• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.553-558
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• 2001

Recent destructive seismic events demonstrated the importance of mitigating human casualties and serious property damages in design and construction of structures. The Korean Bridge Design Specifications (1992) adopted seismic design requirements based on the AASHTO specification, and minor modification was made in 2000. The longitudinal steel connection of reinforced concrete bridge column is sometimes practically unavoidable. The longitudinal reinforcement details affect seismic performance such as flexural failure and shear failure. This research aims to develop longitudinal steel connection details with confinement steel by experimental study for seismic performance of reinforced concrete bridge columns. Quasi-static test under three different axial load levels was conducted for 12 spiral column specimens. All the column specimens had the same aspect ratio of 3.5. The column specimens were transversely reinforced with spiral and with five different longitudinal steel connection. The final objective of this study is to suggest appropriate longitudinal reinforcement connection details for the limited ductility design concept and improve construction quality.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2001년도 춘계학술대회 논문집
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• pp.345-352
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• 2001

Recent destructive seismic events demonstrated the importance of mitigating human casualties and serious property damages in design and construction of structures. The Korean Bridge Design Specifications (1992) adopted seismic design requirements based on the AASHTO specification, and minor modification was made in 2000. The longitudinal steel connection of reinforced concrete bridge column is sometimes practically unavoidable. The longitudinal reinforcement details affect seisimc performance such as flexural failure and shear failure. This research aims to develop longitudinal steel connection details with confinement steel by experimental study for seismic performance of reinforced concrete bridge columns. Quasi-static test under three different axial load levels was conducted for 12 spiral column specimens. All the column specimens had the same aspect ratio of 3.5. The column specimens were transversely reinforced with spiral and with five different longitudinal steel connection. The final objective of this study is to suggest appropriate longitudinal reinforcement connection details for the limited ductility design concept and improve construction quality.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.647-654
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• 2006

In orthotropic steel decks, it is likely to have defects due to fatigue damages because most of structural joints(the connection of longitudinal rib and transverse rib, the connection of deck plate and longitudinal rib) are connected by welds. However. orthotropic steel decks have many advantages. such as light weight and reduction of construction time. in comparison with concrete decks. Therefore. they are mostly used in long-span bridges and urban highway bridges. This study consists of the cause identication of fatigue damage and the suggestion of rational thickness on deck plate about the connection of deck plate and longitudinal rib. The results are as follows: fatigue damage cause at the connection of deck plate and longitudinal rib is local deformation in deck plate. And, rational thickness of deck plate is 16mm thickness.

• 콘크리트학회논문집
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• 제16권1호
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• pp.111-124
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• 2004

축방향철근의 연결상세에 따라 7개 그룹 총 21개의 원형나선철근 기둥 시험체를 제작하여 준정적 실험을 수행하였다. 축방향철근 연결상세(단일철근, 겹침이음 및 기계적연결), 심부구속철근비, 축력비 등을 주요 실험변수로 채택하였으며 실험결과 축방향철근 연결상세에 따라 다른 파괴거동을 나타내었고, 내진성능에서도 차이를 나타내었다. 축방향철근이 겹침이음된 시험체의 실험결과, 모든 축방향철근이 겹침이음된 시험체는 내진성능이 상당히 저하되는 것으로 나타났으나, 축방향철근의 $50\%$가 겹침이음된 시험체의 경우 제한적이지만 한정적인 연성능력을 나타내었다. 또한, 축방향철근을 커플러를 사용하여 기계적으로 연결한 시험체는 축방향철근이 단일철근으로 구성된 시험체와 유사한 파괴거동 및 강도저감거동을 나타내었다.

• 콘크리트학회논문집
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• 제16권2호
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• pp.249-260
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• 2004

철근콘크리트 교각의 소성힌지 구간에서의 축방향철근의 겹침이음은 내진성능면에서 바람직하지 않으나, 축방향철근의 겹침이음을 피하는 철근상세가 현실적으로 어려운 실정이며 현행 도로교설계기준에는 축방향철근 겹침이음 금지에 관한 특별한 설계기준이 없는 상태이다. 본 연구는 반복하중을 받는 철근콘크리트 원형교각의 축방향철근 연결상세에 따른 내진성능을 평가하기 위해 축방향철근 연결상세에 따른 7개 그룹 총 21개의 원형나선철근 기둥 시험체에 대한 준정적실험을 수행하였다. 실험결과 축방향철근이 겹침이음 되어있는 시험체의 경우, 단일 축방향철근으로 구성된 시험체보다 낮은 내진성능을 나타내었으며 특히, 모든 축방향철근이 겹침이음 되어있는 경우 내진성능이 상당히 저하되었다. 그러나, 축방향철근을 기계적 연결장치로 연결한 시험체의 경우 단일축방향철근 상세를 가지는 시험체와 유사한 내진성능을 나타내었다. 본 연구의 최종목적은 철근콘크리트 교각의 시공성 향상을 위한 축방향철근 연결상세의 제시 및 한정연성 내진설계를 위한 실험적 기초자료의 제공과 함께 성능단계별 축방향철근 연결상세에 따른 성능 및 손상평가를 위한 정량적 수치와 경향을 제공하기 위한 것이며, 극한변위, 극한드리프트비율, 변위연성도, 응답수정계수, 등가점성감쇠비, 잔류변형지수, 유효강성 등의 주요 내진성능평가 변수들에 대한 분석결과를 나타내었다.

