• 한국지형학회지
• /
• 제27권2호
• /
• pp.81-97
• /
• 2020

Geopark refers to a single boundary area consisting of a collection of geosites and geotrails, which includes ecological, historical and cultural elements based on geological and geomorphological resources. To ensure the continued development and conservation of existing listed geoparks, it is necessary to carry out an environmental sensitivity analysis of the geopark components by utilizing spatial information from various scales. The objectives of this study are to analyze the environmental sensitivity in Cheongsong UNESCO global geopark in relation with slope disaster using GIS and to understand its spatial distribution in connection with geosites and geotrails. Two types of spatial database were constructed; geosites and geotrails in Cheongsong UNESCO global geopark and spatial data to perform environmental sensitivity. Potential soil loss and slope stability were analyzed to derive environmental sensitivity related to slope hazard. The results showed relatively high environmental sensitivity along the drainage network of Cheongsong UNESCO global geopark. Zonal statistics analysis was conducted for further detailed distribution of environmental sensitivity based on buffer zones of geosites and geotrails. Majority of geological sites, geological trails, Jeolgol gorge~Jusan Pond section in hiking trails, and Dalgi Mineral Spring Site~Artistic Genius Republic of Korea(Jangnankki gonghwaguk) section in road areas show relatively high slope hazard sensitivity within buffer zones.

• 지질공학
• /
• 제19권1호
• /
• pp.1-8
• /
• 2009

지구물리 탐사는 대전대학교에 위치한 자연사면의 상부에서 2개 측선을 실시하였다. 전기비저항 탐사와 탄성파 굴절법 탐사는 천부에 퍼한 지층 경계, 풍화대 지역 및 지질 특성을 파악하기 위해 실시한 반면, AMT 탐사는 비교적 깊은 심도에 대한 정보를 얻기 위해 측선 2에서 병행하였다. 탐사 결과를 보면, 전기비저항 탐사와 탄성파 굴절법 탐사는 찾고자 하는 지질 특성에 관련하여 서로 일치하는 양상으로 나타났으며, AMT 탐사는 전반적인 기반암의 분포와 파쇄대에 대한 영상을 제시하였다. 그러므로 자연사면에서 복합 물리탐사의 적용은 지하 구조에 대해 상세한 정보를 제공하므로, 이를 통해 사면붕괴에 대해 보다 정확한 해석을 할 수 있다.

• 터널과지하공간
• /
• 제7권3호
• /
• pp.191-201
• /
• 1997

Geological and geotechnical surveys, in general, should precede the excavation to ensure the safety of the tunnel and should be followed up according to the various geological condition during the excavation. However actually the standard support patterns which were decided during the design step used be insisted for the whole excavation steps in spite of the various geological conditions. OO tunnel was excavated with NATM and a support pattern type-V in weak rocks. When the tunnel was excavated up to 25m long, the severe displacement was generated in the portal area and the shotcrete was damaged to make the cracks and the tunnel face was totally collapsed. It might happen owing to the one-day heavy rain, but the exact reason for that accident should be found out and the new optimal support patternt needed. Consequently three dimensional numerical analysis was applied for the evaluation of the cause of the tunnel collapse instead of two dimensional analysis, because three dimensional analysis can show better the real field phenomenon than two dimensional analysis in which the load distribution methods are adopted for the tunnel excavation. We could simulate the actual situations with three dimensional finite difference code and propose the new optimal support patterns.

• 자원환경지질
• /
• 제29권5호
• /
• pp.615-622
• /
• 1996

Slope stability analysis was conducted using remote sensing and Geoscientific Information System (GIS) as a part of natural hazard assessment around Chungju area. Landsat TM band 5 and 7 which contain more information about geological structure and geography are chosen and processed to analyse regional geological structure. Through image processing technique such as PCA, HFF, edge detection and enhancement, regional lineament can be mapped and identified. The lineament density map is constructed based on summed length of lineaments per unit area and the study area can be divided into 7 structural domains. Various factors of slope stability analysis such as geology, slope aspect, degree of slope, landcover, water shed as well as characterized structural domain are constructed as a database of GIS. Rating and weighting of each factor for slope stability analysis is decided by considering environmental geological characteristics of study area. Spatial analysis of regional slope stability is examined through overlaying technique of the GIS. The result of areal distribution of slope stability shows that the most unstable area is all over Jaeogae-ni, Hyangsan-ni and Mt. Daedun.

