• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.09a
• /
• pp.622-640
• /
• 2009

원유 비축기지 저장공동과 같이 상하로 긴 형상의 대규모 공동에서 횡방향의 지압이 과도하게 작용하면 천정부의 응력집중과 측벽의 암반 변위가 과도하게 발생하여 저장공동의 불안정 요인이 된다. 특히 지압의 절대 크기가 암반 강도의 일정 비율 이상이 되면 응력 집중에 의한 암반의 취성 파괴를 유발하고, 이러한 현상은 터널 굴착 시 발생하는 파괴음(popping)과, 굴착면에 평행한 형태로 암편이 탈락하는 취성파괴(spalling) 현상을 동반한다. 이 글에서는 대규모 지하저장공동 굴착시 실제 발생한 과지압으로 인한 문제 사례에 대해 소개한다. 저장공동 굴착시 관찰된 암편 및 숏크리트 탈락과 균열 발생 현상을 관찰하고 암반 계측결과 분석을 통해 과지압의 현상을 진단하였다. 과지압 구간의 현재 상태 및 원안 설계안에 대해 연속체 및 불연속체 안정성 해석을 실시하여 문제의 심각성을 평가하였다. 이를 통해 굴착 형상 변경 및 특수 보강 방안을 제안하였으며 제안된 안의 보강효과에 대한 수치해석 평가 결과를 재검토 하였다. 이들 결과를 종합하여 과지압구간 보강안을 도출하였으며 상시 안정성 감시 대책으로 현장 암반의 미소파괴음 계측 방안을 제시하였다.

• Tunnel and Underground Space
• /
• v.23 no.3
• /
• pp.192-202
• /
• 2013

The domestic demand of natural gas has increased continuously due to the sudden rise of oil price and regulations on greenhouse gas to global warming. In order to improve the supply security of natural gas market in Korea, the agreement on supply of pipeline natural gas (PNG) in Russia was signed between Gazprom and Korea Gas Corporation in 2008. If the supply plan of Russian natural gas is realized, underground storage facilities would be required in order to balance supply and demand of natural gas because the gas demand is concentrated in the winter. This study investigated the safety of the storage facility in quantitative way considering several design parameters such as gas pressure, depth of the storage cavern, rock condition and in-situ horizontal stress ratio. Two dimensional stress analyses were conducted using axi- symmetry condition to examine the behavior of cavern depending upon suggested design parameters. Results showed that the factor of safety, defined as the ratio of 'shear strength'/'shear stress', was largely affected by the depth, rock class and gas pressure but was insensitive to the coefficient of lateral pressure(Ko).

• Tunnel and Underground Space
• /
• v.9 no.1
• /
• pp.27-35
• /
• 1999

The characteristics of heat conduction for the heat source boundary like an arch shape cavern are different from those for the semi-infinite or circular boundary which can be driven theoretically. A new form of transient heat conduction equation in rock mass around the arch shape cavern is evaluated with analyzing the pattern of the rock temperature distribution measured at the cold storage pilot plant. The new equation, which is driven by adopting a shape function, $SF=\sqrt{logx_0/log(x_0+x)}$ to the solution for a semi-infinite boundary, has the semi-radial form of temperature variation with distance. And, thermal properties of rock mass are estimated by comparing the rock temperature distributions by this equation with those by measurement. Thermal conductivity and specific heat of rock mass are estimated as giving the difference of 20~25% compared to those of laboratory scale. This difference seems to be caused by discontinuity like joint and water content in rock mass.

• LP가스
• /
• s.87
• /
• pp.13-14
• /
• 2003

주지하시는 바와 같이 2001.7.29부터 15년이상 경과된 지하매몰LPG저장탱크는 주위의 모래를 제거한후 피복을 벗겨 탱크외면검사를 하도록 고시(산자부고시 제2001-12호, 2001.1.29)가 개정된 바 있습니다. 그러나 이러한 검사방법은 여러 가지 문제점이 있어 저희 협회는 그동안 몇차례 이에대한 개선을 요청한 바 있으며, 실제로 탱크 외면의 모래를 제거한 후 검사를 실시한 결과 우려하였던 여러 문제점이 사실로 확인되었기에 첨부와 같이 매몰저장탱크의 재검사방법을 개선해 줄 것을 요청드리오니 긍정적으로 검토.반영하여 주시기 바랍니다.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2011.05a
• /
• pp.69-70
• /
• 2011

본 논문은 사용후핵연료의 장기저장으로 인하여 발생할 처분지연에 대한 경제적 효과를 분석하였다. 분석 결과, 사용후핵연료 장기저장을 통하여 고준위방사성폐기물의 지하처분장 건설을 190년 지연시킬 경우, 2040년에 처분장을 건설할 경우와 비교하여 약 1/3의 비용이 소요되는 것으로 계산되었다. 이러한 결과는 경수로핵연료 2만톤과 CAMDU 1만6천톤을 처분하는 것을 가정하여 순전히 경제적인 관점에서 산출된 결과이다.

