• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.6
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• pp.557-564
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• 2014

In this study, we present an algorithm that conducts an unique naming process for the bridge object through the solid object identification focused on 3D straight bridge model. For the recognition of 3D objects, the numerical algorithm utilizes centroid point, and solid object on the local coordination system. It classifies the object feature set by classifying the objects and members based on the bridge direction. By doing so, unique names, which contain the information about span, members and order of the object, were determined and the suitability of this naming algorithm was examined through a truss bridge model and a bridge model with different coordinate systems. Also, the naming process based on the object feature set was carried out for the real 3D bridge model and then was applied to the module on local server and mobile device for real bridge inspection work. From the comparison of the developed naming algorithm based on object identification and the conventional one based on field inspection, it was shown that the conventional field inspection work can be effectively improved.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.3
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• pp.10-18
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• 2024

Vehicle loading is one of the main causes of bridge deterioration. Although WiM (Weigh in Motion) can be used to measure vehicle loading on a bridge, it has disadvantage of high installation and maintenance cost due to its contactness. In this study, a non-contact method is proposed to estimate the vehicle loading history of bridges using deep learning and CCTV images. The proposed method recognizes the vehicle type using an object detection deep learning model and estimates the vehicle loading based on the load-based vehicle type classification table developed using the weights of empty vehicles of major domestic vehicle models. Faster R-CNN, an object detection deep learning model, was trained using vehicle images classified by the classification table. The performance of the model is verified using images of CCTVs on actual bridges. Finally, the vehicle loading history of an actual bridge was obtained for a specific time by continuously estimating the vehicle loadings on the bridge using the proposed method.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.639-642
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• 2011

이 연구에서는 완전 조립식 교량 하부구조의 비선형해석을 위한 전산플랫폼을 개발하였다. 완전 조립식 교량 하부구조의 비선형거동을 정확하게 파악하고 합리적이면서 경제적인 설계기준의 개발을 위한 자료를 제공하는데 그 목적이 있다. 재료적 비선형성에 대해서는 균열콘크리트에 대한 인장, 압축, 전단모델과 콘크리트 속에 있는 철근모델을 조합하여 고려하였다. 사용된 부착 또는 비부착 텐던요소는 유한요소법에 근거하며 프리스트레스트 콘크리트 부재의 콘크리트와 텐던의 상호작용을 구현할 수 있다. 그리고 접합면요소는 세그먼트 접합부의 비탄성거동을 예측할 수 있다. 제안된 해석기법은 수치예제에 대하여 비선형거동을 비교적 정확하게 예측하였다.

• Journal of the Korean Society for Railway
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• v.17 no.4
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• pp.245-250
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• 2014

This paper, as a study for the serviceability design of railway bridges with concrete track, presents the effects of design parameters of tracks and bridges on the forces acting on the rail supports of the track. To calculate the forces acting on the track, an unequal spacing discrete supported model with different spacing of rail supports was induced. Design parameters are the rail support spacing of expansion joints above abutments or piers of bridges, the distance from the support of a girder to the last rail support on the end of the girder, and the number of additional rail supports. The causes of the displacement of track are axial force, unit vertical displacement, and unit rotation. From the analysis, the maximum compressive force and the maximum uplifting force acting on the rail supports were determined and the effects of the rail support spacing on the forces acting on the track were presented.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.97-100
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• 2010

3차원 정보모델에 기반한 설계 자동화 프로그램의 개발은 좀 더 완성도가 높은 설계안을 도출할 수 있는 방안을 제시할 수 있다. 콘크리트 교량의 설계 과정에서 정형화된 구조 검토 단계 부분을 자동화하고 설계자로 하여금 좀 더 창의적인 설계가 가능하도록 지원하는 시스템을 개발하였다. 특히, 3차원 Building Information Modeling 기반의 프리스트레스트 콘크리트 박스 거더교에 대한 설계 자동화 시스템을 개발하였다. 이를 위하여 3차원 렌더링 알고리즘을 사용하여, 사용자가 원하는 단면 위치 및 분류 체계에 따라 설계를 자동으로 수행할 수 있도록 적용하였다. 또한 생성된 도면은 데이터 호환이 가능함으로써, 사용자의 편의성이 향상될 것으로 판단된다. 이는 설계자동화 분야에서 강교에 국한되었던 점을 콘크리트교를 포함한 주요 교량으로 확대하고 설계 성과품으로 3차원 모델을 도출할 뿐 아니라 2차원 도면을 연계하도록 구성하여 토목 엔지니어의 기술력을 향상시킬 것으로 기대된다.

