• Structural Engineering and Mechanics
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• 제42권1호
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• pp.55-72
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• 2012

Precast-cast insitu concrete bridge construction is widely practiced for small to medium span structures. These bridges consist of precast pre-stressed concrete beams of various cross-sections with a cast in-situ reinforced concrete slab. The connection between the beams and the slab is via shear links often included during the manufacturing process of the beams. This form of construction is attractive as it provides for standardisation, reduced formwork and construction time. The assessment of the integrity of shear connectors in existing bridges is a major challenge. A procedure for assessment of shear connectors based on vibration testing and finite element model updating is proposed. The technique is applied successfully to a scaled model bridge model and an existing bridge structure.

• 콘크리트학회논문집
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• 제20권6호
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• pp.833-840
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• 2008

부분 프리캐스트 콘크리트 부재를 계단실에 적용할 때 현장타설이나 PC공법에 비해 시간 및 비용을 절감할 수 있다. 부분 프리캐스트 계단 부재는 각 부재의 접합방식에 따라 피난용도로 사용되는 계단실의 성능이 매우 달라질 수 있으므로 계단 접합부의 종류에 따른 성능평가를 실험적 연구를 통해 알아보고자 하였다. 현장타설되는 일체형 접합부는 계단참 끝단에 응력이 집중되어 많은 보강이 필요하고, PC공법에서 사용되는 핀접합부는 경사계단의 중앙부에 최대응력이 발생되며, 접합부의 휨성능을 무시하기 때문에 철근 배근량이 증가할 뿐만 아니라 사용성이 현저히 떨어지게 된다. 이러한 단점을 보완한 볼트형 반강접 접합부는 일체형에 가까운 내력을 보유하였으며, 연성비는 일체형에 비해 약 0.7배, 핀접합형에 비해 약 2.8배의 성능을 가져 지진하중 등의 횡하중에 대한 성능도 뛰어남을 알 수 있었다. Eurocode 접합부 분류기준에서는 semi rigid-full strength에 속하는 반강접합으로 볼 수 있고, 강성감소율 40%를 적용한 모델을 이용하여 거동을 예측할 수 있다.

• International Journal of Concrete Structures and Materials
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• 제9권1호
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• pp.45-54
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• 2015

This paper describes a three-dimensional approach to modeling the nonlinear behavior of partial-depth precast prestressed concrete bridge decks under increasing static loading. Six full-size panels were analyzed with this approach where the damage plasticity constitutive model was used to model concrete. Numerical results were compared and validated with the experimental data and showed reasonable agreement. The discrepancy between numerical and experimental values of load capacities was within six while the discrepancy of mid-span displacement was within 10 %. Parametric study was also conducted to show that higher accuracy could be achieved with lower values of the viscosity parameter but with an increase in the calculation effort.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.307-310
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• 2005

The PCS system, which consists of precast concrete column and steel beam, has been under development. Experimental test has been carried out to investigate the structural performance of the system under earthquake. Two types of test specimens of beam-column joints are designed in order to compare the performances. One is the system with reinforced concrete slab and the other is without slab. It is found that the system with slab could satisfy all of the requirements from ACI Criteria such as strength, stiffness degradation and energy dissipation capacity except initial stiffness. It is also investigated that the stiffness of the joint is belong to rigid joint type according to Bjorhovde criterion. And it is observed that the partial-composite system between beam and slab is more effective than full-composite system in the respect of the energy dissipation capacity of the system.

• Earthquakes and Structures
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• 제26권6호
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• pp.449-461
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• 2024

The vertical reinforcement connection between the precast reinforced concrete shear wall and the cast-in-place reinforced concrete member is vital to the performance of shear walls under seismic loading. This paper investigated the structural behavior of three precast reinforced concrete shear walls, with different levels of connection (i.e., full connection, partial connection, and no connection), subjected to quasi-static lateral loading. The specimens were subjected to a constant vertical load, resulting in an axial load ratio of 0.4. The crack pattern, failure modes, load-displacement relationships, ductility, and energy dissipation characteristics are presented and discussed. The resultant seismic performances of the three tested specimens were compared in terms of skeleton curve, load-bearing capacity, stiffness, ductility, energy dissipation capacity, and viscous damping. The seismic performance of the partially connected shear wall was found to be comparable to that of the fully connected shear wall, exhibiting 1.7% and 3.5% higher yield and peak load capacities, 9.2% higher deformability, and similar variation in stiffness, energy dissipation capacity and viscous damping at increasing load levels. In comparison, the seismic performance of the non-connected shear wall was inferior, exhibiting 12.8% and 16.4% lower loads at the yield and peak load stages, 3.6% lower deformability, and significantly lower energy dissipation capacity at lower displacement and lower viscous damping.

