• Journal of the Korea Institute of Building Construction
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• v.6 no.1 s.19
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• pp.67-72
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• 2006

There are a lot of problem about waterproofing membrane coating for concrete deck of bridge and waterproofing sheets for concrete of deck of bridge because it couldn't confirm waterproofing's defeat after construction. These problems make a waterproofing material damage and condrete deck of bridge damage. So It needs a lot of money for repair work and reinforcement work. Therefor the structure slab of using waterproofing material protect invasion of water. Also, Concrete deck of bridge need a endurance permeability for the reduction repair payment. In this study, An experimental study on the quality standardization test method waterproofing layer on working of live load.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.11a
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• pp.1-5
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• 2005

There are a lot of problem about waterproofing membrane coating for concrete deck of bridge and waterproofing sheets for concrete of deck of bridge because it couldn't confirm waterproofing's defeat after construction. These problems make a waterproofing material damage and concrete deck of bridge damage. So It needs a lot of money for repair work and reinforcement work. Therefor the structure slab of using waterproofing material protect invasion of water. Also, Concrete deck of bridge need a endurance permeability for the reduction repair payment. In this study, An experimental study on the quality standardization test method waterproofing layer on working of live load

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.2
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• pp.239-245
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• 2020

Recently, BIM (Building Information Modeling) are widely being utilized in Construction industry. However, most structures that have been constructed in the past do not have BIM. For structures without BIM, the use of SfM (Structure from Motion) techniques in the 2D image obtained from the camera allows the generation of 3D model point cloud data and BIM to be established. However, since these generated point cloud data do not contain semantic information, it is necessary to manually classify what elements of the structure. Therefore, in this study, deep learning was applied to automate the process of classifying structural components. In the establishment of deep learning network, Inception-ResNet-v2 of CNN (Convolutional Neural Network) structure was used, and the components of bridge structure were learned through transfer learning. As a result of classifying components using the data collected to verify the developed system, the components of the bridge were classified with an accuracy of 96.13 %.

• Journal of KIBIM
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• v.8 no.4
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• pp.34-40
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• 2018

As the number of aged bridges increases, the development of efficient bridge maintenance techniques is becoming more important. Particularly, there have been many studies on digital-twin models of bridges for maintenance and SHM (Structure Health Monitering). However, in order to use the digital-twin model for maintenance of the bridge, the model updating process that matches the structural response between the real bridge and the digital-twin bridge model must be done. This study presents a model updating method that adjusts bridge's stiffness and boundary condition with genetic algorithm (GA) using static displacements and verified proposed updating method through field test on PSC girder bridge. This study also proposes a conceptual idea to construct an efficient bridge maintenance system by applying the updated numerical analysis model to the digital-twin model.

• Smart Structures and Systems
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• v.13 no.6
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• pp.901-925
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• 2014

The reliability of a Bridge management System depends on the quality of visual inspection and the reliable estimation of bridge condition rating. However, the current practices of visual inspection have been identified with several limitations, such as: they are time-consuming, provide incomplete information, and their reliance on inspectors' experience. To overcome such limitations, this paper presents an approach of automating the prediction of condition rating for bridges based on digital image analysis. The proposed methodology encompasses image acquisition, development of 3D visualization model, image processing, and condition rating model. Under this method, scaling defect in concrete bridge components is considered as a candidate defect and the guidelines in the Ontario Structure Inspection Manual (OSIM) have been adopted for developing and testing the proposed method. The automated algorithms for scaling depth prediction and mapping of condition ratings are based on training of back propagation neural networks. The result of developed models showed better prediction capability of condition rating over the existing methods such as, Naïve Bayes Classifiers and Bagged Decision Tree.

