• Title, Summary, Keyword: 공동 간격

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Mechanical Stability Analysis of a High-Level Waste Repository for Determining Optimum Cavern and Deposition Hole Spacing (고준위폐기물 처분장의 최적 공동간격 및 처분공간격을 결정하기 위한 역학적 안정성 해석)

  • 박병윤;권상기
    • Tunnel and Underground Space
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    • v.10 no.2
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    • pp.237-248
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    • 2000
  • Based on the preliminary results from the therm analysis, which is currently carrying, three-dimensional computer simulations using a finite element code, ABAQUS Ver. 5.8, were designed to determine the mechanically stable cavern and deposition hole spacing. Linear elastic modeling for the cases with different cavern and deposition hole spacing were carried out under three different in situ stress conditions. From the simulations, the response of the rock to the stress redistribution after the excavation of the openings could be investigated. Also the optimum cavern and deposition hole spacing could be estimated based on the factor of safety. When the in situ stress determined from the actual stress measurements in Korea were used, the case with cavern spacing of 40m and deposition hole spacing of 3m was in very stable condition, because the factor of safety was calculated as 3.42., When the in situ stress conditions for Sweden and Canada were used, the previous case, they seem to be in stable condition, since the factors of safety are still higher than 1.0. From these results, it was concluded that the rock will not fail even after the stress redistribution.

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A Study on the Efficiency of Water Curtain around the Underground Oil Storage Cavern (지하유류비축공동(地下油類備蓄空洞)에서 Water Curtain의 효율성(効率性)에 관한 연구(硏究))

  • Chung, Hyung Shik;Lee, Ik Hyo
    • Journal of The Korean Society of Civil Engineers
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    • v.3 no.3
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    • pp.87-94
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    • 1983
  • The successful oil storage in the underground cavern is dependent on how to keep the water-tightness around the cavern by the groundwater. If the water-tightness is not secured, gas bubles will leak out and oil migrate to the adjacent empty cavern. An electrical analogy method was employed in studying the influences of the position of horizontal and vertical water curtains, the head of water curtain and the intervals of the cavern spacings and boreholes on the gas leakage and the oil migration into the adjacent empty cavern. The result shows that if the cavern spacing is narrow, the vertical water curtain should be established and if the cavern spacing is more than twice the cavern height, its establishment is not necessary. All the detailed factors required to prevent the oil migration are shown on graphs.

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Stability Analysis of Multiple Thermal Energy Storage Caverns Using a Coupled Thermal-Mechanical Model (열-역학적 연계해석 모델을 이용한 다중 열저장공동 안정성 분석)

  • Kim, Hyunwoo;Park, Dohyun;Park, Eui-Seob;Sunwoo, Choon
    • Tunnel and Underground Space
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    • v.24 no.4
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    • pp.297-307
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    • 2014
  • Cavern Thermal Energy Storage system stores thermal energy in caverns to recover industrial waste heat or avoid the sporadic characteristics of renewable-energy resources, and its advantages include high injection-and-extraction powers and the flexibility in selecting a storage medium. In the present study, the structural stability of rock mass pillar between these silo-type storage caverns was assessed using a coupled thermal-mechanical model in $FLAC^{3D}$. The results of numerical simulations showed that thermal stresses due to long-term storage depended on pillar width and had significant effect on the pillar stability. A sensitivity analysis of main factors indicated that the influence on the pillar stability increased in the order cavern depth < pillar width < in situ condition. It was suggested that two identical caverns should be separated by at least one diameter of the cavern and small-diameter shaft neighboring the cavern should be separated by more than half of the cavern diameter. Meanwhile, when the line of centers of two caverns was parallel to the direction of maximum horizontal principal stress, the shielding effect of the caverns could minimize an adverse effect caused by a large horizontal stress.

Water Tightness around Under-ground Oil Storage Cavern (지하유류비축공동(地下油類備蓄空洞)의 수밀성(水密性)에 관한 연구(硏究))

  • Chung, Hyung Sik;Sun, Yong;Kim, Oon Young
    • Journal of The Korean Society of Civil Engineers
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    • v.2 no.4
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    • pp.33-38
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    • 1982
  • A successful operation of underground oil storage cavern depends on water-tightness around cavern by groundwater. If water-tightness is not secured, gas bubbles would leak out and oil would migrate to an adjacent empty cavern. In this research an electrical analogy method was employed to study the influence of shape of cavern on gas leakage and the required natural groundwater level, relative oil level in two neighboring caverns and cavern spacing to prevent oil migration. The results show that gas leakage is prevented from a cavern with a ceiling of large curvature. The required values of factors to curtail the migration of oil are given on a graph.

