• Journal of Korean Association for Spatial Structures
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• v.22 no.3
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• pp.33-40
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• 2022

Recently, cultural heritages in South Korea gain many interests of restoration and preservation from the government since many of that have been severely damaged during earthquakes. Many previous studies in both terms of experimental and analytical approaches have been done to examine structural behavior and decide appropriate methods of preservation. Being motivated by such researches, this research aims to investigate a religious stone pagoda dated back to the Goryeo Dynasty in Korea. The structure consists of a granite stone foundation and baked bricks, which resembles the shape of traditional pagodas. In order to examine the structural behavior of the pagoda, an analytical model is implemented using ANSYS, a comprehensive engineering simulation platform. For the time history analysis of the pagoda, several earthquake excitations are chosen and input to simulation modeling. Seismic response of the tower such as time domain, natural frequency, modal shapes and peak acceleration measured at each layer are presented and discussed. In addition, the amplification ratio of the tower is calculated from the accelerations of each layer to determine tower stability in accordance with Korean seismic design guide. The determination and evaluation of status and response of the brick tower by simulation analysis play an important role in the preservation of history as well as valuable architectural heritages in South Korea.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.1
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• pp.15-23
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• 2009

Masonry structures that are very strong in compression fail due to the instability of structural shape of geometry rather than the material stress limit. Considering such structural behavior, the use of the limit theorem that focuses on structural collapse mechanisms is more appropriate for the evaluation of the structural safety of stone voussoir arch bridges. This paper is to investigate structural performance of the stone arch bridges constructed using dry construction method in Korea based on the limit theorem and to exploit the result to develop a system for an structural safety margin. It is expected that this study will help us understand structural behavior of stone voussoir arch bridges in Korea. Also, it will provide a guideline to make engineering decision from the viewpoint of the maintenance of cultural heritages.

• Journal of architectural history
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• v.28 no.6
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• pp.43-54
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• 2019

The grade of East Asian architecture is generally classified by the size, the shape of the roof, and the type of bracket set. The craftsmanship of columns, beam, purlin, stylobate, column base stone and paintwork is also a contributing factor for such classifications. These classifications can be found not only in historical documents such as 「Oksajo(屋舍條)」 of 『Samguksagi(三國史記)』 but also in 「house details regulations of residential architecture(家舍規制)」 of Joseon Dynasty. However, there are differences in detailed designs among the same grade of architecture regardless of the classification. In this research, the Palace, the Royal Residence(宮家), and the Jaesil(齋室) are considered as the Palatial Buildings and Royal Residences. And the advanced architectural o details which appear only in the Royal Architectures are defined as the 'The Architectural Crafts as a Code of Manners'. The Architectural Crafts as a Code of Manners is detailed design, which can be seen as fabrication of materials and supplementary factors. The Architectural Crafts as a Code of Manners used in the Palatial Buildings and Royal Residences reveal the types and their historical changes. This research will present a basis for the repair and restoration of cultural heritages to be carried out in the future, and also prevent them from further damages, thus help to preserve the cultural heritages.

• Journal of Conservation Science
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• v.33 no.6
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• pp.467-483
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• 2017

In this study, the degradation properties by temperature stress of $Araldite^{(R)}$ rapid-curing epoxy resin used for inorganic cultural heritages, was identified. The tensile and tensile shear strength of durability decreased for 12,624 hours at temperatures of $40{\sim}60^{\circ}C$. In terms of stability of external stress and temperature, the slow-curing epoxy was superior to the rapid-curing epoxy, and cultural heritage conservation plans should therefore consider the strength and stress properties of restoration materials. Color differences increased for 12,624 hours at temperatures of $40{\sim}60^{\circ}C$, and glossiness decreased. Both color and gloss stability were weak, which necessitates the improvement of optical properties. Thermal properties (weight loss, decomposition temperature, and glass transition temperature) of adhesives are linked to mechanical properties. Interfacial properties of the adherend and water vapor transmission rates of adhesives are linked to performance variation. For porous media (ceramics, brick, and stone), isothermal and isohumid environments are important. For outdoor artifacts on display in museums, changes in physical properties by exposure to varying environmental conditions need to be minimized. These results can be used as baseline data in the study of the degradation velocity and lifetime prediction of rapid-curing epoxy resin for the restoration of cultural heritages.

