• Earthquakes and Structures
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• v.18 no.3
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• pp.367-377
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• 2020

Incremental dynamic analysis (IDA) widely uses for the collapse risk assessment procedures of buildings. In this study, an IDA-based collapse risk assessment methodology is proposed, which employs a novel approach for detecting the near-collapse (NC) limit state. The proposed approach uses the modal pushover analysis results to calculate the maximum inter-story drift ratio of the structure. This value, which is used as the upper-bound limit in the IDA process, depends on the structural characteristics and global seismic responses of the structure. In this paper, steel midrise intermediate moment resisting frames (IMRFs) have selected as case studies, and their collapse risk parameters are evaluated by the suggested methodology. The composite action of a concrete floor slab and steel beams, and the interaction between the infill walls and the frames could change the collapse mechanism of the structure. In this study, the influences of the metal deck floor and autoclaved aerated concrete (AAC) masonry infill walls with uniform distribution are investigated on the seismic collapse risk of the IMRFs using the proposed methodology. The results demonstrate that the suggested modified IDA method can accurately discover the near-collapse limit state. Also, this method leads to much fewer steps and lower calculation costs rather than the current IDA method. Moreover, the results show that the concrete slab and the AAC infill walls can change the collapse parameters of the structure and should be considered in the analytical modeling and the collapse assessment process of the steel mid-rise intermediate moment resisting frames.

• Journal of the Korean Society of Hazard Mitigation
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• v.2 no.4 s.7
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• pp.87-95
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• 2002

Because of the gravitation of population toward large cities, a number of buildings have been constructed since 1970's. They have been rapidly deteriorated as time passed by. Therefore the purpose of this paper is to present basic data on private buildings managed by the Seoul Metropolitan Government and to analyse deterioration factors of them as well as interrelation. And then, the results of this paper can be used to establish the policy of managing timeworn buildings. Through this study timeworn masonry buildings occupy the major part of timeworn buildings, which have almost structural instability, especially individual residence. Both structure type and building type have an interrelation with the deterioration grade. The structure grade have an interrelation with occupancy class more than structure type.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.4
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• pp.153-161
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• 2020

This study investigates the recycling potential of demolition waste (DW) according to building structure, while considering economic aspects. For that, this study surveyed 1,034 residential buildings to collect reliable information on demolition waste generation rates (DWGRs). This study suggested a method for operational cost calculation for each stage and carried out an inventory analysis. The economic value of recycled DW materials was also calculated. And then, the recycling potential(RP) was calculated by building structures and waste types. RP by building structure was low (27-40%), and RP was found in the order of masonry-block, wooden, RC and concrete-brick. By type of DWs, the RP of aggregates was considerably lower than 7%, and DWs such as wood, plastics, and metals showed more than 100% RP. Considering the results of this study, In order to improve the RP of buildings and DWs, the diversification of products that recycled waste like aggregates (i.e., mortar, concrete, bricks, blocks, tiles) and the development of high value-added products are considered to be the most urgent problems. Based on the above RP results, this study proposed a more advanced method for life cycle assessment of buildings and demolition waste.

• Korean Journal of Heritage: History & Science
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• v.46 no.4
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• pp.4-23
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• 2013

Songsalli Ancient Tombs of Gongju consists of seven tombs. King Muryeong's tomb, the seventh tomb, is a brick chamber tomb discovered during the drainage works for the fifth and the sixth tombs in 1971. The excavation at the time focused on topographic surveys of the tomb entrance and the inside of the burial chamber as well as collection of the remains. The burial mount survey confirmed the status of some stone slab remaining and lime-mixed soil layers, but the survey did not examine the exterior structure of the whole tomb as the mounds were removed even more deeply. The excavation revealed damages to the bricks and mural damages due to moisture and fungus in the sixth and the seventh tombs. Between 1996 and 1997, Gongju National University conducted a comprehensive detailed survey of Songsalli Ancient Tombs including a geophysical survey, with an aim to identify the root causes of such degradation. Based on the results, repair took place in 1999 and the fifth, sixth and seventh tombs were placed under permanent conservation to conserve the cultural assets. General public is currently denied access. The purpose of this study was to conduct a three-dimensional resistivity and GPR surveys on the ground surface of the fifth, sixth and seventh tombs of Songsalli Ancient Tombs in order to understand the underground status after repair. The study also aimed to understand the thickness of all the tomb walls and exterior structure based on GPR inside King Muryeong's tomb. The exploration on the ground surface found that the three tombs and soil adjacent to the tombs had resistivity as low as 5 to $90{\Omega}m$, which confirmed that the soil water content was still as high as that prior to the repair work. Additionally, GPR found that the wall construction of the burial chamber of King Muryeong's tomb was approximately 70cm in thickness, while the structure was of 2B with two bricks, about 35cm in length, put together longitudinally(2B brick masonry). The pathway to the burial chamber was of the 2B structure just like that of the burial chamber walls, while its thickness was 80cm with an eyebrow-type arch connected to it. Also, the ceiling exterior appears to have an arch structure, identical to the shape inside.

