• Journal of Soil and Groundwater Environment
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• v.14 no.5
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• pp.29-40
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• 2009

In general, understanding groundwater flow in fractured bedrock is critical during tunnel and underground cavern construction. In that case, borehole data may be useful to examine groundwater flow properties of the fractured bedrock from pre-excavation until completion stages, yet sufficient borehole data is not often available to acquire. This study evaluated groundwater discharge rate into Jikri tunnel in Gyeonggi province using hydraulic parameters, groundwater level data in the later stage of tunneling, national groundwater monitoring network data, and electrical resistivity survey data. Groundwater flow rate into the tunnel by means of analytical method was estimated $7.12-74.4\;m^3/day/m$ while the groundwater flow rate was determined as $64.8\;m^3/day/m$ by means of numerical modeling. The estimated values provided by the numerical modeling may be more logical than those of the analytical method because the numerical modeling could take into account spatial variation of hydraulic parameters that was not possible by using the analytical method. Transient modeling for a period of one year from the tunnel completion resulted in the recovery of pre-excavation groundwater level.

• Tunnel and Underground Space
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• v.10 no.3
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• pp.329-343
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• 2000

Rock joint survey consists of measurement of orientation and face mapping for trace informations. We have developed a new alternative approach called rock joint survey system by stereophotogrammetry and image processing to replace the conventional manual method. For the measurement of orientations and face mapping, we applied a stereophotogrammetry and developed two hybrid approaches using image processing techniques, respectively. These methods have advantages in making it possible to measure the orientations of joints and perform face mapping rapidly and objectively in unaccessible and dangerous areas.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.06b
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• pp.119-137
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• 2003

Electrical resistivity is one of physical property of the earth and measured by electrical resistivity survey, electrical resistivity logging and laboratory test. Recently, electrical resistivity Is widely used In determination of rock quality in road and railway tunnel design. To get more reliable rock quality data from electrical resistivity, it needs a lot of test and study on correlation of resistivity and rock quality. Firstly, we did rock property test In laboratory, such as uniaxial compressive strength(UCS), P wave velocity, Young's modulus and electrical resistivity. We correlate each test results and we found out that electrical resistivity has exponentially related to UCS and P wave velocity and linearly related to Young's modulus. And we accomplished electrical resistivity survey in field site and carried out electrical resistivity togging at In-situ area. Also we performed rock classification, such as RQD, RMR and Q-system and we correlate electrical resistivity to rock classification results. We found out that electrical resistivity logging data are highly correlate to RQD, Q and RMR. Also we found out that electrical resistivity survey data are lower than electrical resistivity logging data when there are faults or fractures. And it cause electrical resistivity survey data to lowly correlate to RQD, Q and RMR.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.315-320
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• 2000

An investigation and structural safety analysis was conducted to get the basic data for establishing maintenance strategy of pipe framed greenhouses. The number of greenhouses investigated was 108 in total. Most multi-span greenhouses had narrower width and lower height than the standard 1-2W greenhouse, and most of single-span greenhouses were tunnel type. In multi-span greenhouses, the size and interval of frameworks such as rafter, purline, column, and cross beam were mostly suitable, but frameworks of single-span greenhouses were mostly insufficient.

• Tunnel and Underground Space
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• v.9 no.4
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• pp.283-284
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• 1999

지하에서의 안전성과 광체의 경제적 회수가 광업계의 주요관심분야이다. 지하구조물과 주변 응려의 상호작용으로 채굴로 인한 지진활동(seismicity)이 지하안정성과 생산성에 결정적인 영향을 미치며, 암석절단, 천공, 발파기술 등을 적절하게 사용하는 것이 주요관심의 대상이 된다. 이 들에 대한 기초적인 이해는 석유 생산이나 천공장비 개발 등에도 적용될 수 있다.

