• Journal of Korean Association for Spatial Structures
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• v.18 no.3
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• pp.45-55
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• 2018

The arched stone bridge has been continuously deteriorated and damaged by the weathering and corrosion over time, and also natural disaster such as earthquake has added the damage. However, masonry stone bridge has the behavior characteristics as discontinuum structure and is very vulnerable to lateral load such as earthquake. So, it is necessary to analyze the dynamic behavior characteristics according to various design variables of arched stone bridge under seismic loads. To this end, the arched stone bridge can be classified according to arch types, and then the discrete element method is applied for the structural modelling and analysis. In addition, seismic loads according to return periods are generated and the dynamic analysis considering the discontinuity characteristics is carried out. Finally, the dynamic behavior characteristics are evaluated through the structural safety estimation for slip condition.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.2
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• pp.113-120
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• 2010

Recently, various evaluations concerning structural stability under construction step and completely constructed step have been executed during a Long-span Arch Bridge designing procedure. However, the breakage of cable-hangers of arched bridge in unexpected accident or periodic cable-replacement has not been considered. Therefore, the purpose of this study is that analyzing structural safety of arched bridge when the cable-hangers being fractured by that reasons. Dynamic analysis are performed by idealizing impact load to three types of impact functions as fracturing the cables. Consequently, when the hangers are fractured, the maximum tensile force by dynamic analysis is larger than those by static analysis. Therefore, the dynamic analysis is demanded to accurately obtain the responses for the structural stability with a realistic impact loading model in the breakage and replacement of cable hangers of long-span arched bride. Moreover, the analysis method and results in this study can be used to basic criteria in design.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.2
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• pp.68-81
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• 2014

This study was conducted to identify the spacialty, to illuminate the existence and values of Myeongwoldae(明月臺) and Forest Myeongwol, and to suggest the sustainable usage, preservation and management plans with the purpose of ecological and cultural landscaping characteristic and value identification. The result of the study is as follows. Castle Myeongwol and Port Myeongwol shows the status of Hallim-eup Myeongwol District which is the administrative center of western Jeju as well as is the fortress. Building Wolgyejeongsa and School Woohakdang, the head temple of education and culture, located in Myeongwol District represents the spaciality of Myeonwol-ri which was the center of education. Stand Myeongwol is one of the most representative Confucian cultural landscapes in Jeju Island and the field of communion with nature where scholars enjoy poetries, nature, changgi(Korean chess), and go in the Joseon Dynasty period. It was found that the current relics of Myeongwoldae was recovered through the maintenance project conducted by Youth Group Myeongwol composed with Hongjong-si(洪鍾時) as the center during the Japanese colonial era in 1931. It seems that the stonework of Myeongwoldae composed of three levels in the order of square, octagon, and circle based on the heaven-man unity theory of Confucianism and the octagon in the middle is the messenger of Cheonwonjibang(天圓地方), in other words, between the square-shaped earth and the circle-shaped sky. It is assumed that both Grand Bridge Myeongwol and Bridge Myeongwol were constructed as arched bridges in early days. Bridge Myeongwol is the only arched bridge remaining in Jeju Island now, which has the modern cultural heritage value. In Forest Myeongwol, 97 taxa of plants were confirmed and in accordance with 'Taxonomic Group and Class Criteria of Floristic Specific Plants', eight taxa were found; Arachniodes aristata of FD IV and Ilex cornuta, Piper kadsura, Litsea japonica, Melia azedarach, Xylosma congestum, Richosanthes kirilowii var. japonica, Dichondra repens, Viburnum odoratissimum var. awabuki of FD III. Otherwise, 14 taxa of naturalized plants including Apium leptophylihum which is imported to Jeju Island only were confirmed. In Forest Myeongwol, 77 trees including 41 Celtis sinensis, 30 Aphananthe aspera, two Wylosma congestum, a Pinus densiflora, a Camellia japonica, a Melia azedarach, and an Ilex cornuta form a colony. Based on the researched data, the preservation and plans of Myeongwoldae and Forest Myeongwol is suggested as follows. Myeongwoldae, Bridge Myeongwol, and Forest Myeongwol should be managed as one integrated division. Bridge Myeongwol, an arched bridge which is hard to be found in Jeju Island is a high-standard stonework requiring long-term preservation plans. Otherwise, Grand Bridge Myeongwol that is exposed to accident risks because of deterioration and needs safety diagnosis requires measures according to the result of precise safety diagnosis. It is desirable to restore it to a two-sluice arched bridge as its initial shape and to preserve and use it as a representative local landmark with Stand Myeongwol. In addition, considering the topophsis based on the analysis result, the current name of Jeju Special Self-Governing Province Monument No. 19 'Myoengwol Hackberry Colony' should change to 'Myeongwol Hackberry-Muku Tree Colony'. In addition, the serial number system which is composed without distinction of hackberry and muku tree should be improved and the regular monitoring of big and old trees, specific plants, and naturalized species is required.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.4
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• pp.48-56
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• 2007

This study was to understand the component that affects the formative beauty and to present the direction of bridge design for improving the image of urban landscape to survey the visual effect and landscape Preference by the change of bridge type. The results of this study are as follows. In the results of image analysis by bridge types, the images of one-arch bridges are unique and interesting, whereas more than two successive arched bridge were harmonize, stable, consecutive and regular. In the case of the arch rib, braced-rib arch bridge was assessed that complicated, diverse and interesting more than solid-rib arch bridge. The results of factor analysis on the psychological factor were classified into three categories: orderliness, aesthetic and symbolism. In the results of analysis on psychological factors by bridge types, the orderliness and symbolism were different in the position of path, and the number of arches, too. In case of arch rib, symbolism was different. In the preference analysis, they showed a sensitive reaction in the background of building. In the results of the relativity preference and psychological factor, according to aesthetic, symbolism and orderliness, there was an effect on the background of building. And, there showed the high effect in order of aesthetic, orderliness and symbolism in the background of mountain and building. This study should be objective raw data of the arch bridge design for improving the urban landscape. In the future, aesthetic variables like colors or textures should be considered for more exact evaluation.

