• 대한토목학회논문집
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• 제34권6호
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• pp.1667-1676
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• 2014

강합성 바닥판은 두 방향의 휨 강성이 다르기 때문에 직교이방성의 성질을 가진다. 강합성 바닥판의 휨 강성비는 활하중 모멘트에 영향을 미친다. 비충전 강합성 바닥판의 휨 강성비는 메인 베아링 바 간격과 직접적인 관계를 가지고 있어 메인 베아링 바 간격과 형상비 영향이 고려된 하중분배 계수식에 대한 연구가 필요한 것으로 판단된다. 본 연구에서는 휨 강성비를 고려하는 AASHTO LRFD Bridge Design Specification에 의한 비충전 강합성 바닥판의 활하중 모멘트를 평가하고 비충전 강합성 바닥판의 하중분배 계수식을 제안하고자 한다.

• Earthquakes and Structures
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• 제16권2호
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• pp.185-196
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• 2019

One of the shortcomings of seismic bridge design codes is the lack of clarity in defining the role of different seismic isolation systems with linear or nonlinear behavior in terms of R-factor. For example, based on AASHTO guide specifications for seismic isolation design, R-factor for all substructure elements of isolated bridges should be half of those expressed in the AASHTO standard specifications for highway bridges (i.e., R=3 for single columns and R=5 for multiple column bent) but not less than 1.50. However, no distinction is made between two commonly used types of seismic isolation devices, i.e., elastomeric rubber bearing (ERB) with linear behavior, and lead rubber bearing (LRB) with nonlinear behavior. In this paper, five existing bridges located in Iran with two types of deck-pier connection including ERB and LRB isolators, and two bridge models with monolithic deck-pier connection are developed and their R-factor values are assessed based on the Uang's method. The average R-factors for the bridges with ERB isolators are calculated as 3.89 and 4.91 in the longitudinal and transverse directions, respectively, which are not in consonance with the AASHTO guide specifications for seismic isolation design (i.e., R=3/2=1.5 for the longitudinal direction and R=5/2=2.5 for the transverse direction). This is a clear indicator that the code-prescribed R-factors are conservative for typical bridges with ERB isolators. Also for the bridges with LRB isolators, the average computed R-factors equal 1.652 and 2.232 in the longitudinal and transverse directions, respectively, which are in a good agreement with the code-specified R-factor values. Moreover, in the bridges with monolithic deck-pier connection, the average R-factor in the longitudinal direction is obtained as 2.92 which is close to the specified R-factor in the bridge design codes (i.e., 3), and in the transverse direction is obtained as 2.41 which is about half of the corresponding R-factor value in the specifications (i.e., 5).

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.518-523
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• 2003

In domestic composite bridges, it has been reported that most failure is occurred in deck and the type of failure was mainly punching shear failure. Therefore to increase a life of bridges and reduce maintenance costs, an improvement of a durability of slabs is needed. In these respects, precast deck can be very useful. In a composite bridge with precast decks, it is required to notice behavior of transverse joints between decks. In this paper, bending tests of precast deck with loop joints were conducted. From the results, the validity of loop joints for continuity of deck was observed and especially an interval of loop joint, diameter of loop and reinforcement were checked.

• Journal of Welding and Joining
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• 제28권5호
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• pp.64-68
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• 2010

The purpose of this study is to develop the control technology of global distortion in the deck of superstructures during manufacturing processes. The behavior of global distortion in the deck was evaluated by FEA and verified through comparing with the measured results by 3D measuring instrument. It was seen from the results that the principal factor inducing the global distortion is to be the bending moment associated with the longitudinal shrinkage force and transverse shrinkage caused by welding of stiffeners and flame heating to correct the excessive local out-of-plane distortion. Based on the results, the amount of reverse distortion in the thin deck plate was determined to control the global distortion in the deck plate. The proposed distortion control technology was verified by applying it to the actual structure.

• 한국안전학회지
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• 제30권6호
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• pp.70-77
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• 2015

In this study, the governing design factors of GFRP-reinforced concrete bridge deck are analyzed for typical bridges in Korea. The adopted bridge deck is a cast-in-situ concrete bridge deck for the prestressed concrete girder bridge with dimensions of 240 mm thickness and 2.75 m span length from center-to-center of supporting girders. The selected design variables are the diameters of GFRP rebar, spacings of GFRP rebars and concrete cover thicknesses, Considering the absence of the specification relating GFRP rebar in Korea, AASHTO specification is used to design the GFRP-reinforced concrete bridge deck. The GFRP-reinforced concrete bridge deck is proved to be governed by the criteria about serviceability, especially maximum crack width, while steel reinforced concrete bridge deck is governed by the criteria on ultimate limit state. In addition, GFRP rebars with diameter of 16 mm ~ 19 mm should be used for the main transverse direction of decks to assure appropriate rebar spacings.

