• Title/Summary/Keyword: geological structure

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Quantitative Analysis on the Structure of Hambaek Syncline (정량적(定量的) 해석(解析)에 의(依)한 함백향사(咸白向斜) 구조(構造) 연구(硏究))

  • Park, Rin Sik;Min, Kyung Duck
    • Economic and Environmental Geology
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    • v.13 no.3
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    • pp.141-158
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    • 1980
  • A geologic structure could be formed through various processes, because there are a number of factors which control the deformation of the Earth's crust. In geology, we could call it geological epistemology to describe exactly a geologic structure, and call it geological logics to infer logically the deforming process through which the geologic structure had been formed. Degree of legitimacy of geological logics depends upon the degree of exactness of geological epistemology. This study described quantitatively 3-dimensional Hambaek Syncline through computer analysis, and examined qualitatively into its deforming mechanism based on the results of 3-dimensional analysis of the structure. Input data for the computer analysis are dips and dip directions of bedding planes of the structure. The Hambaek Syncline disclose a minor fold group of NE-SW or NNE-SSW trend and a large scale fold of E-W trend. The conclusions of this study are as follows: (1) The fold of E-W trend is primary fold $(F_1)$ and the minor fold group of NE-SW or NNE-SSW trend secondary fold $(F_2)$. (2) Hambaek Syncline is cylindrical type fold. (3) Apparent axial trace of Hambaek syncline does not coincide with true axial trace. The apparent axial trace is $N70^{\circ}-80^{\circ}W$ in Gohan and Sabuk area, and changes to $N70^{\circ}-80^{\circ}E$ in the westward of the area, while the true axial trace is $N40^{\circ}-70^{\circ}W$ in the former, and $N60^{\circ}-80^{\circ}E$ in the latter area. (4) Westward dipping of axial plane of the minor fold group of NE-SW or NNE-SSW trend can be attributed to simple shear movements along overthrusts. (5) Angle between axial trace and the directional trace of the maximum principal compressive stress $({\sigma}_1)$ may not be perpendicular each other. The angle between them is governed by the following factors; 1) the plunge of fold axis 2) the dip of axial surface 3) cylindrisity (6) The mean axial trace of Hambaek Syncline $(F_1)$ is $N45.6^{\circ}W$, and the directional trace of ${\sigma}_1$ is $N52.4^{\circ}E$ (7) The mean axial trace of the minor fold group of NE-SW or NNE-SSW trend $(F_2)$ is $N21^{\circ}E$, and the directional trace of ${\sigma}_1$ is $N22^{\circ}W$.

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Case Study on the Mitigation of Dangerous Slope Considering the Value of Geoheritage (지질유산 가치를 고려한 위험비탈면 보존 방안 사례 연구)

  • Jeong, Jun-Ho;Kim, Seung-Hyun;Park, Byung-suk;Woo, Yong-Hoon;Kang, Yun-seok;Koo, Ho-bon;Son, Moon
    • The Journal of Engineering Geology
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    • v.30 no.1
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    • pp.71-84
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    • 2020
  • Various geological structures are found on the slope of Bangnim district in Pyeongchang, Gangwon-do, based on the Paleozoic Joseon Supergroup Limestone. The recumbent fold observed on the slope is a very rare geological structure that has not been found in Korea, and has important academic value in exploring the formation process of the Paleozoic geological structures in the Gangwon region. In this study, discussed the geological value of the geological structure observed on the slope of the road, and studied the management method of rockfall problem slopes. The state of development of recumbent folds has conservation value in geological scarcity and specificity. Preservation management measures should be prepared through the protection of slopes and measures to reduce of rockfall risks as geoheritage with an important value in geology science and education. Furthermore, it is expected to be preserved and utilized as a geopark.