• Journal of architectural history
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• v.23 no.1
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• pp.7-19
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• 2014

This study considers the proper repair techniques by examining the most representative repair cases of the Korean arch bridges and proposes the constructional manual which can apply similar occasions. The cases are Seonamsa Seungseongyo and Songgwangsa Geukrockgyo where this researcher had taken part in the repair works. This Study proposes the maintenance construction manual about the performance degradation drew by performance degradation of the both Korean arch bridges in the maintenance process. First, arch bridge maintenance should be carried out in the dry season, when water is impermeable in the bottom surface of the bridge. Moreover, risk factors of the maintenance should be excluded to secure the water vally flow, the bypass and the temporary bridge. Second, prior to repair, it has to precede (1)3D shooting (2)formal examination (3)structure safety test (4)geological and lithic surveys (5)arch curvature establishment and makeshift frame settlement before transformation (6)relationship expert comments. Third, if the baduk and the foundation stones are inevitable to replace due to performance degradation on the foundation, it should use the high quality stones and secure greater stress by extending the standard range. The foundation on irregular rock needs to be flattened and underside on the replaced materials require Grengyijil to deliver the equal loads. Fourth, In the process of dismantling the stones of the arched bridge, it could make heavy weathering degree and not reuse the materials. Charge should converge the expert advices to choose the reuseable, the conservate and the alternative materials, and increase the reutilization of the raw materials by preservation and reinforcement treatments. Fifth, the side wall should be repaired by the rubble work technique which is not able to pile compost satiety, so it must use long depth of masonary stones for reinforcement. It is considered to reinforce the stone wall in shore as much as possible and protect the abutment and the side wall on the upstream for the arch bridge maintenance works.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.3
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• pp.1-12
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• 2019

A bridge is a structure constructed on water or in the air for convenient passage. Compared to other buildings, the building materials and structures of bridge required unique functions to cross the space. It depends on the productivity of the building, the level of science and technology, and the ecological environment of the building site. Also, it has important relationship with functions such as politics, military, economy, and life. Most of the academic research on bridges is focused on research in the field of bridge-building technology, so the study on the landscape aesthetics and history of bridges is lacking. Against this backdrop, the study will be valuable as a accumulation of both countries' understanding of bridge types, history and culture, as well as technical and aesthetic data, by analyzing the bridges located within the palaces of Korea and China. The research method is to analyze the bridge through field survey and literature analysis.. First, the bridges of royal palace of Korea and China are to be classified quantitatively as physical shapes, landscapes, and decorations by comparing the materials, forms, landscapes, and decorative culture of bridges. Second, characteristics, common points, and differences are extracted by classifying bridges of both countries. Also, the results are discussed based on the physical environment or cultural background. This would be worth cross-referencing in the building technology and aesthetics of the two countries. For the first important characteristics of result, main materials of Korean and Chinese palaces are stone. However, the bridge in China's royal palaces is also focused on wood. Second, in terms of form, the bridges in the royal gardens of Korea and China are all based on the beam bridge. However, the specific form, ratio, style of the beam bridge, and airspace of arched bridge are very different. Third, most of the connection methods are focused on the over bridge. It values the convergence with the surrounding landscape. Due to the difference in the area and location of water, the bridge in the Korean palace is more focused on the convergence of the surrounding buildings and plants, while the bridge in the Chinese palace is more concerned about the harmony of hydration. Fourth, the decoration places importance on the artistry and aesthetics of both the bridges in Korea and China. There is a difference in style in the same type of decoration due to culture.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.3
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• pp.313-319
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• 2016

Wolf-Hirschhorn syndrome (WHS), associated with the deletion of the short arm of chromosome 4, causes multiple congenital malformations. Patients suffer from various deformities, including mental and growth disorders, epilepsy, hypotonia, congenital heart defects, and atypical craniofacial features. The "Greek warrior helmet appearance" is the most characteristic feature, with a prominent glabella, high arched eyebrow, broad nasal bridge, and hypertelorism. Cleft lip with or without cleft palate is observed in 30% of patients. Dental structure anomalies also exist including multiple tooth agenesis and over-retained primary molars caused by MSX1 gene impairment, and cone-shaped and taurodontic teeth. This case, a 9-year-old girl with WHS, showed intellectual disability, delayed growth development, previous occurrence of seizures, otitis media, and the typical facial features of WHS. Dental findings included multiple congenital missing teeth, over-retained primary teeth, and severe caries on the primary molars. Dental treatments were performed under general anesthesia. This report documents the characteristics of WHS, including general and oral features, and discusses the importance of oral hygiene and preventive dental management.