• 보존과학연구
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• s.29
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• pp.149-162
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• 2008

Because stone cultural heritages in Korea are mostly situated outdoors without any notable protection, there are severe damages from physical, chemical and biological weathering. And this in turn causes deformation and structural damage. To counteract this problem and increase durability, various kinds of conservation materials are used in the conservation and restoration treatment. However, there are not many practical and technological experiments on this subject. Accordingly this research is for analysis of effect for treatment to make use a resin of the ethyl silicate for the granite in Mt. Nam of Gyeongju. It takes a long time to confirm the test result regarding durability and side effects of the conservatives after treatment. So we built up an artificial environment through freezing and melting test, and evaluated the conservation materials. As a result of this experiment, porosity and absorptivity was increased in accordance with processing of freezing and melting test. But other things such as elastic wave speed, elastic modulus, uniaxial compressive strength and tensile strength was decreased. It will make a plan to form a method of research systematically for mechanism and element of weathering and to elicit a correlation among experiment of artificial weathering and practical natural weathering from next research.

• Journal of Conservation Science
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• v.23
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• pp.1-10
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• 2008

Consolidants based on tetraethoxysilane (TEOS) such as alkoxysilanes have been widely used for the consolidation of decaying stone heritages. Low-viscosity alkoxysilanes penetrate inside the decaying stone and polymerize within the porous structure of the decaying stone, significantly increasing the cohesion of the material. However, TEOS-based consolidants suffer from practical drawbacks, such as crack formation of the gel during the drying phase due to the developed capillary force, which is typical for TEOS-based consolidants. We prepared new consolidants TEOS-based consolidants containing flexible (3-glycidoxypropyl)trimethoxysilane (GPTMS) and silica nanoparticles (or polyhedral oligomeric silsesquioxanes (POSS)) in order to reduce capillary force development during gel drying. Since the consolidants should have a good interaction with the component of the stone in order to connect the isolate grains of decaying stone, the adhesion interaction of the developed consolidants on the surface of the granite was macroscopically investigated by the ISO 2409 cross cutting test. The adhesion interaction decreased with the addition of silica nanoparticle and POSS while it increased with the addition of GPTMS in TEOS solution.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.2
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• pp.14-27
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• 2012

This study aimed to discover new types of landscape resources that have not designated as cultural heritages through a survey of the nationwide traditional industrial landscape resources whose original forms have been lost or damaged in the aspect of management and conservation. It also discovered and analyzed the values of the traditional industrial landscape considered to be humanistic and cultural values. Among the traditional industrial landscape resources distributed nationwide, this study mainly investigated Daranginon, Dok-sal(Korean traditional stone fishing weir) and saltern. Make a list of traditional industrial landscape based on the scenic resources and analyzed the value as scenic spot by conducted basic research and field work. In case some resources were highly valued, this study aimed to rediscover the value as a cultural heritage of the traditional industrial landscape that was a basis of our ancestors' lives and has represented our traditional agricultural and fishing activities done by them over a long period of time by exploring the possibilities of being designated as cultural heritages. Continuous discoveries and studies of traditional industrial landscapes, conservation and usage of traditional industrial landscapes by being designated as a cultural heritage required to be done will be required to be done. Also, this study was supposed to be used as a basic data.

