• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6A
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• pp.651-659
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• 2009

This study dealt with the behavior of pile-abutment joints in integral abutment bridges. Two types of pile-abutment joints were proposed to strengthen its rigid action. One was fabricated with transverse rebars which penetrated the H-pile in the abutment. The other was composed of stud shear connectors on the flanges of the H-pile. Three half scaled pile-abutment joint specimens were fabricated and loading tests were performed to evaluate the behavior of proposed joints. The results showed that the initial stiffness in elastic region of all specimens was sufficient to be applied for the integral abutment bridges. However, the performances of the proposed joints were shown to be more effective in rigid action compared to the joints types suggested by the Integral Bridge Design Guideline. The results from stiffness, strength, rotation and crack propagation tests supported this matter.

• Journal of Wetlands Research
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• v.22 no.1
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• pp.31-38
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• 2020

Weirs are to secure amount water of streams and drop structures are to enhance stabilization of stream bed and bridges are to connect isolated region, which are called stream crossing structures. In the stream design criteria, directions for minimum size of structures are suggested to secure stability of stream crossing structures. However the sizes of almost all existing weirs and drop structures are not satisfied with the stream design criteria and only 22 percent of the peirs of bridges are satisfied. To enhance hydraulic stability of existing weirs and drop structures, it is required that the ratio of bed protection to apron should be above 3.3. According to factual survey of structures in the sample streams, it has been shown that the longitudinal slope of rapid works with 1:20 is the most reasonable to design velocity if existing weirs and drop structures are rehabilitated into rapid works. It has been known that violating freeboard and span length of piers should make existing bridges reconstructed or removed. However, comprehensive review including deterioration level of bridges, special regulation for span length, etc. should be considered to determine rehabilitation plan of bridges. In this study, a procedure has been suggested to improve hydraulic stability of weirs, drop structures and piers of bridges. Sound environment of stream and reduction of natural disaster could be achieved by improving stability of cross structures, which could be obtained by governmental budget and active stream management including observance of design criteria.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.532-542
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• 2018

Because maglev trains have a propulsion and absorption force without contact with the rails, they can drive safely at high-speed with little oscillation. Recently, test model of a maglev propulsion train was produced and operated, and has since been chosen as a national growth industry in South Korea; there have been many studies and considerable investment in these fields. This study examined the dynamic responses due to bridge-maglev train interaction and basic material to design bridges for maglev trains travelling at high-speed. Depending on the major factors affecting the dynamic effects, the scope of this study was restricted to the relationship between dynamic responses. A concrete box girder was chosen as a bridge model and injured train and rail types in domestic production were selected as the moving train load and guideway analysis model, respectively. From the analysis results, the natural frequency of a bridge for a maglev train, which has a deflection limit L/2000, was higher than those of bridges for general trains. The dynamic responses of the girder of the bridge for a maglev train showed a substantial increase in proportion to the velocities of the moving train like other general bridge cases. Maximum dynamic response of the girder is shown at a moving velocity of 240km/h and increased with increasing moving velocity of train. These results can be used to design a bridge for maglev propulsion trains and provide the basic data to confirm the validity and verification of the design code.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.147-157
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• 2018

The basis of capacity design has been explicitly or implicitly regulated in most bridge design specifications. It is to guarantee ductile failure of entire bridge system by preventing brittle failure of pier members and any other structural members until the columns provides fully enough plastic rotation capacity. Brittle shear is regarded as a mode of failure that should be avoided in reinforced concrete bridge pier design. To provide ductility behavior of column, the one of important factors is that flexural hinge of column must be detailed to ensure adequate and dependable shear strength and deformation capacity. Eight small scale circular reinforced concrete columns were tested under cyclic lateral load with 4.5 aspect ratio. The test variables are longitudinal steel ratio, transverse steel ratio, and axial load ratio. Eight flexurally dominated columns were tested. In all specimens, initial flexural-shear cracks occurred at 1.5% drift ratio. The multiple flexural-shear crack width and length gradually increased until the final stage. The angles of the major inclined cracks measured from the vertical column axis ranged between 42 and 48 degrees. In particular, this study focused on assessing transverse reinforcement contribution to the column shear strength. Transverse reinforcement contribution measured during test. Each three components of transverse reinforcement contribution, axial force contribution and concrete contribution were investigated and compared. It was assessed that the concrete stresses of all specimen were larger than stress limit of Korea Bridge Design Specifications.

