• 제목/요약/키워드: geology investigation

검색결과 331건 처리시간 0.02초

Petrographic and Magnetic Fabric Investigation of the Tadaout-Tizi n'Rsas Dyke Swarms in the Eastern Anti-Atlas, Morocco

  • Daoud, Mustapha Ait;Essalhi, Mourad;Essalhi, Abdelhafid;Toummite, Abdeslam
    • 자원환경지질
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    • 제54권6호
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    • pp.629-647
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    • 2021
  • Located in the eastern part of the Anti-Atlas, the Tafilalet region shows numerous dykes and sills that crosscut the Paleozoic terrains. The magmatic structures (dykes and sills) of the Tadaout-Tizi n'Rsas (TTR) anticline is studied here, it located neighboring the main branch of the Anti-Atlas Major Fault (AAMF), known in this location as the Oumejrane-Taouz Fault (OJTF). The N20° to N60° trending dykes crosscut the Paleozoic formations (Ordovician to Devonian), whereas sills are injected into the Silurian and Devonian ones. The dyke swarms of TTR have been studied using the Anisotropy of Magnetic Susceptibility (AMS), petrographic study and structural analyses. The petrographic study of the TTR doleritic dykes shows a dominance of plagioclase feldspars, alkali feldspars, amphiboles, pyroxenes and biotite. The dykes contain also mesotype (natrolite), sphene (titanite), apatite, actinolite and pegmatitic enclaves of biotite, orthoclase feldspars and pelites. Concerning field works, they show the deformation of TTR dykes by the Variscan tectonics events, it is marked by the presence of displacements (strike-slip faults) and cleavages. The Magnetic Susceptibility (MS) measured on magmatic specimens show the dominance of ferromagnetic and paramagnetic minerals. The high values of MS in the dykes are due to the presence of hematite, amphibole, pyroxene and biotite. In addition their magnetic fabric, determined by our AMS study, allows us to reconstitute the tectonic event which affected the magmatic bodies. This one is characterized by a magnetic foliation and a NNW-trending lineation that reflect the Variscan shortening orientation.

자연사면에서 기반암 및 지질특성을 탐지하기 위한 지구물리 조사 (Geophysical Investigation for Detecting a Bedrock and Geological Characterization in Natural Slope)

  • 박종오
    • 지질공학
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    • 제19권1호
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    • pp.1-8
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    • 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.

강원도 신북지역의 지하수 개발을 위한 복합 탐사법의 이용 (Combination Investigation Method for Grounwater Development Around Shinbuk area in Kangwon-Do)

  • 서백수;김영화;한춘호;신성렬
    • 지질공학
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    • 제10권1호
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    • pp.39-50
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    • 2000
  • 강원도 지역은 산악이 많아 농업용수의 개발이 시급하며 연구대상 지역인 춘천시 신북지역은 소양댐 하부지역에 위치하면서 댐의 혜택을 보지 못하고 벼농사를 하고 있다. 특히 고랭지 야채를 개발하고 높은 수익을 올리기 위해서는 지하수와 연관된 지열을 개발하여 추운 겨울에도 보온을 할 수 있는 시스템을 개발하여야 한다. 국내의 지하수는 1960년대부터 농업용수를 위하여 연구되었고 최근에는 지하철, 원자력 발전소와 같은 지하구조물이나 핵폐기물, 유류 지하저장장소와 같은 대단위 지하공사에서도 재해 방지를 위한 지하수맥의 정확한 조사가 요구되고 있다. 본 연구에서는 지하수 탐사를 위하여 전기탐사, 탄성파탐사, 지오레이더 탐사 등 복합탐사법을 적용하였다.

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Mapping Submarine Bathymetry and Geological Structure Using the Lineament Analysis Method

  • Kwon, O-Il;Baek, Yong;Kim, Jinhwan
    • 지질공학
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    • 제24권4호
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    • pp.455-461
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    • 2014
  • The Honam-Jeju, Korea-Japan, and Korea-China subsea tunnel construction projects have drawn significant attention since the early 2000s. These subsea tunnels are much deeper than most existing natural shallow sea tunnels linking coastal areas. Thus, the need for developing new technologies for the site selection and construction of deep subsea tunnels has recently emerged, with the launch of a research project titled "Development of Key Subsea Tunnelling Technology" in 2013. A component of this research, an analysis of deep subsea geological structure, is currently underway. A ground investigation, such as a borehole or geophysical investigation, is generally carried out for tunnel design. However, when investigating a potential site for a deep subsea tunnel, borehole drilling requires equipment at the scale of offshore oil drilling. The huge cost of such an undertaking has raised the urgent need for methods to indirectly assess the local geological structure as much as possible to limit the need for repeated borehole investigations. This study introduces an indirect approach for assessing the geological structure of the seafloor through a submarine bathymetry analysis. The ultimate goal here is to develop an automated approach to the analysis of submarine geological structures, which may prove useful in the selection of future deep subsea tunnel sites.

