.477-480
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• 2011

장경간 케이블 교량은 과도한 변위 발생 등의 이유로 엄격한 안전성 및 사용성이 요구되는 철도교량에서는 제한적으로 적용되고 있다. 즉, 철도교량으로서 요구되는 주행안전성과 승차감을 만족하기 위해서는 면밀한 분석이 필요하다. 본 연구에서는 교량/열차 상호작용 해석을 수행하여 열차에서의 응답을 통해 교량 상을 주행하는 열차의 주행안전성 및 승차감을 직접적으로 평가하고자 하였다. 즉, 중앙경간 300m의 현수교를 주행하는 KTX 열차에 대하여 열차 내부의 가속도와 윤중감소율을 구해 평가하는 방법을 취하였다. 또한, 이동 열차하중과 지진하중이 동시에 작용할 경우를 고려한 교량/열차/지진 상호작용해석을 수행하여 지진 시의 응답을 평가하였다.

• 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.

• 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.

• 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.

• 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.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.2
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• pp.169-177
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• 2016

Sliding slab track system, which consists of low friction sliding layer between track slab and bridge deck, is recently devised to reduce track-bridge interaction effect of continuously welded rail(CWR) without applying special devices such as rail expansion joint(REJ). In this study, a series of track-bridge interaction analyses of a long-span bridge with sliding slab track and REJ are performed respectively and the results are compared. The bridge model includes PSC box girder bridge with 9 continuous spans, and steel-concrete composite girder bridge with 2 continuous spans. The total length of the bridge model is 1,205m, and the maximum spacing between the two fixed supports is 825m. Analyses results showed that the sliding slab track system is highly effective on interaction reduction since lower rail additional axial stress is resulted than REJ application. Additionally, horizontal reaction forces in fixed supports were also reduced compared to the results of REJ application. However, higher slab axial forces were developed in the sliding slab track due to the temperature load. Therefore, track slab section of the sliding slab track system should be carefully designed against slab axial forces.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.271-280
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• 2011

This study intends to analytically evaluate the vibration serviceability of the bridges for each long-span type having the same span length and road width using the Meister vibration sensation curve. With MIDAS, a structural analysis program, bridges were modeled using the girders as the frame element and slabs as the plate element. The transient analysis was performed using the moving loads of the design vehicles. This study presents the analytical process of reviewing the vibration serviceability during the design of long-span bridges. It involves the comparison of the vibration serviceability of different bridge types by applying the lagging-behind and acceleration amplitude from transient analysis to Meister curve. The result confirms that the process is appropriate.

• 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.

• Journal of the Korean Society for Railway
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• v.11 no.5
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• pp.471-476
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• 2008

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 types of railway bridge is performed in is study. The suitable girder height and the construction cost 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.32 no.6D
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• pp.579-586
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• 2012

The main objective of the research is to evaluate the laboratory performances of epoxy asphalt mixtures for long-span steel bridge decks. The aggregate gradations were recommended for field applications. The laboratory performance test results showed that the durability of epoxy asphalt mixtures was more noticeable than that of conventional ones. The structural analysis was conducted using resilient modulus and bond-shear test results. The analysis results revealed that just 9% out of total bond-shear stress was enough for the entire required bond-shear stress in the pavement system. The tensile stresses in the bridge decks were within limits compared to the laboratory test results from the Nanjing Grand Bridge in China. As a result, the laboratory performances of the epoxy asphalt mixtures for long-span steel bridge decks were better than those of conventional asphalt mixtures. However, the laboratory performance tests of epoxy asphalt mixtures for long-span steel bridge decks should be conducted precisely since the strengths of the mixtures are sensitive to the temperatures and curing times.