• Steel and Composite Structures
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• 제5권4호
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• pp.259-269
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• 2005

Many slab-on-girder bridges around the world are being assessed because they are approaching the end of their anticipated design lives or codes are permitting higher allowable loads. Current analytical techniques assume that the concrete and steel components act independently, typically requiring full-scale load testing to more accurately predict the remaining strength or endurance of the structure. However, many of the load tests carried out on these types of bridges would be unnecessary if the degree of interaction resulting from friction at the steel-concrete interface could be adequately modeled. Experimental testing confirmed that interface friction has a negligible effect on the flexural capacity of a slab-on-girder beam however, it also showed that interface friction is significant under serviceability loading. This has led to the development of an improved analytical technique which is presented in this paper and referred to as the slab-on-girder mixed analysis service load assessment approach.

• Structural Engineering and Mechanics
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• 제8권1호
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• pp.85-102
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• 1999

With the advent of computer, the finite element method has become a most powerful numerical method for structural analysis. However, bridge designers are reluctant to use it in their designs because of its complex nature and its being time consuming in the preparation of the input data and analyzing the results. This paper describes the development of a computer based finite element model using the idea of eccentric beam elements for the analysis of slab-on-girder bridges. The proposed method is supported by a laboratory test using a reinforced concrete bridge model. Other bridge analytical schemes are also introduced and compared with the proposed method. The main aim of the comparison is to prove the effectiveness of the shell and eccentric beam modelling in the studies of lateral load distribution of slab-on-girder bridges. It is concluded that the proposed finite element method gives a closer to real idealization and its developed computer program, SHECAN, is also very simple to use. It is highly recommended to use it as an analytical tool for the design of slab-on-girder bridges.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1300-1309
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• 2010

In the railway bridges, steel plate girder types are preferred due the high stability. Nevertheless, it has been pointed out that this type of bridge has problems such as, structural damages in the rail and girder seat, noise problem due to impact at the rail joint and excessive vibration. This vibration and/or deflection are mainly because insufficient stiffness of steel plate type of bridge. To resolve these problems, PC-Slab composite plate girder type which has simple process and economic cost, is proposed in this study. The static and dynamic experiment is performed by using the production of actual sized PC-Slab and abandoned steel plate girder. The object of this experiment is to verify the fact that girder stiffness increase and structural safety. The result of the experiment is used to analyze the effect of performance improvement of PC composite plate girder type. Using this method, economic rail maintainers, girder stiffness increase, and also speed/ride improvement even for existing rail could be expected by dynamic performance improvement. Additionally noise due to impact, deflection and vibration caused from long rails can be reduced.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.101-102
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• 2016

Through the story height reducing method, cost saving can be implemented in many aspects. Recently, as one of PC floor system, HCS(Hollow Core Slab) has been applied in many project, and it is proved that it is excellent in productivity, economic efficiency, and workability as well. We developed a new composite beam(ANI Girder) which can be associated with HCS and reinforced with a truss-shape rebar and angle. As a result of actual application on underground parking building with HCS, it is confirmed that this system is effective in workability and story height reducing.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.1171-1176
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• 2005

The latest technical development of steel plate girder railway bridge are developing in ways to maximize its durability of materials in use of high strength steel and efficiency of maintenance and management by the introduction of simplified and standardization ideas. In addition to this, it is also expected to reduce the cost of bridge construction and to simplify the process of bridge manufacturing. Referring to this, composite few plate girder railway bridge is highly recommendable that is very economical with the fine exterior. In this paper, it will analyse the variation of dynamic behavior of existing composite few plate girder railway bridge with ballast caused by modified Slab Track through interpretation of limited enzyme in order to obtain the existing data for improvement of Slab Track system from Ballast Track system. Consequently, it can help maximize economic efficiency and structural capability. As a results, although the natural frequency by modified Slab Track are decreased, it is hardly influencing on the safety of railway bridges. It is also evident in the case of slab deck with a reduced scale in comparison with Ballast Track. Therefore, it is expected to reduce the cost of a railway bridge plan. And, it can expect the synergistic effect of the ensure long term durability of bridge caused by decreased stresses of bottom flange due to reduced dead load. As a result, the analytical study are carried out to investigate the composite few plate girder railway bridge could be the optimal design method for the dynamic safety of a girder section.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.697-706
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• 2011

There are more than 800 railway steel plate girder bridges which are in use and the total length is approximately 50 km. Among these, it shall be pointed out that non-ballast rail systems which lay on wood sleepers are the most critical members. To strengthen this type of structures, mainly two methods have been applied. The first one is the most typical method which is to replace the girders with slab girder system or steel composite girders and to add ballast. It is not uncommon that the construction cost of substructure is more than ten time higher than that of superstructures and even in this case, the structural uncertainty for the substructures is not diminished. To resolve above mentioned problems, new method was developed to rehabilitate railway steel girder bridge by adding PC-slab using transport equipment. Using this method, substructure strengthen is rarely required because the additional weight to the bridge superstructure is only up to 1.0t/m. Also it was possible to save the construction cost by reducing construction duration and by simplifying the construction process. Experimental construction was performed for Jewon bridge and measurements were performed before and after construction to verify the bridge capacity.

