• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.199-207
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• 2004

In order to develop a safe geological disposal concept for the HLW from the nuclear power plants in Korea, it is necessary to evaluate the safety of the disposal concept in an underground research tunnel in the same geological formation as the host rock mass. The design concept of a research tunnel depends on the actual disposal concept, repository geometry, experiments to be carried at the tunnel, and geological conditions. In this study, geological investigation had been carried out to develop the basic design of the small scale underground disposal research tunnel in KAERI.

• Journal of the Korean GEO-environmental Society
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• v.1 no.1
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• pp.43-50
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• 2000

This paper presents the engineering property of light weight soil made of soil mixed with recycled stylofoam and stabilizer. Recycled stylofoam beads is able to use by lightweight fill materials because it is light, adiabatic, and effective for vibration interception. Especially, recycled stylofoam beads is easy to supply because stylofoam have been recycle item in 1996. In this study, physical and geotechnical properties of the light weight mixed soil(weathered granite soil mixed with Stylofoam Beads) were analyzed by laboratory experiments to examine its suitability for backfill materials. Laboratory tests were performed to evaluated strength, bearing capacity, weight, permeability, microphotograph analysis with variation of mixing ratio. Based on the results, it is concluded that the use of recycled stylofoam beads is acceptable lightweight fill.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.68-75
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• 2000

This paper presents the construction of an ultra-precision machining system and machining experiments using the developed system. The system is composed of air bearing system, granite bed, air pad, and linear feeding mechanism. The cutting conditions have great effect on the surface quality in ultra-precision machining. the ultra-precision machining is mainly processed by several ${\mu}{\textrm}{m}$ depth of cut and feed rate. For this, tools with sharper cutting edge and less tool wear are needed. To satisfy these requirement, diamond is generally used as a tool material for ultra-precision machining. In order to evaluate the cutting characteristics of the PCD and MCD tools on the aluminum alloy, the machining experiments performed using the developed system.

• Bulletin of the Korean Space Science Society
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• 2011.04a
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• pp.31.4-32
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• 2011

The previous KRISS profilometer design used an aluminum profile structure to which a bar-type reference mirror subsystem and the measurement subsystem are mounted. The earlier design suffers from low stiffness as shown from the first resonance mode of 45.1 Hz. The improved mechanical design we describe in this study replaces the aluminium profile structure with a granite structure of $1340{\times}220{\times}230$ in dimension. The finite element analysis results for the revised design show 0.001 degree in probe contact angle variation. The first resonance mode was computed to 91.2 Hz that is much better than 45.1 Hz from the previous design. We describe the improved design, structural analysis results and how these results would satisfy the form accuracy requirement of 1 ${\mu}m$ PV.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.550-555
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• 2005

In vicinity of Seoul, there has been water service tunnel that classified into 1st grade facility by special act for the safety control of public structures and with providing capacity equals to $1,543{\times}10^3$(ton/day) and inner pressure equals to $2.5-3.5kg/cm^2$. In this research, site investigation and stability analysis for water tunnel caused by new construction of road tunnel were carried out. the ground near water tunnel were zoned into spatial area having similar geotechnical characteristics and estimating geotechnical properties for each area. The site for analysis consists of banded biotite gneiss, biotite schist and granite gneiss with spatial non-homogeneity, and for that reason weathering and fault zone were distributed with large scale. It's important thing to consider spatial ground zone and their geotechnical properties properly into stability analysis at design and construction stage. Also, using results of site investigation, stability of existing tunnel have been analyzed for Hydraulic Fracture/Jacking and deformation in detail.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2006.05a
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• pp.53-54
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• 2006

Recently with increasing interest in the operation of life cycle, building remodeling business is spreading like a fashion. Keeping pace with the trend, the present project carried out the remodeling of an existing neighborhood facility into a religious facility based on the concepts of remodeling, reform and renovation. Basic requirements were overcoming spatial limitations, solving structural problems, meeting various functional needs, and securing a spatial size, and the project designed the interior of the building according to these requirements suggested by the owner. To overcome the low floor height of the existing space, the main sanctuary on the 1st floor had the ceiling in the form of a slant and installed indirect lighting into the resulting gaps, maximizing the depth and width of the space visually. The subsidiary sanctuary on the first basement was finished with red bricks, forming an arch using the bricks, to create religious atmosphere. However, considering the low floor height as in the 1st floor and the ceiling even lowered by the arch structure, the arch was formed threefold and the radius of the curvature of the arch was enlarged to secure a spacious feeling. The outer appearance was finished with granite on existing structure to save the cost of construction. In addition to the use of the finishing material, the structure of the arch and the frame of the opening part and the finishing of the walls were expressed with uneven surface in order to avoid the plainness of the appearance.

• Korean Journal of Environmental Biology
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• v.19 no.2
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• pp.101-105
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• 2001

The biodeterioration with blue-green algae has been studied since 1997 up to 2000 in the tomb of King Mooryong in Kongiu, Korea. Biodeterioration in the tomb initially started from the formation of micro-organismic biofilm that had been suggested to make minor changes on the stone surface. This study revealed that the biofilm formed by microorganisms could result in permanent damages on stone cultural properties. The application of a chemical, 'K2Ol', developed by the author successfully removed fouling of biofilm on the surfaces of stone cultural properties. When small pieces of granite stone were embedded in the solution to study the side effects of the chemicals for a period of three months, the mechanical stability was 0.97 compared to control and there was no change in color. Biodeterioration is one of the most harmful factors that decrease the value of stone cultural properties but it may be treated with a development of proper chemicals.

• Journal of the Korean Society of Safety
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• v.21 no.4 s.76
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• pp.85-94
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• 2006

In this study, in order to evaluate the effect of two types of connector systems in reinforced retaining wall, the centrifugal tests for the conventional connector and new settlement connector system were performed. In the centrifugal tests, the aluminum plate for the face was used and the aluminum foil was used as a reinforcement. The granite soil was adopted as a fill. As a result, The settlement reinforced retaining wall reached to the failure at 80g-level. In contrast, the conventional reinforced retaining wall was collapsed at 69g-level. It means that the settlement reinforced retaining wall has the stronger stability than the conventional reinforced retaining wall. In addition, it was shown that the settlement connector system is more effective to release the stress concentration occurred at the face of reinforced retaining wall than the conventional connector system.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.4
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• pp.421-435
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• 2012

Rock excavation (removal) tests are performed with effective parameters using an abrasive waterjet. For verification of the field rock excavation capabilities, the removal performance and level of efficiency are analyzed for hard granite rock in terms of the water pressure, exposure time of the jet, and the standoff distance. In particular, experimental tests are performed with a long standoff distance required condition in the real excavation field. The rock removal performance level changes according to the rock properties. In this study, various rock specimens are used and P-wave velocities are measured in order to determine the correlation between the removal performance and the P-wave velocity. As a result of the experimental study, the effect of waterjet parameters on rock removal is analyzed.

• Journal of the Korean Geophysical Society
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• v.7 no.1
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• pp.31-40
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• 2004

When surveying the cultural heritages especially in the case of stone structures, preserving their original state is of primary importance. For the effective assessment of survey results of stone structure, the dynamic characteristics of that system should be considered. Dynamic characteristics of stone masonry structures depend on several factors such as coefficients of friction, contact conditions, and number of layers of bonding stones. These factors can be estimated by using the dynamic analysis results. This paper describes a method for natural frequency determination of traditional stone arch bridge subjected to compressive force. For this purpose, multi-layered granite brick models of for arch bridge were made and fundamental frequencies corresponding increasing axial forces were measured.