2거더교 PSC 장지간 교량바닥판의 최소두께

이한주(Lee Han Joo),정철헌(Chung Chul Hun) 대한토목학회 2007 대한토목학회논문집 A Vol.27 No.3A

장지간 바닥판을 갖는 강합성 2거더교는 경제성 및 내구성 향상이 가능한 교량 구조 형식의 하나로 주목받고 있다. 개정된 도로교 설계기준에서 장지간 바닥판의 두께에 대한 내용이 신설되었지만 명확한 규정이 없는 실정으로 장지간 바닥판의 두께에 대한 명확한 설계법 확립이 필요하다. 본 연구에서는, 직교이방성을 고려한 유한요소해석을 통해 캔틸레버 바닥판을 고려한 장지간 바닥판의 최소두께를 제안하였다. 연구결과, 제안된 두께를 갖는 바닥판은 처짐, 균열폭, 피로내구성 등 사용성을 확보할 수 있을 것으로 판단된다. 또한, 장지간 바닥판의 두께를 결정짓는 가장 중요한 요소는 바닥판의 처짐으로 나타났으며, 도로교 설계기준의 배력철근 설계법은 장지간 바닥판에서의 배력철근량을 과소평가 할 수 있는 것으로 나타났다. Steel-concrete composite bridges with two-girders, with long span bridge deck slabs, have been regarded as one of the economical as well as durable bridge types. KHBDC updated in 2005 included new requirements for the thickness of long span bridge deck slabs. However, specifications in KHBDC do not provide detailed information for the minimum thickness of long span bridge deck slabs. Therefore, it is necessary to establish a definite specification for the minimum thickness of long span bridge deck slabs. In this study, 3-D finite element analyses considering orthotropy were performed to derive the minimum thickness formula for long span bridge deck slabs. The formula is proposed as a function of cantilever slabs length and deck slabs span length. From the analytical studies, it was shown that the deck slabs with proposed thickness satisfies serviceability in terms of deflection, crack width and fatigue requirements. Besides, the deflection limit governs the minimum thickness of long span bridge deck slabs and design method for distribution reinforcement in the current specification can underestimate the amount of distribution reinforcement in the long span bridge deck slabs.

1방향 중공관 데크슬래브의 휨 성능에 관한 실험적 연구

김기웅(Kim Kee-Woong),김해룡(Jin Hai-Long),윤혁기(Yun Hyuk-Gee),박해영(Park Hae-Young),박성수(Park Sung-Soo) 대한건축학회 2011 大韓建築學會論文集 : 構造系 Vol.27 No.1

This study was purposed to evaluate the flexural performance of One-way Hollow Deck Slab through a comparison with the solid slab's and to verify the results of the flexural strength by the linear analysis. For this flexural performance tests, a total of 10 full scale specimens was made. One specimen was the case of conventional solid deck slab. Other 9 specimens were made into 3 shapes of hollow deck slabs which were cycled, rectangular, trapezoidal. Each shape of hollow deck slab was made 3 different sizes. From the results of simple beam loading tests, the flexural strength of hollow deck slab had almost same value with the flexural strength of solid slab. Besides, there was not much difference on the flexural strength and the deflection between hollow deck slab and solid slab even hollow deck slab had changed its size. Result of the tests shows that One-way Hollow Deck Slab was an effective system which is reducing the self-weight and maintaining the flexural strength, compared to solid slab.

강합성 2거더교 현장타설 PSC 바닥판의 정적거동

황훈희(Hwang Hoon Hee),조창빈(Joh Changbin),김병석(Kim Byung Suk),이용우(Lee Yong Woo) 대한토목학회 2007 대한토목학회논문집 A Vol.27 No.3A