• Steel and Composite Structures
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• 제23권3호
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• pp.351-362
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• 2017

This paper presents an experimental study on the behavior of composite floor slab comprised by a new steel sheet and concrete slab. The strength of composite slabs depends mainly on the strength of the connection between the steel sheet and concrete, which is denoted by longitudinal shear strength. The composite slabs have three main failures modes, failure by bending, vertical shear failure and longitudinal shear failure. These modes are based on the load versus deflection curves that are obtained in bending tests. The longitudinal shear failure is brittle due to the mechanical connection was not capable of transferring the shear force until the failure by bending occurs. The vertical shear failure is observed in slabs with short span, large heights and high concentrated loads subjected near the supports. In order to analyze the behavior of the composite slab with a new steel sheet, six bending tests were undertaken aiming to provide information on their longitudinal shear strength, and to assess the failure mechanisms of the proposed connections. Two groups of slabs were tested, one with 3000 mm in length and other with 1500 mm in length. The tested composite slabs showed satisfactory composite behavior and longitudinal shear resistance, as good as well, the analysis confirmed that the developed sheet is suitable for use in composite structures without damage to the global behavior.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.1084-1089
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• 2004

Recently, Orthotropic steel deck bridges, which have long span decks, have been regarded as one of economical as well as durable bridge types. However, Orthotropic steel deck bridge is used by a lot of welding, which may cause welding defect and deformation of connections. This kind of system happens some damages by the fatigue cracks of welding. The cross-connection of longitudinal rib and transversal rib is one of the weakest point because of the fatigue. The secondary stresses which are from the out-plane deformation of transversal rib and the torsion of longitudinal rib make the topical stress concentration phenomenon. But, it is principle that a Bulkhead Plate is not established in the domestic design standard. Therefore, it is estimated that a study for the installing of Bulkhead Plate is needed. This study with considering these circumstances proves efficiency of Bulkhead Plate and will be presented optimal design details through finite element analysis according to change the geometrical system of Bulkhead Plate and the cross-connection area of longitudinal and transversal rib

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2004년도 봄 학술발표회 논문집
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• pp.177-184
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• 2004

Orthotropic steel deck bridge has much advantages such as the light deadweight, so the construction of orthotropic steel deck is profitable for the long-span bridges Although the system has a lot of merits, it happens some damages by the traffic density and the fatigue cracks of welding. The cross-connection of longitudinal rib and transversal rib is one of the weakest at the fatigue. The secondary stresses which are from the out-plane deformation of transversal rib and the torsion of longitudinal rib make the topical stress concentration phenomenon. The Bulkhead Plate for prevention of this stress concentration phenomenon was applied by changing the orthotropic steel deck of Williamsburg bridge in USA. But, it is principle that a Bulkhead Plate is not established in the domestic design standard. Therefore, it is estimated that the study for installation of Bulkhead Plate is needed. This study with considering these circumstances proves efficiency of Bulkhead Plate and will be presented optimal design details through finite element analysis according to change the geometrical of Bulkhead Plate and the cross-connection area of longitudinal and transversal rib

• Structural Engineering and Mechanics
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• 제34권5호
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• pp.563-580
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• 2010

Composite beams using bolts to attach steel plates to the side faces of existing reinforced concrete (RC) coupling beams can enhance both their strength and deformability. The behavior of those composite beams differs substantially from the behavior of typical composite beams made up of steel beams and concrete slabs. The former are subjected to longitudinal, vertical and rotational slips, while the latter only involve longitudinal slip. In this study, a mixed analysis method was adopted to develop the fundamental equations for accurate prediction of the load-carrying capacity of steel plate strengthened RC coupling beams. Then, a rigid plastic analysis technique was used to cope with the full composite effect of the bolt group connections. Two theoretical models for the determination of the strength of medium-length plate strengthened coupling beams based on mixed analysis and rigid plastic methods are presented. The strength of the strengthened coupling beams is derived. The vertical and longitudinal slips of the steel plates and the shear strength of the anchor-bolt connection group is considered. The theoretical models are validated by the available experimental results presented in a companion paper. The strength of the specimens predicted from the mixed analysis model is found to be in good agreement with that from the experimental results.

• Steel and Composite Structures
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• 제17권5호
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• pp.573-599
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• 2014

A new type of connection for steel-concrete composite bridges was developed by the Steel Structures Laboratory of Ecole Poytechinque $F{\acute{e}}d{\acute{e}}rale$ de Lausanne. Resistance to longitudinal shear is based on the development of shear stresses in the confined interfaces which form the connection. Confinement is provided by the reinforced concrete slab which encloses the connection and restrains the uplift (lateral separation) of the interfaces by developing normal stresses. The experimental investigation of the interfaces, under static and cyclic loading, enabled the development of the laws describing the structural behaviour of each interface. Those laws were presented by the authors in previous papers. The current paper focuses on the continuity of the research. It presents the experimental investigation on the new connection by means of push-out tests on specimens submitted to static and cyclic shear loading. Investigation revealed that the damage in the connection, due to cyclic loading, is expressed by the accumulation of a residual slip. A safe fatigue failure criterion is proposed for the connection which enabled the verification of the connection for the fatigue limit state with respect to the limit of fatigue. A numerical model is developed which takes into account the laws describing the interface behaviour and the analytical expressions for the confinement effect, the latter obtained by performing finite element analysis. This numerical model predicts the shear resistance of the connection and enables to assess its fatigue limit which is necessary for the fatigue design proposed.