• 지질공학
• /
• 제10권1호
• /
• pp.79-93
• /
• 2000

일반적으로 공동 주변에 분포하고 있는 지질구조는 지하 암반 공동 굴착시 지수, 보강, 지하수 유동 등에 상당한 영향을 주게 되므로 지질구조의 분포 및 특성을 아는 것이 매우 중요하다. 본 연구에서는 거제 지역에 기 시행된 지하 비축시설의 조사, 설계 및 시공자료를 토대로 지질구조와 공동 누수량 상호 관계를 분석한 결과, 본역에 발달하고 있는 주 함수구조대의 방향은 N50∼60W, 경사는 거의 수직이며 인장 단열로서 추정된다. 이 구조대는 양수 시험시 타원형의 장축 방향과 일치하고 N10∼30E 방향의 단열들과 교차하고 있으며, 화강섬록암에서 나타나는 전형적인 장방형 단열계를 나타낸다.

• Structural Engineering and Mechanics
• /
• 제72권2호
• /
• pp.275-291
• /
• 2019

In a super-large underground with "large span and high side wall", it is buried in mountains with uneven lithology, complicated geostress field and developed geological structure. These surrounding rocks are more susceptible to stability issues during the construction period. This paper takes the left bank of Baihetan hydropower station (span is 34m) as a case study example, wherein the deformation mechanism of surrounding rock appears prominent. Through analysis of geological, geophysical, construction and monitoring data, the deformation characteristics and factors are concluded. The failure mechanism, spatial distribution characteristics, and evolution mechanism are also discussed, where rock mechanics theory, $FLAC^{3D}$ numerical simulation, rock creep theory, and the theory of center point are combined. In general, huge underground cavern stability issues has arisen with respect to huge-scale and adverse geological conditions since settling these issues will have milestone significance based on the evolutionary pattern of the surrounding rock and the correlation analyses, the rational structure of the factors, and the method of nonlinear regression modeling with regard to the construction and development of hydropower engineering projects among the worldwide.

• 지질공학
• /
• 제17권4호
• /
• pp.535-544
• /
• 2007

퇴적암에서 발달된 불연속면들은 암반의 공학적 특성들을 결정하는 가장 중요한 인자이다. 이들 불연속면을 기재하는 요소들은 일반적으로 불균질성과 불확실성을 내포하고 있다. 본 연구에서는 이러한 불연속면의 기재요소를 정량적이고 객관적으로 결정하기 위해 확률론적 통계기법을 이용하였다. 울산 일대의 33개의 퇴적암 사면을 선정하여 ISRM(1978)에서 제시한 불연속면의 조사항목을 바탕으로 불연속면의 특성 조사를 수행하였으며, 조사된 항목의 확률분포함수를 분석하여 울산지역 백악기 하양층군 퇴적암류의 지질공학적 특성을 파악하였다.

• Mycobiology
• /
• 제45권3호
• /
• pp.150-159
• /
• 2017

This study analyzed the distribution of endophytic fungi in 3 coastal environments with different climatic, geographical, and geological characteristics: the volcanic islands of Dokdo, the East Sea, and the West Sea of Korea. The isolated fungal endophytes were characterized and analyzed with respect to the characteristics of their host environments. For this purpose, we selected common native coastal halophyte communities from three regions. Molecular identification of the fungal endophytes showed clear differences among the sampling sites and halophyte host species. Isolates were also characterized by growth at specific salinities or pH gradients, with reference to previous geographical, geological, and climate studies. Unlike the East Sea or West Sea isolates, some Dokdo Islands isolates showed endurable traits with growth in high salinity, and many showed growth under extremely alkaline conditions. A smaller proportion of West Sea coast isolates tolerate compared to the East Sea or Dokdo Islands isolates. These results suggest that these unique fungal biota developed through a close interaction between the host halophyte and their environment, even within the same halophyte species. Therefore, this study proposes the application of specific fungal resources for restoring sand dunes and salt-damaged agricultural lands and industrialization of halophytic plants.