Exploring Pre-service Earth Science Teachers' Perceptions about Learning on Geological Field Trip (야외지질학습에 대한 예비 중등 지구과학 교사의 인식 탐색)

  • Choi, Yoon-Sung;Kim, Chan-Jong;Choe, Seung-Urn
    • Journal of the Korean earth science society
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    • v.39 no.3
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    • pp.291-302
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    • 2018
  • The purpose of this study is to investigate pre-service middle school earth science teachers' perceptions about the learning of geological field trip. The study sample consists of 39 undergraduate students at the university located in a metropolitan city. Additionally, 4 pre-service earth science teachers are semi-structure interviewed. The instrument of the study includes a 5-category perception about the learning of geological field trip, which consists of needs, educational values, educational experience, teaching methods, and training for learning. The results are as follows. First, participants are important to the need and educational values of learning about the geological field trip regardless of gender and grade level. Second, all participants have experienced geological field trip in college. They have more opportunities to experiment for field trip as they advance to higher grade. There is significant difference between lower and higher graders in terms of the goal of learning about geological field trip. It needs a new lesson model to teach geology between men and women regarding teaching methods category. In order to practice geological field trip in school, participants perceive that they need the knowledge of geological context, experiment of field trips, and how to teach geological field trip to students. This study suggests that pre-service earth science teachers' perceptions include how to teach and learn geological field trip during their college year.

Numerical Simulation of Supercritical $CO_2$ Flow in a Geological Storage Reservoir of Ocean (해양 지중저장층내 초임계 $CO_2$ 유동에 대한 전산모사)

  • Choi, Hang-Seok
    • Journal of Korean Society of Environmental Engineers
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    • v.33 no.4
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    • pp.251-257
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    • 2011
  • In the present study, a 3-dimensional (3D) numerical model was developed to mimic the micro porous structure of a geological $CO_2$ storage reservoir. Especially, 3D modeling technique assigning random pore size to a 3D micro porous structure was devised. Numerical method using CFD (computational fluid dynamics) was applied for the 3D micro porous structure to calculate supercritical $CO_2$ flow field. The three different configurations of 3D micro porous model were designed and their flow fields were calculated. For the physical conditions of $CO_2$ flow, temperature and pressure were set up equivalent to geological underground condition where $CO_2$ fluid was stored. From the results, the characteristics of the supercritical $CO_2$ flow fields were scrutinized and the influence of the micro pore configuration on the flow field was investigated. In particular, the pressure difference and consequent $CO_2$ permeability were calculated and compared with increasing $CO_2$ flow rate.

3 Dimensional Geo-Information at Munkyeong area (문경지역에서 3차원 지반특성 분석연구)

  • Lee, Byung-Joo;Hwang, Jae-Hong;Lee, Chang-Won
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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    • pp.423-427
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    • 2010
  • To develope SOC(social overhead capita) which constructs the railroad, highway etc., the geo-technical foundation have to be well understood for the safety works. In this paper, we selected Moonkyung area for the study area, which has various geological units and geological structure including the big thrust and fold. By this reason one of the geo-technical information is the engineering geology map. To make the map, lithology and soil distribution with drilling data are important elements. Three dimensional geo-infomation is established by fence diagram which is several geological cross sections and/or computer software 3D Geomodeller, EarthVision, GSI3D, Gocad.

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Geological Structures of the Taebaek-Hajang Area, Samcheog Coalfield, Korea (삼척탄전(三陟炭田) 태백(太白)-하장지역(下長地域)의 지질구조(地質構造))

  • Kim, Jeong Hwan;Kim, Young Seok
    • Economic and Environmental Geology
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    • v.24 no.1
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    • pp.27-41
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    • 1991
  • Taebaeg-Hajang area, in the northern part of Taebaeg city, comprises of Paleozoic sedimentary sequences and Cretaceous intrusive and volcanoclastic rocks. The rocks in the area are affected by folding and thrusting during the Bulgugsa Orogeny. In Taebaeg area, geologic structures related with thrust movement are dominant. These structures are small scale of klippe and window, back thrust, and asymmetric folds related with blind thrust. Tear fault or compartment fault due to differential movement of thrust sheets have "en echelon" arrays. Small scale transpression effects occurred along these faults and produced the flower structure. According to strain measurement using by ooids from limestone and quartz grains from quartzite, strain ratios are very low and strain ellipsoids are apparent oblate type.