• 콘크리트학회논문집
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• 제12권6호
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• pp.43-50
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• 2000

In this paper, a new splicing method was applied to design the girder section of bridges with the span length of 25m, 30m, 35m, 40m and 45m. A U-type precast prestressed section was also determined for each bridge. Additionally, the sectional area, beam depth and Guyon's efficiency factor of the spliced U-type sections in each span were analyzed in comparison with the present I-type PSC bridges. As a result, in spite of an increase of 31%∼50% in the sectional areas compared with the I-type precast girders, the spliced U-type the beam depth of the spliced U-type girder was designed as 2,050 mm compared with the I-type precast girder of 2,600mm in a 40m span bridge. The sectional efficiency factors of the spliced U-type sections were analyzed as 0.76∼0.99. It shows that the spliced U-type sections ar of a superior structural efficiency in contrast to the average sectional efficiency factor of 0.66 value in the I-type girders.

• 한국강구조학회 논문집
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• 제10권4호통권37호
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• pp.759-767
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• 1998

프리캐스트 콘크리트 바닥판을 갖는 교량은 각각의 프리캐스트 바닥판에 전단연결재를 위한 흠을 두어서 강주형과 합성시키는 시스템을 갖는다. 전단연결재를 위한 홈을 무수축모르터로 채울 경우의 전단연결재 설계에 필요한 전단연결부의 강도와 강성의 산정식에 대한 해석적 검토를 수행한다. 허용응력 설계법을 프리캐스트 콘크리트 교량 바닥판에 적용할 경우에 대해 전단연결재의 배치방법을 단순교에 대해 신설과 보수의 경우로 나누어 교량 시스템에 적합하도록 제시하고 지점부 프리캐스트 바닥판의 상세를 제안한다. 강도설계 및 피로설계에 의한 설계방법을 적용할 경우에 대해서 부분합성 이론을 이용한 변수연구를 통해서 프리캐스트 콘크리트 바닥판 교량에 적합한 전단연결재의 배치방법을 제안한다. 실험 및 해석적 연구결과로부터 무수축모르터의 강도 영향을 제시하고 실제 적용시 적절한 강도기준을 제시한다.

• Steel and Composite Structures
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• 제37권5호
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• pp.605-620
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• 2020

An innovative Partially Precast Steel Reinforced Concrete (PPSRC) beam is presented in this paper. To study the shear behavior of PPSRC beams, static loading experiments were conducted on 10 specimens, including 4 T-beam specimens and 4 PPSRC inverted T-beam specimens together with 2 PPSRC rectangular section beams. In the tests, the shear behaviors of the PPSRC beams were emphasized. On the basis of the experiments, the failure mode and ultimate bearing capacity were thoroughly examined. The calculation methods for shear capacity are also presented in this paper. The analysis of mechanical behavior and the calculation methods presented can be used as a reference to design these innovative composite PPSRC beams and provide a significant foundation for further research.

• 한국안전학회지
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• 제21권3호
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• pp.94-100
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• 2006

The goal of this study is to show the way to increase the safety of deteriorated PSC beam bridges by the to-box reinforcing method. This method is to change the open girder section into the closed box section by connecting bottom flanges of neighboring PSC girders with the precast panels embedding PS tendons at the anchor block. The box section is composed of three concrete members with different casting ages, RC slab, PSC beam, precast panel. This different aging requires a time-dependent analysis considering construction sequences. Reliability index and failure probability are produced by the AFOSM reliability analysis. Transversely five schemes and longitudinally two schemes are considered. The full reinforcing scheme, transversely and longitudinally, shows the highest reliability index, but it requires more cost for retrofit. The partial reinforcing scheme 4, 4-1 are recommended in this study as the economically best scheme.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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• pp.193-200
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• 1998

The precast prestressed concrete girders of I-type section are frequently employed to design the short-to-medium span bridge. However, its beam depth is greatly increased as its span length is increased over than about 30m. Therefore, the economic and aesthetic effectiveness are rapidly decreased in case of the span length over 30m. The purpose of this paper is to verify the structural safety on the new spliced two span bridge and analyze the variation of member forces and stress distribution according to the construction stages and time. The new spliced technique is performed by partial post tensioning and release in the U-type girders. The structural characteristics of this technique is the introduction of secondary moment to reduce the bending moment by self weight of precast U-type girders constructed in simply supported beam type. So, it is expected that the structural efficiency of this spliced bridge may be improved more than other techniques.