강합성 2거더교의 효율적인 바닥판 형식으로 주목받고 있는 교축직각방향 프리스트레스트 콘크리트(PSC) 바닥판의 정적재하실험을 수행하고, 장지간화와 프리스트레스의 도입에 따른 파괴형태의 변화 등 정적 거동 특성을 규명하기 위해 결과를 고찰하였다. PSC 바닥판 실험체는 최근의 연구결과를 이용하여 최소수준의 두께를 갖도록 설계되었으며, 장지간 바닥판의 거동이 구현될 수 있는 충분한 교축방향 길이를 확보하기 위해 1/3 축척의 축소모형으로 제작되었다. 실험 결과, 휨과 펀칭전단의 혼합된 형태로 나타나는 장지간 바닥판의 파괴는 프리스트레스 도입으로 인해 전형적인 펀칭전단 형태로 바뀌는 것으로 나타났으며, 극한강도는 프리스트레스의 크기보다 콘크리트 강도에 보다 민감하게 영향을 받는 것으로 나타났다. 또한, PSC 바닥판은 철근콘크리트 바닥판의 최소두께 규정보다 얇은 수준의 두께로도 펀칭파괴에 대해 충분한 구조적 안전성을 확보하고 있는 것으로 나타났다. In this paper, the static behavior of long-span prestressed concrete (PSC) deck slabs under wheel load, including the effects of transverse prestressing and long span length between girders, is studied experimentally. The long-span PSC deck slabs are designed to have the minimum level of slab thickness based on the recent study and long span length between girders for a two-girder composite bridge. The test specimens are scaled to be one third of the actual size to secure enough longitudinal length in the laboratory, which guarantees realistic behavior of the long-span deck slab. Test results show transverse prestressing makes the failure mode of the long-span PSC deck slab changed from flexure-punching mixed to punching shear, but the ultimate strength of the long-span PSC deck slab is more sensitive to concrete strength rather than the amount of prestressing. Test results also indicate the long-span PSC deck slab has enough safety against punching failure in spite of its thickness thinner than the minimum required for RC deck slabs.

친환경 합성구조 시스템의 하프 슬래브 적용에 관한 연구

윤대영 ( Dai Young Yune ),홍원기 ( Won Kee Hong ),윤태호 ( Tae Ho Yoon ) 한국건축시공학회 2010 한국건축시공학회 학술발표대회 논문집 Vol.10 No.2

Some of the preceding studies suggested rahmen apartment utilizing Green Frame composite structure system. Green Frame system consists of pre-cast concrete columns and pre-cast composite beams. Suggested Green Frame apartment uses deck plate RC slabs. However, the deck plate slab is more difficult to ensure concrete quality and more complex to build in comparison with half PC slab. Accordingly, this paper attempted to analyze constructibility and cost-effectiveness of MIR slab among different half PC slab configurations as a solution to supplement the disadvantages of deck plate. We analyzed the pros and cons of deck plate RC and MIR slabs and estimated costs of each slab construction approach to provide an input for cost-effective analysis. In addition, we analyzed the construction process of each construction approach to understand the constructibility of MIR slab. Such analyses found that MIR slab was a viable alternative to deck plate RC slab. This paper will provide useful reference for further studies targeting half slabs that composite structure design of subsequent architectural project will employ.

2거더 강합성교를 위한 장지간 바닥판 설계 휨모멘트

조창빈(Joh Changbin),윤혜진(Yoon Hye Jin),김병석(Kim Byung Suk) 대한토목학회 2007 대한토목학회논문집 A Vol.27 No.1A

2거더 강합성교에 사용할 장지간 바닥판의 설계 휨모멘트는 기존의 단지간 바닥판의 설계 휨모멘트 산정 시 고려하는 바닥판 지간 거리 이외에 다른 인자들의 영향을 고려하여 결정되어야 한다. 거더의 휨강성, 바닥판의 이방성, 전륜과 중륜의 영향, 차선 증가로 인한 재하 차량 수의 증가, 바닥판의 2방향 거동 등과 같이 단지간 바닥판의 설계에서는 지간이 짧아 무시할 수 있었던 것들의 영향이 바닥판 지간이 길어지면서 커지기 때문이다. 이 논문에서는 이러한 인자들을 고려하여 지간 거리 4m~12m 사이의 2거더 강합성교 장지간 바닥판을 대상으로 교축직각방향과 교축방향 설계 휨모멘트식을 제안하였다. 제안식은 합리적인 안전율을 확보하기 위해서 유한요소모델의 매개변수 해석을 바탕으로 한 회귀분석식에 신뢰성이론을 적용하여 유도되었다. 제안된 설계 휨모멘트식을 독립된 2거더 강합성교량의 상세 모델의 해석결과와 비교하여 검증하였고 도로교설계기준의 설계 휨모멘트식과 비교 검토하였다. The long-span deck slab for the two-girder composite bridge has different design bending moments compared to the Short-span deck slab for the multi-girder composite bridge. This is because the effects disregarded in the design of the short-span deck slab become important in the design of the long-span deck slab. Those are the effects of flexural stiffness of the girders, the front and middle wheels, the number of design lanes, and the two-way action of the deck slab. Therefore, for the reasonable design of the long-span deck slab, those effects should be properly considered. This paper proposes, based on the numerical parametric analyses considering those effects, two design bending moment formulas in perpendicular and parallel to bridge axis for the long-span deck slab that has girder span length between 4 m and 12 m. Reasonable margin of safety based on reliability theory is applied to the proposed formulas. The proposed formulas are verified by the results of independent and detailed finite element analyses. The differences between the design formula in the code and the proposed are also discussed.