• Journal of Conservation Science
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• v.27 no.2
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• pp.201-209
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• 2011

While consolidants based on tetraethoxysilane (TEOS) have been widely used for the consolidation of decaying stone heritages, TEOS-based consolidants suffer from practical drawbacks, such as crack formation of the gel during the drying phase due to the developed capillary force. We have prepared new TEOS-based consolidants containing flexible (3-glycidoxypropyl) trimethoxysilane (GPTMS) in order to reduce capillary force development during gel drying. In this study, we have prepared TEOS/GPTMS-based consolidants containing ETEOS in order to improve the surface hydrophobisity. The physical properties of the TEOS/GPTMS/ETEOS solution with different hydrolysis were compared with those of the commercial products Wacker OH$^{(R)}$. The contact angle of the surface increased with the addition of the ETEOS, which is higher than that of Wacker OH$^{(R)}$. The sol-gel mechanism was manipulated by the degree of hydrolysis as well as the amount of ETEOS. The properties and the applicability of the developed consolidants for the decayed Korean granites are also investigated.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.5
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• pp.87-96
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• 2017

This study focuses on the Andong Hahoe Village and seeks to identify the shape of the walls since the 1970s. The change of walls can be divided into four periods based on characteristics of materials, shape and distribution. The following is a summary of the results: First, In the 1970s, when Andong Hahoe Village was not designated as a cultural heritage, roof tiles hung on the earthen walls in the middle of the village were major forms. On the outside of the village, rice straw and pine needles were put on the earthen walls or bush clover walls were put in place around if walls were not built. Second, after being designated as a cultural heritage in the 1980s, readjustments for cultural heritages were carried out at the primary stage. However, the distribution of cultural heritages and major changes were not determined at this time since readjustments were mainly focused on the renovation of derelict houses or maintenance of infrastructures. Third, in the past the use of stone bricks for the Hahoe Village site had been difficult, but in the 1990s, replacements with soil-stone walls were identified and the usage of roof tiles increased. The portion of earthen walls, which used to be the major form in the prior era, decreased and this seems to have continued until the 2000s. Fourth, via a field survey, it was found that most of Hahoe village walls consisted of soil cement bricks mixed with cement, steel, lime, gravel. etc. Also, the scope of straw-stricken walls and bush clover walls were reduced to a section of area outside of the village. Fifth, from the 1970s to the present, there were changes to the walls in Hahoe Village including an increase in usages of new materials and an expansion of houses with tiled roofs on top in accordance with the replacement of walls of existing houses. Relevant reasons for this have been identified, such as the fading value of Fungsui(風水) and lack of original records, insufficient awareness and expertise in non-building areas, and the relationship between residents on repairing the wall.

• Journal of the Korean earth science society
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• v.33 no.2
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• pp.126-138
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• 2012

Ultrasonic method is widely used for the evaluation of weathering index and of degree of deterioration because it is easily applicable $in$ $situ$. The basic idea of the method is that the ultrasonic velocity decreases as a rock is being weathered. Thus, the difference of ultrasonic velocities between fresh rock and weathered rock indicates the degree of weathering. In this method, the ultrasonic velocity of fresh rock is assumed to be 5,000 m/s. However, this assumption can cause significant errors in estimating weathering index, especially in case that those rocks of the same type have a wide range of ultrasonic velocities such as in Korea. Therefore, we obtained twenty rock specimens and sixty core samples commonly used for stone cultural heritages in Korea, and measured ultrasonic velocities. From the results, we found that the ultrasonic velocities of the same rock type, granite samples range from 3,118 to 5,380 m/s, and that the estimated weathering index can be highly biased if we use the fixed value of 5,000 m/s. We created a database (DB) by combining the measurement data and reported it. We also measured ultrasonic velocities by direct and indirect methods to quantify the calibration coefficient for each sampling site. We found that the calibration coefficients vary widely from site to site (1.31-1.76). Other factors, such as operator bias and temperature did not show any significant effect on errors in ultrasonic velocity measurements. Lastly, we applied our ultrasonic velocity DB and calibration coefficients to a stone cultural heritage, Bonghwang-ri Buddha statue. Our estimation of the weathering index was 0.3, 0.1 smaller than that by conventional method. The degree of deterioration was also different, "moderately weathered", while conventional method gave "highly weathered". Since other independent studies reported that the degree of deterioration of the Buddha statue was "moderately weathered", our estimation seems to be more accurate. Thus our method can help accurately evaluate the weathering index and the conservation planning for a stone cultural heritage.