• Journal of the Society of Disaster Information
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• v.11 no.3
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• pp.406-412
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• 2015

Recently, frequent earthquakes can cause serious damage to the bridge. So newly constructed bridge is considered earthquake resistant design, and for the existing old bridge evaluation of damage state is needed. In this paper, replacement of US-artificial earthquakes which are used for the construction of fragility curve for evaluating damage state to Korean artificial earthquakes to meet the Korean specifications is studied. For the generation of artificial earthquakes, the fragility curves are constructed for the PGA, for the cases of having isolated bearing and not having that.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2702-2707
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• 2010

The load distribution factor (LDF) values of new composite I-beam panel bridges that were subjected to dead load were investigated using three-dimensional finite element analyses with the computer program ABAQUS(2007). This study considered some design parameters such as the slab thickness, the steel-plate thickness, and the span length for design of new composite bridges. The distribution values that were obtained from these analyses were compared with those from the AASHTO Standard, AASHTO LRFD, and the equations presented by Tarhini and Frederick, and Back and Shin. For the simple application of the design, bridge engineers can use the LDF of 0.67 for the exterior girder and of 0.340 for the interior girder.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.04a
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• pp.42-46
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• 1994

본 연구에서는 프리캐스트 PC 세그멘탈 교량 접합부의 전단거동을 파악하기 위하여 전단키 접합부의 전단거동과 전단강도 특성을 실험적으로 연구하였다. 본 연구를 통하여 접합부 형상에 따른 하중-변위 관계, 균열거동, 파괴모드, 전단강도 등을 규명하고, 접합부의 역학적 거동에 영향을 미치는 여러인자들에 대해 분석한다. 또한 이로부터 최적의 접합부 형상을 도출하고, 이에 따른 최적의 접합방식을 검토함으로써 접합부 설계의 지침과 해석의 근거를 제시한다.

• Magazine of the Korea Concrete Institute
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• v.8 no.3
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• pp.84-92
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• 1996

구조물 붕괴사례에 대한 연구는 항상 공학관련 문헌에 한 부분이 되어 왔으나 교량기술의 향상에 기여할 수 있었던 1840년대와 1930년대 사이에 발생했던 여러 붕괴사례들은 기술혁신이 진행되면서 큰 관심사는 되지 못했던 것 같다. 끊임없이 향상되었던 해석이론 및 구조적 규모면에서 커다란 도약을 성취하였떤 이 시대에도 몇몇 중요한 교량 붕괴사례를 목격하였다. 특히 Tacoma Narrow Bridge의 붕괴가 발생한 후 구조물 붕괴사례에 대한 연구는 구조설계와 시공분야에서 공학적인 통찰력과 판단력을 위한 중요한 자료로 인식되어지게 되었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.723-724
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• 2014

본 연구는 교량시설물의 유지관리에 있어서 사후 대응적 방식에서 예방적 방식으로 전환하기 위해 유지관리와 관련된 이연비용을 관리하는 시스템 도입방안을 제시하고자 하였다. 이를 위해 선행연구사례와 기존 유지관리시스템을 조사하였다. 또한 이연비용관리에 필요한 생애주기 재설계와 데이터 수집 및 관리들의 요건과 이연비용관리시스템을 이용하여 이들 요건을 처리하기 위한 흐름을 구상하였다.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1998.11a
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• pp.309-314
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• 1998

외국의 경우, 지진활동이 활발하지 않은 지역에서 강진이 발생하고, 최근 국내의 빈번해진 지진 발생 등의 이유로 내진설계 기준의 정립 및 강화가 활발히 이루어지고 있다. 그러나 교량의 내진설계는 다음과 같은 몇 가지 한계점을 가지고 있다. l) 첫째 내진구조는 짧은 고유주기로 인하여 유발되는 지진력 자체가 매우 크다. 둘째, 설계지진을 능가하는 지진 발생시 구조물이 붕괴될 가능성이 크다. 즉 내진여유도가 작다. 셋째, 내진설계는 설계지진력 이상의 지진의 발생을 완전히 배제하지 않는데, 그러한 지진발생시 지지력이 모두 고정단이 위치한 교각에 집중되어 그 교각의 받침이 파괴되어 설계개념을 상실할 가능성이 높다. (중략)