• Structural Engineering and Mechanics
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• 제54권2호
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• pp.257-289
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• 2015

Shear connectors are generally used to link the slab and girders together in slab-on-girder bridge structures. Damage of shear connectors in such structures will result in shear slippage between the slab and girders, which significantly reduces the load-carrying capacity of the bridge. Because shear connectors are buried inside the structure, routine visual inspection is not able to detect conditions of shear connectors. A few methods have been proposed in the literature to detect the condition of shear connectors based on vibration measurements. This paper proposes a different dynamic condition assessment approach to identify the damage of shear connectors in slab-on-girder bridge structures based on power spectral density transmissibility (PSDT). PSDT formulates the relationship between the auto-spectral densities of two responses in the frequency domain. It can be used to identify shear connector conditions with or without reference data of the undamaged structure (or the baseline). Measured impact force and acceleration responses from hammer tests are analyzed to obtain the frequency response functions at sensor locations by experimental modal analysis. PSDT from the slab response to the girder response is derived with the obtained frequency response functions. PSDT vectors in the undamaged and damaged states can be compared to identify the damage of shear connectors. When the baseline is not available, as in most practical cases, PSDT vectors from the measured response at a reference sensor to those of the slab and girder in the damaged state can be used to detect the damage of shear connectors. Numerical and experimental studies on a concrete slab supported by two steel girders are conducted to investigate the accuracy and efficiency of the proposed approach. Identification results demonstrate that damages of shear connectors are identified accurately and efficiently with and without the baseline. The proposed method is also used to evaluate the conditions of shear connectors in a real composite bridge with in-field testing data.

• 대한토목학회논문집
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• 제31권2A호
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• pp.51-58
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• 2011

이 연구는 중소경간 교량상판의 구조적 효율성과 경제성을 향상시키고 시공시 환경오염이나 교통흐름을 방해할 수 있는 공정을 최소화하기 위한 새로운 형식의 Inverted-T형 거더(이하 IT거더)의 개발을 위한 시험연구이다. 이 공법은 기존의 교량형식보다 미관이 아름답고, 시야확보가 우수한 합성교량상판의 형식으로서 최근 국내 현장에서 당면하고 있는 기능 인력의 고령화로 인한 인력 수급의 어려움을 해결할 수 있는 방편의 하나이다. 따라서 중소경간 교량상판의 설계와 시공을 위한 새로운 IT거더 공법은 시공성 향상과 건설비용 절감을 위한 효과적인 방법으로 사료된다.

• 한국산학기술학회논문지
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• 제8권5호
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• pp.1186-1191
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• 2007

본 연구는 교차형 와이드 거더를 이용한 건축구조로 최소한의 슬래브 두께로 가능한 최장의 스팬을 확보할 수 있도록 함으로써, 층고를 높이지 않으면서 실내 공간에 자유롭고 다양한 변화를 가져올 수 있도록 하는 것이다. 즉, 본 연구는 교차형 와이드 거더를 응력분포에 따라 일정 간격으로 연속 배치함으로써, 낮은 층고에서 해당 경계 공간을 무주 공간으로 형성시킬 수 있도록 하는 것이다 본 연구의 수치적 타당성을 검토하기 위하여 3차원 횡력 설계가 가능한 프로그램인 Midas Gen을 이용하여 기존의 벽체 시스템과 교차형 Wide Girder에 의한 연성골조 시스템을 해석한 결과, 구조적으로 횡변위 및 층간변위와 바닥의 처짐 등이 기존의 벽체시스템과 비교하여 크게 불리하지 않으며, 전체적인 콘크리트 물량이 기존 벽체시스템과 비슷하며 건축적인 가변성을 확보하는데 큰 장점이 있는 것으로 나타났다.

• Computers and Concrete
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• 제23권5호
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• pp.329-334
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• 2019

Traffic flow capacity of some old road bridges is insufficient due to limited deck width. In such cases bridge deck widening is a common solution. For multi-girder reinforced concrete (RC) bridges it is possible to add steel-concrete composite girders as the new outermost girders. The deck widening may be combined with bridge strengthening thanks to thickening of the existing deck slab. Joint action of the existing and the added parts of such bridge span must be ensured. It refers especially to the horizontal plane at the interface of the existing slab and the added concrete layer as well as to the vertical planes at the external surfaces of the initially outermost girders where the added girders are connected to the existing bridge span. Since the distribution of the added concrete is non-uniform in the span cross-section the structure is particularly sensitive to the added concrete shrinkage. The shrinkage induces shear forces in the aforementioned planes. Widening of a 12 m long RC multi-girder bridge span is numerically analysed to assess the influence of the added concrete shrinkage. The analysis results show that: a) in the vertical plane of the connection of the added and the existing deck slab the longitudinal shear due to the shrinkage of the added concrete is comparable with the effect of live load, b) it is necessary to provide appropriate longitudinal reinforcement in the deck slab over the added girders due to tension induced by the shrinkage of the added concrete.