• Journal of the Korean Wood Science and Technology
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• 제40권6호
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• pp.397-405
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• 2012

최근 국내에서 목질계 재료를 이용한 데크의 설치사례는 증가하는 추세이나, 상대적으로 데크의 기초 물성과 안전성에 관련된 연구는 미흡한 상황이다. 신발과 데크 사이에서 발생하는 마찰력은 보행자의 기동 능력에 많은 영향을 미친다. 이러한 마찰력은 바닥재의 재료 특성, 바닥재의 요철무늬 형상, 신발 밑창의 형태, 바닥재와 신발 사이 접촉면의 습윤도 등 여러 인자에 의해 영향을 받는다. 본 연구에서는 보행안전성 평가를 위하여 데크의 요철무늬에 따른 마찰력 변화를 측정하고 미끄럼 정도를 평가하였다. 실험에 이용된 데크의 재료는 천연목재와 합성목재의 두 종류이고, 신발과 접촉하는 데크표면은 데크의 길이 방향으로 홈가공처리를 한 단일 논슬립가공 형태와 길이방향에 더불어 가로방향에 추가로 홈 가공처리를 한 이중 논슬립가공 형태 두 종류이다. 실험에 사용된 신발의 밑창 형태는 더블유형(W형)과 네모형(${\Box}$형)의 두 종류를 사용하였고, 데크 표면의 함수율 상태에 따른 마찰력변화를 알아보기 위하여 대기와 평형을 이룬 건조상태와 수분습윤상태에서 측정하였다. 각각의 조건에서 마찰계수를 결정하고 각각의 인자가 마찰력에 미치는 영향을 분석하였다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 봄 학술발표회 논문집
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• pp.141-148
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• 1998

The chloride attack of the top mat of reinforcing bars is a major cause of deterioration of comcrete deck of plate girder bridges. This is caused by a current design method which requires a top mat of reinforcing bars to resist a negative bending moment in bridge decks. In recently, empirical evidence has indicated that the top transverse reinforcing bars can patially or fully be eliminated without jeopardizing the structural integrity of a deck. So, one of the most efficient way to increase durability of concrete deck of bridges is the development of new design method that reduce or eliminate the top mat reinforcing bars, mad it is possible by the exact analysis that considering the negative bending moment reducing effect which introduced by relative deflection of plate girders. In this study, we develop the new bridge deck analysis method that considered the effect of relative girder deflection by applying the principles of slope deflection method of frames, and that is fine tuned with results of finite element analysis. This new approach evaluate a bending moment in a deck based on the effect of relative girder deflection as well as the magnitude of wheel loads, the girder spacing and stiffness, deck stiffness and the span length

• 대한조선학회 특별논문집
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• 대한조선학회 2013년도 특별논문집
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• pp.60-65
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• 2013

Now days, the demands of new type hull lines and optimum design in relation with the EEDI (Energy Efficiency Design Index) regulation and eco-friendly high efficiency vessel design are mandatory clauses in Euro financial crises era. Therefore, in correlation with the above, we tried to find the optimum results and revealed the alterations of supporting structure for liftable car deck latch on PCTC. Generally, PCTC (Pure Car & Truck Carrier) design has been performed by 2 pillar space model F. E analysis without vehicle loads on liftable car deck to evaluate the structural adaptability. So, we applied mentioned vehicle loads on pillar and side transverse web on model to compare with not applied model and performed the ultimate strength analysis of improved design for the safety evaluation.

• 한국강구조학회 논문집
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• 제20권2호
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• pp.227-236
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• 2008

강합성 교량에서 일반적으로 사용되는 콘크리트는 단위질량이 ${2,300kg/m^{3}}$인 일반콘크리트이다. 그러나 강합성 교량에서 경량콘크리트를 사용한다면 바닥판 자중에 의한 단면력을 감소시킬 수 있어 더욱 경제적인 교량설계가 가능할 것이다. 경량콘크리트를 사용한 강합성 거더 교량에서 적용될 수 있는 바닥판 형식은 크게 현장타설 콘크리트 바닥판과 프리캐스트 바닥판으로 구분할 수 있다. 이 두형식의 바닥판은 시공측면이나 구조적 거동 측면에서 다소 차이가 있어, 바닥판과 강거더를 연결하는 전단연결부도 사용되는 바닥판의 형식에 따라 구조적 거동 특성이 위하여 Push-out 실험을 수행하였다. 또한 베딩층이 있는 프리캐스트 부재에 대해서는 강도감소의 주요한 원인이 되는 베딩층의 균열을 방지하기 위하여 프리캐스트 바닥판과 베딩층 사이에 전단키를 설치하고 베딩층을 횡방향으로 구속시킨 실험체에 대해 실험을 수행하여 그 영향을 평가하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.355-362
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• 2001

This study deals with cracking control of concrete deck in steel-concrete composite bridges according to the concrete slab casting sequences. In correlation studies between casting sequences, time dependent effects of concrete creep and shrinkage are implemented in the analytical model. Finally, the methods of cracking control in terms of concrete slump and relative humidity are suggested to prevent early transverse cracking of concrete slab.