• The Journal of Engineering Geology
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• v.16 no.3 s.49
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• pp.301-306
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• 2006

Damages of cultural properties is caused by subsidence of foundation relating stone structures. To prevent of these structures, ground monitoring should be achieved certainly. Representative ground subsidence cause is saturated and unsaturated condition that is produced repeatedly by groundwater level fluctuations. It controls role that decrease porosity or effective porosity of soil media. Estimation of physical properties can predict from reaction of dielectric constant. Variations of dielectric constants are measured from physical characteristics change of pore, soil particle, air and water which are consisted to ground. Therefore, ground subsidence monitoring is thought that quantitative measurement is available using dielectric response of media.

• 보존과학연구
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• s.16
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• pp.112-122
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• 1995

TEN-STORIED STONE PAGODA ON THE SITE OFWON-GAKSA(Temple) which is one of three marble pagodas in South Korea, were dated from the thirteenth year of the reign of King Sejo(1467). On the roof and surface of each the stories, there were large amount of the contaminants such as pigeon′s excretions, dust and environmental elements for a long time. The pH of contaminants is not acid, but is 7.2, neutral. To find the species of organic acidscontained in the contaminants and the degree of damaging for a marble pagoda, we analyzed the contaminants using GC-MSD method by the following procedures. Organic acids were extracted by saponifying whole contaminants. After Saponification, the organic acids were mathylated to increase their volatility upon subsequent GC-MSD analysis. The mathyl esters of the organic acids are extracted from the acidified aqueous solution. And the organic extracts were washed with adilute base solution. The washed extract were analyzed by GC(Hewlett Packard 5890)with a nonpolar capillary column(Crosslinked 5% Ph Me Silicone, $50×0.2㎜×0.33\mum$film thickness, USA) and Mass Spectrometric Detector(Hewlett Packard 5970B).As the result, it was found that 12 organic acids were the main compound in pagoda′contaminants, and the amount of organic acid were negligible.

• Journal of Conservation Science
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• v.32 no.4
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• pp.561-570
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• 2016

This research was a technical case study for the authentic restoration of the seven-storied Simgoksa stone pagoda after disassembly and reconstruction using three-dimensional image analysis. During disassembly and reconstruction, the pagoda's properties were analyzed in terms of the overall modification and displacement of the pagoda. Distortion was minimized by ensuring structural stability during the reconstruction process. Also, the original site of the pagoda was examined in order to utilize it fully during rebuilding. Before reconstruction of the pagoda, moss and lichen on the stone surfaces were removed by scientific surface cleaning. The foundation of the pagoda was reinforced with rammed earth than was similar to the original foundation using a mixture of soil and quicklime. The results are expected to provide valuable data for the reconstruction of other stone pagodas.

• Journal of Conservation Science
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• v.27 no.4
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• pp.395-401
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• 2011

After pressurized impregnation treatment, which has been proposed as an effective conservation method for stone cultural property, was executed with methyl metacrylate (MMA), MMA-butyl acrylate (PMB73) mixture and MMA-vinyl trimethoxy silane (PMV5) co-monomer mixture, the physical-chemical properties on the sand stone and the granite impregnated were evaluated. Compared to the case of granite, the impregnation ratios of sand stone showed larger values in the range of 3.2 to 3.7 wt% and these were increased up to 32% when the decompression process was applied to autoclave. The physical properties of sand stone such as anti-moisture property, flexural strength, impact property and ultrasonic velocity were also higher values than those of granite, which can be interpreted by high impregnation ratio resulted in many void within sand stone. The impact failure energy was 1.22 J for PMMA, 1.84 J for PMB73, and 2.8 J for PMV5, respectively. Since the inorganic affinity of treatment agent is more effective than the molecular structure of acrylic agent, PMV5 improved inorganic property indicates the optimum impact property.

• Korean Journal of Heritage: History & Science
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• v.47 no.4
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• pp.74-91
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• 2014

The stone statues in the site of Mireuksaji Temple(Iksan, South Korea) were created after the stone pagoda was built in 639. They, transitional statues between animal sculptures and human shaped statues made from the late Goryeo dynasty until the early Joseon dynasty, were set up at the four corners of the stone pagoda by way of guardians. In the case of three statues, their surfaces were denudated and their iconographies have been indiscernible. However, the one in the southwest clearly shows its iconography. It is inferior in properties to the other three statues in the northwest, the northeast and the southeast respectively, but on the other hand its iconography has been well maintained. The reason is related to exposure to harmful environments; specifically, the retaining wall, built around the stone pagoda in the 17th century, had the southwest statue inside and could naturally worked as a buffer against harmful environments. As a result, for about 400 years there has been difference in weathering conditions between the three stone statues and the southwest statue, which brought denudation, the consequent indiscernibleness of iconography and biological invasion to the three statues, notwithstanding superior properties(northwest statue:$176kgf/cm^2$, northeast statue:$109kgf/cm^2$, southeast statue:$273kgf/cm^2$). In contrast, the southwest statue significantly shows its iconography with black contaminants and granule decomposition, despite inferior properties($133kgf/cm^2$). Defenseless exposure to external environment is not recommended for the stone statues, because it is hard to preserve the extant iconography. Herein lies the application of the data on microclimate around Mireuksaji Temple. As regards the weathering zone in which the stone statues are located, Conservation increases in acidity and frequency as years go by, Hereat, in the approach to the Conservation of stone statues, the first consideration needs to be morphological historicity rather than geographical location.