• Journal of Korean Society of Steel Construction
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• v.14 no.6
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• pp.755-763
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• 2002

Multispan simply supported bridges and multispan continuous bridges take a large portion of bridges in Central and Southeastern United Sates. The superstructure of the bridges are supported by steel rocker bearings. In general, the rocker bearings are modeled with ideal rollers or Coulomb fricition in seismic analysis. However, the rocker bearings have rocking action on pintles after rolling some distance. This rocking action may have considerable effect on the seismic performance of bridges. This study compares the effect of expansion rocker bearings models on a multispan simply supported and a multispan continuous bridge. Since the ideal roller model produces larger responses than the rocking model, its use is undesirable. However, the fricition and hardening model does not have much difference from the responses of the rocking model. In addition, the use of the tow models is convenient in seismic analyses of bridges. Although the rocking model can obtain more exact responses, its behavior is complicated and it may induce the conversion problem in time history analysis because it includes the abrupt changing of stiffiness. The friction and hardening model of expansion rocker bearings is therefore recommended in sesismic analysis.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.4
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• pp.421-428
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• 2011

The communication of each others is lack between planing, design, construction and maintenance in domestic construction industry. This problem makes the omission of information and the loss of cost. So, the introduction of BIM can be the solution about that. BIM manages all information generated during all life-cycle of a structure and consequently maximizes the efficiency of utilizing information. This is done through 3D information model associated with a three-dimensional(3D) parametric CAD. This study proposes the seismic analysis process of steel box bridge for structural design of bridge construction project based on BIM. The additional process is needed for the purpose that structural data is inherent in the property information of 3D information model. This process has 3D modeling progress done by using the information decided in design phase. The design document of seismic analysis can be derived with the proposed process to steel box bridge.

• Journal of KIBIM
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• v.1 no.2
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• pp.6-11
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• 2011

In domestic construction industry, there is lack of the communication between planning, design, construction and maintenance. This problem makes the omission of information and the loss of cost. Therefore, the introduction of BIM can be a solution about that. BIM manages all information generated during all life-cycle of a structure and consequently maximizes the efficiency of utilizing information. This is done through 3D information model associated with a three-dimensional(3D) parametric CAD. This study proposes the design process of steel box bridge for structural design work of bridge construction project based on BIM. This process has 3D modeling progress done by using the information decided in design phase. When the subject for the proposed process is superstructure of steel box bridge in construction, the structural calculation sheet can be derived with the structural design process based on BIM.

• Journal of Korean Society of Steel Construction
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• v.18 no.3
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• pp.339-347
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• 2006

This study proposes a double-composite section to enhance the s serviceability of twin-girder railway bridges, especially in terms of the flexural stiffness of the composite section in negative-moment regions. This paper deals with experiments on continuous twin-girder bridge models with 5m-5m span length with the proposed double-composite action. From results of static tests on the bridge models, several design considerations were investigated including effective width, shear connection and ultimate strength of the double-composite concrete slab showed full shear connection, which verified the suggested empirical equation. From the flexural behavior of the double-composite section, the effective width of the bottom concrete slab can be evaluated as that of the concrete slab under compression. The ultimate flexural strength of the bridge models verified the validity of the rigid plastic analysis of the double-composite section. Design guidelines were suggested based on the test results.

• Journal of Korean Society of Steel Construction
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• v.21 no.4
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• pp.403-411
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• 2009

In the present study, nonlinear earthquake analysis was carried out for a steel girder bridge that had been damaged by the 1995 Kobe earthquake. For such analysis, the use of hysteretic models describing flexure-axial and shear-axial interaction was suggested. The models were incorporated into a structural analysis program in terms of the joint elements representing hinge models, and then a simplified analysis scheme using the hinge models was employed for bridge piers. The analytical predictions of the flexure-axial interactive hinge model show a good correlation with those of the detailed fiber element model. In addition, the analytical predictions of the flexure-shear-axial interactive hinge model enable a displacement component to be separately captured. It is thus recognized that the present study can be a useful scheme for the healthy evaluation of the global displacement performance of piers subjected to earthquake excitation.