• Journal of Power System Engineering
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• v.3 no.1
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• pp.38-44
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• 1999

Subway is one of the most important transportation and its facilities are increased by the drift of population to cities in these days. But heat generation results from lighting, human and traffic increase in subway, half-closed space, gives uncomfortable sense to the subway passengers. Therefore, natural ventilation by piston effect is done to relieve uncomfortable sense. But train wind by piston effect gives uncomfortable sense to the subway passengers, too. So the numerical calculation of inflow and outflow amounts is important to predict thermal environment and reduce train wind. In case of actual survey of train wind in target station, the amount of train wind are about $3100m^3/train$ at the minimum, about $6000m^3/train$ at the maximum, about $4200m^3/train$ on average. When comparison between simulation for train wind prediction and actual survey for accuracy was done train wind prediction program showed similar results.

• Tunnel and Underground Space
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• v.26 no.3
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• pp.201-211
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• 2016

A method for estimating rock joint size distribution using contained traces length distribution from 3D cylindrical window survey was suggested. To reduce the numerical error, an improved technique was applied. The accuracy was verified by referring to Monte-Carlo simulation and it was found that the error can be decreased with suitable gamma values.

• Tunnel and Underground Space
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• v.13 no.4
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• pp.294-303
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• 2003

The structural behaviour of rock mass structure, such as tunnel or slope is critically dependent on the various characteristics of discontinuities. Therefore, it is important to survey and analyze discontinuities correctly for the design and construction of rock mass structure. One inevitable Procedure of discontinuity survey and analysis is joint set identification from a lot of raw directional joint data. The identification procedure is generally done by a graphical method. This type of analysis has some shortcomings such as subjective identification results, inability to use extra information on discontinuity, and so on. In this study, a computer program for joint set identification based on the fuzzy clustering algorithm was implemented and tested using two kinds of joint data. It was confirmed that fuzzy clustering method is effective and valid for joint set identification and estimation of mean direction and degree of clustering of huge joint data through the applications.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.6
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• pp.525-533
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• 2016

The purpose of current tunnel maintenance system in South Korea is safety-based maintenance system for accident prevention, So it is difficult to conduct a strategic maintenance. The development of a new maintenance system can lead to effective investment of limited financial and it's effort is still in progress. In this study, to develop a performance-based assessment method, indexes for assessment are derived taking into account the safety, durability and serviceability. The indexes for performance-based assessment were selected by a literature analysis and a delphi survey. Then the importance among indexes were calculated by the AHP analysis.

• Journal of Animal Environmental Science
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• v.2 no.2
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• pp.103-110
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• 1996

This survey was conducted to investigate the situation of three types of laying hen houses and farmers' awareness of farm automation. Six windowless, three high-rising windowless and four open-sided laying hen houses were surveyed to compare their characteristics, and sixty farmers answered questionnaires. 1. Population density of laying hen was 13.9 birds/m^2$ in open-sided, 28.9 birds/m^2$ in high-rising windowless, and 44.9 birds/m^2$ in windowless laying hen houses. 2. Feeder space was $12{\sim}13.5cm$ in open-sided laying hen houses, but feeder space of windowless and high-rising hen houses was narrower than that of open-sided laying hen houses. 3. Thermal resistance values were $14.6{\sim}18.7\;m^2\;{\circ}C/W$ in wall, #22.0{\sim}23.7\;m^2\;{\circ}C/W$ in roof of windowless and high-rising windowless laying hen houses but the wall of open-sided laying hen houses was only $1.9\;m^2\;{\circ}C/W$. 4. Maximum ventilation capacity was 0.161{\sim}0.326$ cmm/bird in summer. Minimum rate of tunnel Ventilation laying hen houses in winter was $0.013{\sim}0.040$ cmm/bird, but minimum rate of crossflow and high-rising windowless laying hen houses was larger than that of tunnel ventilation houses. 5. One person managed about 8,100 birds in open-sided, and about 23,500 birds in windowless and high-rising windowless laying hen houses. 7. 90.7% of farmers responsed that they want to construct automatized laying hen houses in the future.