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Analysis of Slope Stability by Using Remote Sensing and GIS in Ichon Basin (원격탐사와 지구정보시스템 (GIS)을 이용한 이천분지의 사면안정평가)

  • Won, Jong Suck;Lee, Young-Hoon
    • Economic and Environmental Geology
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    • v.30 no.3
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    • pp.241-248
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    • 1997
  • In this study, Ichon basin is selected as study area and regional analysis of geological structure are done by using lineament analysis. The factors which affects slope stability, are chosen, and integrated to database using GIS (Geoscientific Information System). Landsat TM band 4, 5 and 7 are choosen and processed by various image enhancement technique to analyse the regional geological lineaments. Spatial distribution of lineament is analysed through lineament density map and study area can be divided the eight structural domains. Considering environmental geological characteristics of study area, rating and weighting of each factors for slope stability analysis are determined and spatial analysis of regional slope stability is examined through overlaying technique of GIS. The result of areal distribution of slope stability shows that the most unstable area is all over Mt. Buksung, Mt. Daepo, Mt. Songrim and Mt. Yankak.

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Electrochemical corrosion behavior of atmospheric-plasma-sprayed copper as a coating material for deep geological disposal canisters

  • Sung-Wook Kim;Gha-Young Kim;Young-Ho Lee;Jun-Hyuk Jang;Chung-Won Lee;Jeong-Hyun Woo;Seok Yoon
    • Nuclear Engineering and Technology
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    • v.55 no.11
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    • pp.4032-4038
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    • 2023
  • Cu, which exhibits excellent corrosion resistance in underground environments, has been investigated as a canister material for use in the deep geological disposal of spent nuclear fuels. In this study, the technical viability of atmospheric plasma spraying for producing Cu-coated canisters was investigated. A high-purity Cu film (millimeter scale) was deposited onto a stainless-steel substrate using a plasma gun with a shroud structure. Potentiodynamic polarization studies revealed that the Cu film exhibited a sufficiently low corrosion rate in the groundwater electrolyte. In addition, no pitting corrosion was observed on the Cu film surface after accelerated corrosion studies. A prototype cylindrical Cu film was fabricated on a 1/20 scale on a stainless-steel tube to demonstrate the scalability of atmospheric plasma spraying in producing Cu-coated canisters.

Suggestion of Regression Equations for Estimating RMR Factor Rating by Geological Condition (지질 조건을 고려한 RMR 인자값 추정을 위한 선형회귀식 제안)

  • Kim, Kwang-Yeom;Yim, Sung-Bin;Kim, Sung-Kwon;Kim, Chang-Yong;Seo, Yong-Seok
    • The Journal of Engineering Geology
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    • v.17 no.4
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    • pp.555-566
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    • 2007
  • In general, RMR classification system is used for the support design of a tunnel. Face mapping during excavation and RMR-based rock classifications are conducted in order to provide information for complementary changes to preliminary survey plans and for continuous geological estimations in direction of tunnel route. Although they are ever so important, there are not enough time for survey in general and sometimes even face mapping is not available. Linear regression analysis for the estimation of mediating RQD and condition of discontinuities, which require longer time and more detailed observation in RMR, was performed and optimum regression equations are suggest as the result. The geological data collected from tunnels were analyzed in accordance with three rock types as sedimentary rock, phyllite and granite to see geological effects, generally not been considered in previous researches. Parameters for the regression analysis were set another RMR factor.

A Case Study on the Design of Tunnel Excavation in Geological Anomalies (터널굴착시 지질이상대 통과방안 설계사례 연구)

  • Yoo, Joung-Hoon;Kim, Yang-Kyun;Chung, Chul-Hwa
    • Tunnel and Underground Space
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    • v.21 no.5
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    • pp.341-348
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    • 2011
  • As a result of the detailed site investigation performed for the design of a 4.3 km long tunnel, geological anomalies of four fault zones and a rock boundary were discovered on the tunnel route. Most of all, it was confirmed that pyrite, which may corrode steel material, is contained inside the geological anomalies, and pressured ground water flows out of the fault fractured zone. To overcome these geological conditions, antisulfur concrete for the concrete lining and anticorrosive swelling rock bolts are designed in the pyrite-containing sections. For the sections where a great amount of groundwater outflows, water blocking methods including grouting are applied according to the result of numerical analyses on the seepage. In addition, since the past earthquakes occurred around Korea have take place mainly near fault zones, seismic analyses were performed based on the Soil-Structure Interaction (SSI) concept and the strength of concrete tunnel lining is designed to be 27 MPa from 24 MPa in order to reinforce the tunnel structure.