• Title/Summary/Keyword: 지하구조

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A study on analysis of tunnel behaviors considering the characteristics of in-situ stress distribution in rock mass (암반응력의 분포특성을 고려한 터널거동 분석에 관한 연구)

  • Part, Do-Hyun;Kim, Young-Geun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.9 no.3
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    • pp.275-286
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    • 2007
  • In construction of a structure in underground space, in-situ stress in rock mass has great effect on the stability of the structure. Especially, the direction and magnitude of rock stress have influence on the excavation method, the choice of support and reinforcement method for establishing the stability of tunnel. Therefore, it is very important to consider the characteristics of in-situ stress in rock mass for tunnel stability analysis. In this study, a reasonable design method for underground structure was reviewed through the case study for tunnel design considering in-situ rock stress. For this purpose, the estimation for SRF (Stress Reduction Factor) as input parameter in rock classification using Q-System and the assesment for tunnel support were studied. Also, considering the characteristics of in-situ rock stress such as the magnitude of K and the direction of principal stress, the parameter studies for tunnel stability analysis were carried out. An improved method was proposed for obtaining the better results in the tunnel stability analysis.

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A Numerical Analysis on the Collapse and Backfill Mechanism of the Abandoned Mine Cavity (폐광의 점진적 파괴 및 뒷채움 효과에 대한 해석적 연구)

  • Lee, Jun-Suk;Bang, C.S.
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.2 no.2
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    • pp.62-71
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    • 2000
  • The abandoned mines causing settlement of the surface above and collapse of the cavities are the major influencing factor on the stability of the nearby underground structures. To prevent the harmful effect, the backfill methods are commonly applied to the cavities although the design criteria and the analysis method are not properly addressed in some cases. An approximate analytical method together with the numerical technique is considered in this study to simulate the gradual deterioration of the rock masses around the cavities and, therefore, the influential zone to the underground structures passing through the cavities. Also considered in this study is the backfill effect on the stability of the rock masses around the cavities. Specifically, the incomplete backfill effect is compared with that of the idealized backfill method by adopting elasto-plastic analysis involving a strain softening material law.

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Analysis of Electromagnetic Radiation from a GPR Antenna by using 3-Dimensional FDTD Method (3차원 FDTD를 이용한 GPR 안테나의 복사 해석)

  • 현승엽;김상욱;김세윤
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.36D no.3
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    • pp.12-18
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    • 1999
  • 3차원 FDTD법을 이용하여 GPR 안테나의 복사 특성을 해석하였다. Bow-tie 안테나 구조에 대해서는 삼각형 countour-path FDTD, 지하와 같은 분산매질에 대한 흡수경계조건으로 dispersive PML, 공기와 지하간에는 다층구조에 대한 최적 PML 부가조건을 적용하여 Bourgeois의 FDTD계산 모형을 개선하였다. 또한 확장 그리드 기법을 적용하여 수치 계산에 필요한 셀 수를 줄일 수 있음을 보였다.

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Application of Harmonic Seismic Sources to Precision Investigation of Underground Geological SDtructure Part 1 (Wave Field generated by Harmonisc Source Attached to the Surface of Elastic Half Space) (조화진원에 의한 정밀지하구조사탐사 I (표면조화진원에 의한반무한 탄성체의 파동장 해석))

  • 하동호
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1999.04a
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    • pp.93-99
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    • 1999
  • 조화진동하는 점진원에 의한 반무한 탄성체의 응답해석을 수행해 탄성체의 임의의 깊이에서의 응답을 나타내는 계산식을 유도했다 이결과는 최근 연구개발이 진행되고 있는 조화진원에 의한 정밀 지하구조탐사에 중요한 이론적 바탕이 된다. 먼저 실용상 중요한 수평가진에 의한 응답을 계산했다 표면에 큰 응답이 표면파의 형태로 발생하지만 수평진원의 에너지 방사형태는 지향성을 가지고 있어 진원아래의 원뿔형의 영역이 크게 여기된다는 사실을 밝혔다.

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Thermal Characteristics with Various Thermal Insulation Types in Basement Structures (지하층 구조체의 단열재 설치방법에 따른 열전달 특성)

  • 이재윤;조동우
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.11
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    • pp.918-927
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    • 2003
  • This study is to analyze thermal characteristics of the basement structures with a non-thermal insulation and various thermal insulations. From the results through the field experiments and computer simulations, the thermal bridges and heat loss is found in non-insulation structure of the basement under the definite depth of ground level. Therefore, the thermal insulation structure should be installed for preventing the heat loss in the basement.

A Method for Assessing Structural Safety of Ground-Support Systems in Underground Rock Cavern (지하 암반 공동내 지보시스템의 구조적 안전성 평가 방법)

  • 장승필;서정문
    • The Journal of Engineering Geology
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    • v.6 no.1
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    • pp.23-31
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    • 1996
  • A stress redistribution process in ground support system is mpdeled taking into consideration of load transfer mechanism of unbalanced load within shotcrete in a rock cavern constructed by NATM. The corresponding analysis model for ground support system is proposed and the elastic behavior of the shotcrete is studied. The effect on the support system due to variation of several design parameters is analysed with the proposed model. The suggested model yields considerably reduced maximum compressive stresses in shotcrete. Both the pressure coefficient in horizontal direction and the elastic modulus of rock mass govern overall responses, whereas the variation of the properties in support system shows a little difference in system responses. Interaction equations for evaluating safety factors for structural members are suggested. The result of this study can be used in the structural safety assessment of underground structures.

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