• Journal of Korean Association for Spatial Structures
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• v.19 no.3
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• pp.41-50
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• 2019

The stone pagoda continued to be damaged by weathering and corrosion over time, and natural disasters such as earthquake are accelerating the destruction of cultural properties. Stone pagoda has discontinuous structure behavior and is very vulnerable to the seismic load acting in lateral direction. It is necessary to analyze various design variables as the contact surface characteristics play an important role in the dynamic behavior of stone pagodas. For this purpose, contact surface characteristics of stone pagoda can be classified according to surface roughness and filler type, and representative model is selected and structural modeling and analysis are performed using the discrete element method. Also, the seismic load according to the repetition period is calculated and the dynamic analysis is performed considering the discontinuous characteristics of the stone pagoda. Finally, the seismic behavior characteristics can be analyzed by the evaluation of stresses, displacements and structural safety.

• Conservation Science in Museum
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• v.15
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• pp.56-65
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• 2014

The face of the Seated Stone Buddha ^{Korean Treasure No.84} of Sinboksa Templesite in Gangneung was contaminated with a glossy resin, spoiling its beauty. The contaminants covered the face, the forehead of the urna, to the bottom of the jaw. FT-IR analysis on a sample of the contaminants identified the substance as cyanoacrylate instant adhesive, which can normally be melted with acetone and removed with a swab. However, given that the surface of the statue was severely weathered from prolonged open-air exposure, alternative removal procedures were considered, to minimize the possibility of physical damage. After research, two removal procedures were utilized: one procedure involving poultices, which had been used to remove graffiti from the Samjeondobi Stele, and one procedure involving steam sterilization, which has been used to remove resin from pottery and porcelain. When both the poultices and steam sterilization were applied together, the resin was removed within twenty-four hours, without physical work using a swab.

• Journal of Conservation Science
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• v.22
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• pp.31-42
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• 2008

A stone cultural heritage often lacks design drawing and detailed geometric informations, thus it becomes more difficult to conservation and restoration. Even though there is active database of detail shape information and numerical measurement for stone monuments, most of the data is in hard-to-utilize two-dimensional images. The new technology developed to overcome this problem is three-dimensional image scanning system. The multi-storied stone pagoda of the Daewonsa temple was analysed with 3D scanning image data then survey map with orientation displacement was evaluated. The difference of each side became apparent with the members of the stone properties was measured, also horizontal and vertical displacement occurred. Horizontal displacement occurred in increasing severity from left to right and from body section to upper part. The 8th roof stones are leaning toward northwest direction due to lateral displacement. The evaluation and measurement of displacement could cause a little errors due to the characteristics uneven surface of stone monuments, computer program and mistakes from the researcher. In future, more precise measurement and stability studies should be done to suggest that accurate data for conservation and understanding of damage condition can be provided.

• Journal of the Mineralogical Society of Korea
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• v.18 no.2
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• pp.83-92
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• 2005

Dissolution rate of minerals may differ from climates configuration, but weathering rate of feldspars is generally proved to be relatively higher The result of geochemical reaction modeling indicates the acid water of pH 4.5 excluding any other variables, was 2.3 times higher than that in ordinary rain of pH 5.7. This result proved that pH is very important factor in preservation of granite cultural properties. To prevent the weathering of stone cultural properties, weathering characteristics of stones should be studied first and constitution of dry environments, using water repellent or oil coating, isolating water which cause chemical weathering reaction like hydration and oxidization should be considered. Considering the long-term reactions between granite and rain, selection of materials, which can bring neutralization and non-oxidization conditions, are very important in using cleaning agents and biological controls.

• Journal of Conservation Science
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• v.32 no.3
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• pp.299-312
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• 2016

The Daehan Uiwon (Historic Site No. 248) in which the predecessor of Seoul National University Hospital is a crucial medical institution that built in the Korean Empire period. One of them, East 1 Affiliated Ward that attached to Daehan Uiwon was built with concrete foundation in 1908 and extended two times in 1935 and 1954. As a result of material scientific analysis for concrete foundation, all of the foundation is composed of mortar and stone aggregates, however, the mixing proportions between the aggregate and the mortar were confirmed to be different with construction periods. To determine the mixing proportion, and physical properties by ultrasonic velocity and rebound hardness, the concrete foundations by construction period were obtained. In result, 1954's mixing proportion of concrete between mortar and stone aggregate indicated the highest ratio of aggregates with 1 : 35, mean value of ultrasonic velocity and unconfined compressive strength were calculated with 450 m/s and 18.92 MPa in 1954's constructions that is the lowest values compared with other times. As a result, the difference characteristics of physical properties by construction periods are possible interpreted with porosities and mixing ratios of stone aggregates.