• Tunnel and Underground Space
• /
• v.14 no.1
• /
• pp.16-25
• /
• 2004

As underground caverns have many advantages such as safety and operation, they can also be used for gas storage purpose. When liquefied gas is stored underground, the cryogenic temperature of the gas affects the stability of the storage cavern. In order to store the liquefied gas successfully, it is essential to estimate the exact temperature distribution of the rock mass around the caverns. The main purpose of this study is the development of theoretical solution to be able to estimate the temperature distribution around storage caverns and the assessment of the solution. In this study, a theoretical solution and a conceptual model for estimating two and three dimensional temperature distribution around the storage caverns are suggested. Based on the multi-dimensional transient heat transfer theory, the theoretical solution is successfully derived by assuming the caverns shape as simplified geometry. In order to assess the theoretical solution, by performing numerical experiments with this multi-dimensional model, the temperature distribution of the theoretical solution is compared with that of numerical analysis. Furthermore, the effects of the caverns size are investigated.

• Economic and Environmental Geology
• /
• v.43 no.2
• /
• pp.197-205
• /
• 2010

Recently abrupt climate changes have been occurred in global and regional scales and $CO_2$ reduction technologies became an important solution for global warming. As a method of the solution shallow underground thermal energy storage (UTES) has been applied as a reliable technology in most countries developing renewable energy. The geothermal energy system using thermal source of soil, rock, and ground water in aquifer or cavern located in shallow ground is designed based on the concept of thermal energy recovery and storage. UTES technology of Korea is in early stage and consistent researches are demanded to develop environmental friendly, economical and efficient UTES systems. Aquifers in Korea are suitable for various type of ground water source heat pump system. However due to poor understanding and regulations on various UTES high efficient geothermal systems have not been developed. Therefore simple closed U-tube type geothermal heat pump systems account for more than 90% of the total geothermal system installation in Korea. To prevent becoming wide-spread of inefficient systems, UTES systems considering to the hydrogeothemal properties of the ground should be developed and installed. Also international collaboration is necessary, and continuous UTES researches can improve the efficiency of shallow geothermal systems.

• Tunnel and Underground Space
• /
• v.25 no.2
• /
• pp.168-185
• /
• 2015

The thermal-hydrological-mechanical (T-H-M) behavior of rock mass surrounding a large-scale high-temperature cavern thermal energy storage (CTES) at a shallow depth has been investigated, and the effects of hydrological conditions such as water table and rock permeability on the behavior have been examined. The liquid saturation of ground water around a storage cavern may have a small impact on the overall heat transfer and mechanical behavior of surrounding rock mass for a relatively low rock permeability of $10^{-17}m^2$. In terms of the distributions of temperature, stress and displacement of the surrounding rock mass, the results expected from the simulation with the cavern below the water table were almost identical to that obtained from the simulation with the cavern in the unsaturated zone. The heat transfer in the rock mass with reasonable permeability ${\leq}10^{-15}m^2$ was dominated by the conduction. In the simulation with rock permeability of $10^{-12}m^2$, however, the convective heat transfer by ground-water was dominant, accompanying the upward heat flow to near-ground surface. The temperature and pressure around a storage cavern showed different distributions according to the rock permeability, as a result of the complex coupled processes such as the heat transfer by multi-phase flow and the evaporation of ground-water.

• Economic and Environmental Geology
• /
• v.55 no.6
• /
• pp.563-570
• /
• 2022

This study was objected to show the complexity of groundwater flow system in a site-scale area as a design parameter of the groundwater monitoring network for early detection of pollutant leakage from a potential source of groundwater contamination (e.g., storage tank). Around the tanks, three monitoring wells were installed at about 22~25 m deep and groundwater level and temperature had been monitored for 22 months by 2-minute interval, and then compared with precipitation and temperature data from nearby weather station. Annual variation of groundwater level and its response to precipitation event, variation of groundwater temperature and delayed response to that of atmospheric temperature indicate the complexity of groundwater flow and flow paths even in the relatively small area. Thus, groundwater monitoring network for early detection of contaminant leakage should be designed with full consideration of the complexity of groundwater flow system, identified from the detailed hydrogeological investigation of the site.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
• /
• 1996.06a
• /
• pp.79-109
• /
• 1996

In order to transform the underground utility data into the 3-D spatial objects, this thesis defined the type of the 3-D spatial objects and the storage structure of objects, and developed the spatial data transformation system that transforms the 2-D underground utility data into the pre-defined 3-D spatial objects through the Booch Method, an object-oriented development method. For this sake, the relational data model of ARC/INFO and the storage structure are analyzed, as well as the pre-requisites, required for the 3-D visualization of the underground utilities. Also, the 2-D underground utility data, saved in ARC/INFO, were transformed into the ASCII files through the internal pre-processing procedure, then used as the input data of the transformation system. In addition, to develop the transformation system, the object-oriented development methods are studied first and, then, applied to the system analysis and the design procedure with the Booch Method as a development method. Finally, the results of analysis and design procesure are implemented through AML, a ARC/INFO macro language, and C++, an object-oriented programing language. As a result of this study, the 3-D spatial objects that can visualize the 2-D utilities in 3-D, are acquired, and the adaptation of object-oriented development method to the system development procedure enabled an effective development prodedure.