강섬유보강 콘크리트를 사용한 무배근 연속슬래브의 구조성능

홍건호(Hong, Geon-Ho) 대한건축학회 2015 大韓建築學會論文集 : 構造系 Vol.31 No.8

Slab is one of the most important members in the building structures because it covers the largest area of the building. But, amount of reinforcement in this member is relatively small because of its small supporting loads. And large exposed area in slab can induce the cracks. To improve this characteristics, the new slab system consist of structural deck-plate and fiber reinforced concrete was suggested for improving construction ability and reduction of construction period. Basic concept of this slab system is that structural deck-plate can replace the tensile reinforcing bars and concrete form, and fiber reinforced concrete can replace the temperature reinforcement. But, previous study was limited because it tested only simply supported slab specimens. This study tested various continuous slab specimens to find the applicability of the suggested new slab system without any additional reinforcement. Design concept is that structural design of slab is assumed as simply support slab, but it should keep the negative moment cracks under allowable crack width in service load conditions. Four continuous slab specimens in total were tested for analyzing the flexural strength, stiffness, deflection, crack development and failure pattern. Test results indicated that suggested new slab system appeared to be better flexural capacity and stiffness than normal reinforced concrete slab with negative moment reinforcement. And it can control the cracks under the allowable crack width upto the service and factored loads.

사다리꼴 형상의 경량체를 가진 데크형 중공슬래브의 휨 및 전단성능에 대한 실험적 연구

김필중,김상모,박준혁 한국강구조학회 2017 韓國鋼構造學會 論文集 Vol.29 No.6

In this study, a trapezoidal hollow ball is used, instead of a spherical hollow ball commonly used in void slab, to secure the high hollow ratio in the deck type void slab. The bending and shear performance was measured with consideration for the shape change of the hollow ball. And to confirm the effect of deck plate and truss wire on shear performance, experiments were performed depending on the installation directions of the one-way deck plate. As a result, the bending performance of the deck type void slab with a trapezoidal hollow ball was similar to that of the void slab with a spherical hollow ball. However, according to the data of shear strength examined, the contribution of shear performance enhancement of the truss wire had a more effect on the shear performance of deck type void slab, rather than the influence by changing of the shape of hollow ball. In the previous studies, the shear strength is reduced to about 60%, due to the reduction of the effective section of concrete by installation of hollow ball. But in this experiment, the maximum load of specimen, in which the deck was installed in horizontal direction, so expected to have no influence on the shear performance, was only reduced to about 87%, due to the truss framework of truss wire. 본 연구에서는 데크형 중공슬래브의 중공률을 확보하기 위한 방안으로 기존의 중공슬래브에 일반적으로 사용되는 구형형상의 경량체 대신 사다리꼴 형상의 경량체를 적용하고, 이에 따른 휨 및 전단 내력 성능을 실험을 통해 확인하였으며, 일방향 데크플레이트의 설치방향에 따른 구조특성을 검토하였다. 그 결과 휨내력 측면에서는 기존 구형형상의 경량체를 가진 중공슬래브와 동등한 수준의 성능을 발휘하는것을 확인하였으며, 전단내력 측면에서는 경량체 형상 변화에 따른 차이보다는 데크플레이트의 트러스철선의 기여에 따라 큰 전단내력성능을발휘하는 것을 확인하였다. 중공체 설치시 콘크리트 유효단면의 감소로, 전단 강도가 약 50~60% 정도로 저하된다는 기존 연구에 따른 계산한전단내력값과 비교하였을 때, 폭방향으로 데크를 설치하여 트러스철근이 전단에 영향을 미치지 않을 것으로 가정한 실험체도 트러스철근의트러스프레임 거동에 의한 영향으로 저감 전 값 대비 87%의 성능을 보여 기존 연구에 따른 계산전단내력보다 최대하중이 더 크게 나타났다.