• Structural Monitoring and Maintenance
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• v.5 no.2
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• pp.297-311
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• 2018

Plate and shell structure is widely applied in engineering, i.e. building roofs, aircraft wings, ship platforms, and satellite solar arrays. Its vibration problem has become increasingly prominent due to the tendency of lightening, upsizing and flexibility. As a new smart material with great actuating force and toughness, macro-fiber composite (MFC) is composed of piezoelectric fiber and epoxy resin basal body, which can be directly pasted onto the surface of plate and shell and is suitable for vibration control. This paper deduces the actuation equation of MFC coupled plate in different boundary conditions, an equivalent finite element modeling method is proposed which uses MFC actuating force as the applied excitation, and on this basis the active control simulation and experiment of MFC over plate and shell structure vibration are accomplished. The results indicate that MFC is able to implement effective control over plate and shell structure vibration in multi-band range. The comparison between experiment and simulation proves that the actuation equation deduced herein, effective and practicable, can be applied into the simulation calculation of MFC vibration control over plate and shell structure.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.513-516
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• 2007

We introduce a new copolymer alignment film made by bridge-building structure. It is a better film to decrease the image-sticking level in LCD displays. It is noted that the image-sticking was decreased by preventing ion mixing between inter-layers through high hardness. We have investigated the electrical characteristics such as pretilt angle, Residual DC, VHR by changing cure temperature and process delay time conditions of the new alignment film. In this paper, we have investigated the solution for the deep-rooted image defect and incidentally got a contrast ratio improvement by high anchoring force and hardness elevation through the new copolymer alignment film.

• Journal of Korean Association for Spatial Structures
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• v.8 no.4
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• pp.91-100
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• 2008

In this study, the vibration control performance of high-rise building structures connected by a sky-bridge has been investigated. The philosophy of vibration control using sky-bridges is to allow structures with different dynamic characteristics to exert control forces upon one another through sky-bridges to reduce the overall responses of the system. The the high-rise building structure connected by sky-bridge with 49 and 42 stories was used in this study to investigate the displacement, acceleration, reaction of bearings and stress of sky-bridge by analytical methods. To this end, historical earthquakes, an artificial earthquake and wind force time histories obtained from wind tunnel tests were used. Based on the analytial results, the use of sky-bridge can be effective in reducing the structural responses of high-rise buildings against wind and seismic loads.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.4
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• pp.135-142
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• 2020

The new method for evaluating the displacement tolerance of sky-bridges with pin-roller type supports was proposed considering both return period of phase difference between connected buildings and geometrical characteristics of skybridge. Because displacement tolerance is relative value, which is most affected by the phase difference of the connected buildings, the dynamic response of these building with time history analysis should be evaluated. However, the initial phase could not be specified, so the result of displacement tolerance would be varied with respect to initial value. Thus, the tolerance can be reasonably evaluated SRSS calculation with design displacements based on statistical approach and of each building. In addition, the geometrical characteristics of sky-bridge should be considered because the transverse displacement of sky-bridge span causes the shear deformation of the bridge and longitudinal displacement tolerance cannot release the shear deformation. Therefore, the some pin-end support in sky-bridge should have longitudinal displacement tolerance to accommodate the shear deformation. By resolving this shear deformation, it is possible not only to accommodate transverse displacement, but also to avoid the complicated joint details such as both pot bearing and guided supports with shear key.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.7
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• pp.59-68
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• 2018

Salk Institute for Biological studies is widely considered as architectural masterpiece of Louis Kahn's. Its iconic plaza with symmetrical concrete structures, overlooking the Pacific ocean in La Jolla, has been acclaimed as a facade to the sky. Little has been written on Kahn's achievements in the building system integration in order to bridge the gap between technology and design. This paper explores the technical issues, the design intents, and the major building systems to identify the Kahn's integration methods between building systems. The project is analysed into four major systems; structure, mechanical, envelope, and interior system. The integration methods of building systems are investigated in physical, visual, and functional aspects. The most distinguished cases of building system integration are the introduction of the interstitial floors between the laboratories and the creation of the smooth and warm materiality of exposed concrete walls. Kahn proposed open floor plans for the laboratories which are capable of easily adapting to changing needs. He also introduced the interstitial floors which are framed of the vierendeel truss systems and deliberately overlapped the structure systems with the mechanical systems such as ducts, water pipes, and electric conduits. The exposed concrete walls mixed with pozzolan ashes look very much like granite or limestone as the result of the physical and visual integration between structure, envelope, and interior systems.