• Nuclear Engineering and Technology
• /
• 제42권1호
• /
• pp.9-16
• /
• 2010

Experimental examinations for evaluating fracutres were conducted by using transparent replicas of a single fracture in order to obtain the fracture data to contribute to the methodlogy on how to improve the definitaion of representative parameter values used for a parallel plate fracture model. Quantitative aperture distribution and quantitative tracer concentration data at each point in time were obtained by measuring the attenuation of transmitted light through the fracture in high spatial resolution. the representative aperture values evaluated from the multiple different measurement methods, such as arithmetic mean of aperture distribution measured by the optical method, transport aperture evaluated from the tracer test, and average aperture evaluated from the fracture void volume measurement converged to a unique value that indicates the accuracy of this experimental study. The aperture data was employed for verifying the numerical simulation under the assuption of Local Cubic Law and showed that the calculated flow rate through the fracture is 10%-100% larger than hydraulic test results. The quantitative tracer concentration data is also very valuable for validating existing numerical code for advection dispersion transport in-plane heterogeneous fractures.

• 지질공학
• /
• 제16권4호
• /
• pp.359-371
• /
• 2006

이 연구는 산사태가 발생한 편마암류, 화강암류 및 제3기퇴적암류지역 자연사면의 토층을 대상으로 여러 토질시험을 실시하여 산사태에 영향을 미치는 토층사면의 토질특성을 고찰하였다. 이를 위하여 같은 시기에 집중호우로 인해 많은 산사태들이 발생되었던 지역으로 편마암류인 장흥지역, 화강암류인 상주지역 및 제3기퇴적암류인 포항지역의 산사태현장 및 그와 대비되는 곳의 토층으로 부터 채취한 시료에 대해 물성 및 공학시험을 실시하였다. 산사태자료와 시험결과를 토대로 산사태지역의 토질측성을 파악하고 발생지역과 미발생지역간의 차별성을 분석하였다. 지질별로 다소의 차이는 있으나 산사태발생지역의 토층은 미발생지역에 비해 균등계수와 곡률계수가 더 크고 세립자의 함유비율이 더 높다. 액성한계는 거의 유사한 경향성을 보이나 소성한계는 다른 두 지질에 비해서 편마암이 상대적으로 더 크게 나타났으며, 산사태발생지역의 토층이 더 낮은 연경도를 갖는다. 함수비는 다른 두 지질에 비해서 제3기퇴적암류가 훨씬 큰데, 이는 모암의 광물조성과 토층의 구조 및 풍화양상 등 다양한 토질요소에 영향을 받는다. 3개 지질조건 모두에서 산사태발생지역의 토층이 미발생지역에 비해서 대체로 큰 간극율과 작은 밀도특성을 갖는데, 이는 산사태발생지역의 토층이 미발생지역에 비해 더 불량한 입도분포와 느슨한 지반상태에 있음을 보여주는 것으로, 간극율이 크고 밀도가 작은 토층에서 산사태가 더 쉽게 발생될 수 있음을 의미한다. 그리고 동일한 지질조건인 경우 투수성이 양호한 토층이 산사태에 더 취약한데, 투수성은 입도분포, 간극크기, 흙입자의 거칠기 및 구조 등의 토질특성과 풍화나 퇴적환경 등 지질성인에 영향을 받는다. 한편, 전단특성은 지질조건에 따라 다소의 차이는 있으나 특별하게 구분되지는 않는다. 그러나 모든 지질조건에서 산사태발생지역의 토층이 미발생지역에 비해 전단저항각이 더 작은 것으로 나타남으로써 동일한 지질조건인 경우 전단저항각이 큰 토층은 작은 토층에 비해 산사태에 더 안정한 지반으로 분류된다.