복층터널 중간슬래브 유지관리에 따른 응력분포 특성 분석

조영교,이영훈,박범근,김성민 한국도로학회 2017 한국도로학회논문집 Vol.19 No.6

PURPOSES : The purpose of this study is to investigate the stresses of the middle slab in a double-deck tunnel owing to the slab lift to replace the underlying elastic pads during maintenance workMETHODS: The middle slab was divided into three different sections: typical section, expansion joint section, and emergency passageway section. Finite element analysis models of these three sections of middle slab were developed, and the stress distribution and maximum stresses were obtained using the models when the middle slab was lifted to replace the underlying elastic pads. Various slab lifting methods were examined in this study such as one-, two-, and multiple-point lifts, distributed lifts, and one or both slab side edge lifts.RESULTS: When the slab side edge is lifted, the longitudinal stresses of the slab are almost the same as the principal stresses. This implies that the governing stresses are the longitudinal stresses. The maximum stresses with both-edge lifts are generally smaller than those with one-edge lifts at all three sections of middle slab.CONCLUSIONS: If the middle slab in a double-deck tunnel is lifted for maintenance, the slab should be lifted at multiple points along the longitudinal direction to reduce the tensile stresses.

프리텐셔닝 인장재를 적용한 CAP Deck 합성슬래브의 휨성능 실험

황슬기 ( Seul Ki Hwang ),김교천 ( Gyo Cheon Kim ),최성훈 ( Sung Hoon Choi ),경제환 ( Jae Whan Kyung ),최성모 ( Sung Mo Choi ) 한국복합신소재구조학회 2016 복합신소재구조학회논문집 Vol.7 No.2

These days, the Composite Slabs with Deep Deck plate was commonly used in domestic construction site, and, the application of the Slim Floor system was increased from the Enlargement and High-rise Building. But, Slim Floor system using the Deep Deck was shown safety problem caused by the deflection and local buckling in construction phase when used to more than 6m. Therefore, for solving the problem, the installation of the shores is essential. This study is realize the long span slab without shores from control the deflection through applied the pre-tensioning elements in CAP deck. In addition, by applying the pre-tensioning member as the tensile member of the CAP Deck slab, the pre-tensioning member for the shores tries to be used as the structural member. Accordingly, to determine the flexural performance of the CAP Deck slab through the pre-tensioning force in tensile member, and, the composite effect of the CAP Deck slab by the experiments.

복층 도로터널 중간슬래브의 건설장비 하중에 대한 거동 분석

조영교,박범근,김성민 한국도로학회 2018 한국도로학회논문집 Vol.20 No.5

PURPOSES : The purpose of this study was to investigate the behaviors of the middle slab in a double-deck road tunnel subjected to construction equipment loading from such as a concrete pump car, concrete transmixer, and lifting crane. METHODS: The major construction processes of a middle slab include concrete placement, concrete transportation, and lifting of materials near the emergency passageway section. During the concrete placement, the middle slab is subjected to construction loading due to the presence of the concrete pump car and fully loaded concrete transmixer. During the concrete transportation, the middle slab is subjected to loadings from both the fully loaded and empty concrete transmixer. The emergency passageway section of the middle slab is subjected to crane loading during lifting work. The magnitudes and geometries of these construction loadings are determined and the stresses and deflections of the middle slab under these loadings are analyzed using finite element models of the middle slab. The behaviors of the middle slab under the design truck loadings are also analyzed to compare the results with those under construction loadings. RESULTS : The stresses and deflections of the middle slab under construction loadings are comparable to those under the design truck loadings. Higher stresses can be observed when the concrete transmixers cross paths at the expansion joint section of the middle slab. The behaviors of the middle slab under the construction loadings during concrete placement are very similar regardless of the section types of the middle slab such as the normal, expansion joint, and emergency passageway sections. CONCLUSIONS : When the middle slab is designed, the construction loadings should be considered to determine the primary design loads and to verify the usability of a variety of construction equipment.