전기장과 이온교환막을 이용한 토양에서의 중금속 제거에 대한 연구 (A study on the removal of heavy metals from soils using electrokinetic soil processing and ion exchange membrane)

  • 김순오
    • 자원환경지질
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    • 제32권1호
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    • pp.43-51
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    • 1999
  • In order to remediate hazardous waste site, a process of electrokinetically purging chemicals from saturated soil is examined by laboratory experiments. Electrokinetic soil remediation is one of the most promising soil decontamination processes that habe igh removal efficiency and time-effectiveness in low-permeability soils such as clay. Being combined with several mechanisms-electromigration, elec troosmosis, diffusion and electrolysis of water, electrokinetic soil processing can remove non-polar organics as well as ionic contaminants. The objectives of this study are; 1) the exploration of the feasibility of electrokinetic soil processing on the removal of heavy metals, 2) the investigation of applicability to the tailing-soils in aban doned mining area, 3) the examination of effects of soil pH and conductivity on the transport phenomena of elements in soils, and 4) the investigation of the applicability of the ionexchange membrance to the efficient collection of heavy metals removed from contaminated soils. With the result of this study, it is suggested that the removal efficiency is significantly influenced by applied voltage & current, type of purging solutions, soil pH, permeability and zeta potentials of soil. Although further study should be needed, it is possible to collect removed heavy metals with ion-exchange membrance in cathode compartment.

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Field Investigation of Debris Flow Hazard Area on the Roadside and Evaluating Efficiency of Debris barrier

  • Lee, Jong Hyun;Lee, Jung Yub;Yoon, Sang Won;Oak, Young Suk;Kim, Jae Jeong;Kim, Seung Hyun
    • 지질공학
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    • 제25권4호
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    • pp.439-447
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    • 2015
  • In this study, specific sections vulnerable to debris flow damage were selected, and a complete enumeration survey was performed for the sections with debris flow hazards. Based on this, the characteristics of the sections with debris flow hazards and the current status of actions against debris flow were examined, and an efficient installation plan for a debris flow damage prevention method that is required in the future was suggested. The results indicated that in the Route 56 section where the residential density is relatively higher between the two model survey sections, facilities for debris flow damage reduction were insufficient compared to those in the Route 6 section which is a mountain area. It is thought that several sites require urgent preparation of a facility for debris flow damage reduction. In addition, a numerical analysis showed that for debris barriers installed as a debris flow damage prevention method, distributed installation of a number of small-scale barriers facilities within a valley part was more effective than single installation of a large-scale debris barrier at the lower part of a valley.

Case Study of Slope Investigation on the Cretaceous Sedimentary Rocks Using the Geological Cross-Sections

  • Ihm, Myeong-Hyeok;Kim, Woo-Seok;Kwon, Oil
    • 지질공학
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    • 제31권4호
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    • pp.463-478
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    • 2021
  • The subjects of the study are the sedimentary rock slope of the Mesozoic Gyeongsang Supergroup, which has a high risk of failure. The orientation of the slope-face represents a variety of changing characteristics. The rocks of the slope shall be sandstone, siltstone and dacite, and discontinuities shall develop beddings, shear joints, extension joints, and dacite dyke boundary planes. The type and scale of failure varies depending on the type of rock and the strike/dip of the discontinuities, but the toppling failure prevails. Based on the face-mapping data, SMR, physical and mechanical testing of rocks, analysis and review of the stereonet projections and the critical equilibrium analysis, all four representative sections required a countermeasure method because the acceptable safety factor during dry and rainy seasons were far below Fs = 1.5 and Fs = 1.2. After applying the countermeasure method, both the dry and wet conditions of the slope exceeded the allowable safety factor. In particular, the face-mapping data of the slope-face, the geological cross-sections of several representative sections perpendicular to the slope-face, and the critical equilibrium analysis and the presentation of countermeasure methods that have been reviewed based on them are expected to be reasonable tools for the slope stability. In addition, it will be possible to use it as basic data for performance evaluation for slope maintenance.

A Long-Runout Landslide Triggered by Extreme Rainfall in Gokseong, South Korea on 7 August 2020

  • Nam, Kounghoon;Wang, Fawu;Dai, Zili;Kim, Jongtae;Choo, Chang Oh;Jeong, Gyo-Cheol
    • 지질공학
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    • 제32권4호
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    • pp.571-583
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    • 2022
  • On 7 August 2020, a large-scale catastrophic landslide was triggered by extreme rainfall at Osan village, Gokseong County, South Jeolla Province, South Korea. The initiation mechanism of the Gokseong landslide was different from those typical landslides that occurred in South Korea. Despite the relatively low elevation and slope degree, the landslide had a long runout distance of about 640 m over a total vertical distance of 90 m. A detailed field investigation and chemical analysis were conducted to understand the possible mechanisms for the high-speed and long-runout behavior of the landslide. The terrain controlled the motion behavior of the landslide and the seepage was observed at the whole landslide body. The clay-rich soils covered on granite bedrock of the landslide deposition area from the rice paddy field to the landslide crown. The results of this study may provide basic data for further research on the mechanisms for landslide initiation and propagation.

SWAT-MODFLOW를 이용한 영덕 오십천의 지하댐 타당성 연구 (Feasibility Study of a Groundwater Dam in Osibcheon, using SWAT-MODFLOW)

  • 김종태;정일문;김남원;정교철
    • 지질공학
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    • 제21권2호
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    • pp.179-186
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    • 2011
  • 지표수와 지하수의 연계 해석은 지하수 이용에 의한 문제들을 최소화 시킬 수 있다. 본 연구에서는 지하댐 건설 예정지인 경상북도 영덕군 오십천 유역의 현장조사 및 지하수위 분석을 실시하였으며 지표수 및 지하수 연계해석 모형인 SWAT-MODFLOW를 이용하여 지하댐의 지하수위 변화에 대해 해석하였다. 또한 지하댐 건설을 위한 현황분석을 실시하였으며 지하댐 상부에서 양수를 하였을 경우 지하수위 변화를 분석하여 연구지역의 한국형 지하댐 건설에 대한 타당성을 평가하였다.