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Measurment of Horizontal rebar Spacing in Concrete Specimens Using Radar (레이더를 이용한 콘크리트 시편 내 수평 배근 간격 탐사)

  • 임홍철;김우석
    • Journal of the Earthquake Engineering Society of Korea
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    • v.4 no.2
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    • pp.65-72
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    • 2000
  • 콘크리트 구조물이 지진 등으로 손상을 입었을 때 그 내부 상태를 파악하는 일은 구조물의 안전성 판단에 필요한 중요 과정중 하나이다 손상도 파악에 사용되는 비파괴 검사 방법 중 레이더법은 현재 콘크리트 부재의 두께와 매립된 철근 및 공동 탐사에 적용되고 있다 레이더법은 다른 비파괴 검사 방법에서와 마찬가지로 측정된 신호의 처리와 해석에 따라 그 결과가 좌우된다 . 이논문에서는 상용 레이더 시스템에서 얻어지는 화상 데이트터를 개선하는 방법을 개발하여 철근이 매립된 콘크리트 시편에 적용하였다 실험에 사용된 기편의 크기는 1,000mm(길이)$\times$600mm (폭) $\times$140mm(두께) 이고 철근의 매립깊이는 표면으로부터 철근 중심까지 60mm 이다 레이더 실측 실험에서 철근의 수평배근 간격을 60 90, 120, 150 mm 로 변화시켜 간격탐사가능성을 시험하였다 결과적으로 상용 시스템에 비해 샹상된 판별효과를 나타냈으며 배근 간격이 90, 120, 150mm 인 시편에서 그 간격을 정확히 찾아내었다.

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An Analysis of Complex for a Parking Lot Expansion (주차장 확대를 위한 공동주택 단지특성 분석)

  • Ha, Na;Song, Nak-Hyun;Yoon, Ho-Bin;Lee, Chan-Sik
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • pp.1039-1042
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    • 2007
  • The number of vehicle has been increased due to growth of economy. Consequently, the needs for parking area has been increasing. there is a serious problem in aged-apartments. It result from observing a parking lot law at that times. That is the reason why residents demand parking lot expansion. Parking lot addition is being studied on a lots different standpoint to solve the present parking lot condition. Parking lot expansion is limited by housing complex characteristics. This study analyzed the housing complex characteristics of aged-apartment. It is analyzed that the number of house holders, distance between buildings, and level of site for finding housing complex characteristics. The result are as follows. the complex lower than 300 households is about 35% in the Number of households. The buildings which has a moving distance from 41m to 50 is nearly 23%. Them the 멕스둣 house located on the flat is 82%. This study will become a reference data for the parking lot expansion.

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A Study on the Expansion Joint of Concrete Lining and Duct in a Tunnel (터널 콘크리트 라이닝 및 공동구 신축이음 설치방안에 관한 연구)

  • Son, Moorak;Park, Yangheum;Park, Yunjae;Kim, Jaegyoun;Yoon, Jongcheol
    • Journal of the Korean Geotechnical Society
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    • v.31 no.3
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    • pp.39-50
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    • 2015
  • The installation of the expansion joints in a tunnel concrete lining and duct would minimize the cracking at the location of structural shape and stiffness change, differential settlement, big temperature change, and so on. However, it is difficult to determine the required spacing of the expansion joint in a tunnel concrete lining and duct quantitatively because the spacing is influenced by temperature change, structure construction condition, ground-structure interaction, and etc. Nevertheless, a highway specification (Korea Expressway Corporation, 2012) or a road design manual (Ministry of Land, Transport and Maritime Affairs, 2010) specifies that the expansion joint spacing in a tunnel concrete lining should be installed uniformly smaller than 25 m from the tunnel portals to 50 m inside of a tunnel and elsewhre 20-60 m in a tunnel (because there is no specifcation for a duct it is assumed that a duct follows the specfication of lining). This specification results in several construction and economic problems in relation with a tunnel construction. Accordingly, in order to minimize the problems, this study analyzed both domestic and foreign design standards and specifications. In addition, field test, theoretical and numerical analyses were carried out in relation to the expansion joint in a tunnel lining and duct. The purpose of this study is to reestabilish a criterion for installing the expansion joint in a tunnel concrete lining and duct.

Analysis of Coupling Waveguide and Cavity with Lossy Dielectric (도파관과 손실 유전체를 가진 공동의 결합 해석)

  • Jung, Baek-Ho;Lee, Hwa-Yong;Ryu, Ji-Jun;Yoo, Kwang-Yeon;Kim, Jin-Joong
    • Proceedings of the KIEE Conference
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    • pp.2171-2173
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    • 2000
  • 도파관에서 개구를 통하여 공동으로 마이크로파 전력이 전송되는 구조를 시간영역 유한차분법을 이용하여 해석하였다. 공동 내부에는 손실 유전체가 있으며, 결합 개구면으로부터 전달된 전력을 흡수하는 구조이다. 전원인가 방법으로 미소간격 전원과 프릴 전원 기법을 적용하여 해의 타당성을 확인하였다. 도파관과 공동의 크기 및 개구의 형태에 따라서 전장 분포 산출을 시뮬레이션하였다.

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