• Korean Journal of Environment and Ecology
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• v.22 no.3
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• pp.268-279
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• 2008

This study is aimed at typifying the crossing structure and inquiring into the characteristics of vegetation distribution by type targeting Dorimcheon(stream), Banghakcheon(stream), Seongnaecheon(stream) and some sections of Yangjaecheon(stream) in Seoul through the establishment of basic data for restoring vegetation in urban stream. This research classified the crossing structure into 56 slope types and 31 vertical types in combination with the three items, such as bank slope(vertical style, slope style) of bank, absence or presence of waterside, and revetment structure. This research derived nine slope types including SB1 (revetment of low water level-revetment with vegetation, and revetment of high water level-nature riverside) including SG5(revetment of low water-concrete, and revetment of high water level-riprap work), and three vertical types, such as VH4(bank revetment-wet masonry), and VH7(bank revetment - concrete )from the target survey areas. Among these, both revetment of low water level and high water level were found to be distributed on the longest section as the type of SG7 and VG7 structured in concrete. As a result of inquiry and analysis of micro topography structure and vegetation structure of eight major types, this research could find out the influence of crossing structure on plant vegetation according to the characteristic by typified item, but there appeared no distinct characteristic of vegetation distribution by crossing structure.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.217-221
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• 2003

This study proposes a new classification system and analysis methodology for time delay risk of apartment projects. And this study proposes the classification of major trades and risk level and risk index by performing expert-oriented interview and survey report on a national scale. The purpose of this study is to present basic data for time delay risk management system through the analysis of risk level, risk index and rank of major 5 trades(earth work, structure work, masonry work, window and door/glass work, and interior finish work) in apartment projects.

• Architectural research
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• v.2 no.1
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• pp.1-6
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• 2000

Ever since Viollet-le-Due began to examine Gothic structural elements using his method of geometrical analysis in the nineteenth century, art and architectural historians and a few engineers have periodically attempted to ascertain the structural advantages of the various characteristic features of Gothic architecture. In none of these studies, however, has the way forces work within the lightweight and spacious masonry Gothic buildings been precisely interpreted. The approach taken by art and architectural historians has therefore tended to be primarily descriptive and to be based on intuitive assumptions. This study intend to analyze the Gothic non-vaulted nef unique(aisleless) structures of Lower Languedoc which has never been scientifically tested, and to provide as comprehensive an explanation as possible of the way in which these non-vaulted buildings work. In order to achieve this goal, this paper Is to examine, by means of finite element analysis. the links between the width of non-vaulted aisleless structures, the configuration of the arches, diaphragm arch, and the buttress. Finite element analysis with a computer provides a more accurate analysis than the methods of analysis that have been heretofore applied to Gothic structures, as well as permits us to visualize the global stress behavior of the structure. Combined with traditional methods of studying historical buildings, therefore, finite element analysis inevitably give us a broader understanding of the processes involved in the design and construction of medieval buildings.

• Earthquakes and Structures
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• v.18 no.4
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• pp.437-449
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• 2020

It is quite apparent that engineering concerns related to the influence of masonry infills on seismic behavior of reinforced concrete (RC) structures is likely to remain relevant in the long term, as infill walls maintain their functionalities in construction practice. Within this framework, the present paper mainly deals with the issue in terms of modal expansion of effective earthquake forces and the resultant modal responses. An adequate determination of spatial distribution of effective earthquake forces over the height of the building is highly essential for both seismic analysis and design. The possible influence of infill walls is investigated by means of modal analyses of two-, three-, and four-bay RC frames with a number of stories ranging from 3 to 8. Both uniformly and non-uniformly infilled frames are considered in numerical analyses, where infill walls are simulated by adopting the model of equivalent compression strut. Consequently, spatial distribution of effective earthquake forces, modal static base shear force response of frames, modal responses of story shears from external excitation vector and lateral floor displacements are obtained. It is found that, infill walls and their arrangement over the height of the frame structure affect the spatial distribution of modal inertia forces, as well as the considered response quantities. Moreover, the amount of influence varies in stories, but is not very dependent to bay number of frames.

• Architectural research
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• v.4 no.1
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• pp.25-31
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• 2002

For more than a hundred years, art and architectural historians, architects, and engineers interested in structure have attempted to interpret Gothic architecture, one of the most technologically complex and sophisticated structural systems in history. Indigenous Gothic, however, such as non-vaulted Gothic in the Lower Languedoc region of southern France, has been largely ignored. This study intends to analyze the Gothic non-vaulted nef unique (aisleless) structures of Lower Languedoc which have never been scientifically tested, and to provide as comprehensive an explanation as possible of the way in which these non-vaulted buildings work. In order to achieve this goal, this paper is to examine, by means of finite element computer analysis, a selected example of an existing building. The church of Notre-Dame de Lamourguier, the earliest surviving example of a Gothic nef unique with wide-span diaphragm arches in Lower Languedoc, is selected. Thus, hypothetical models of diaphragm arch buildings and an existing building as a complete structural system were scientifically analyzed in order to provide a comprehensive explanation of how the non-vaulted nef unique system works. The result of the analysis, allows us better to understand the structural behavior of this type of masonry arcuated system and the processes involved in the design and construction of medieval buildings.

• Journal of the Korean Institute of Rural Architecture
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• v.16 no.1
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• pp.63-70
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• 2014

This study is aimed to represent the streetscape in 1960s' focused on Seong-An street of Cheong-ju through the existing business types and buildings, literature, photo details, and interview of the longest-term householders. Results of this study are as follows : Firstly, the types of 1st-floor shops were diverse with general merchandise, apparel, medical, bank, restaurant, and etc in 1960s'. The present shops of them are 'Dong-kwang lasa', 'Jung-geum dang', 'Cheong-ju pharmacy' including the existing 'the Korea development', 'Korea first', and 'Woori' bank. Secondly, the streetscape around post office looks just as it did in the old 1960s'. In the other section the present typical buildings are 'Namseon pharmacy ', 'Kukje department', 'Samyang shop', 'Daeyang shop', 'Park shop', and etc. These old 3-4story buildings are reinforced concrete in contrasted with the former wooden and masonry in structure, and converted in use and appearance. Thirdly, the streetscape of Seong-An is ultimately represented by presuming the other buildings and equipments through aerial and street photograph in the old 1960s'.