• Title/Summary/Keyword: geologic structures

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A Study on the Electrical Resistivity Prospecting for Geologic Model Strata (지층모형(地層模型)에 의(依)한 전기비저항(電氣比抵抗) 탐사법(探査法) 연구(硏究))

  • Min, Kyung Duck;Lee, Young Hoon
    • Economic and Environmental Geology
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    • v.12 no.1
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    • pp.1-12
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    • 1979
  • A model study was conducted for the interpretation of simple geologic structures. Experiments were carried out for the cases of two horizontal beds and dipping beds in a water tank by using Wenner and Schlumberger arrays respectively. As a geologic stratum of experimental model, cement be (cement: sand=1:2) of $70cm{\times}60cm{\times}10cm$ was used. It was found out from a preliminary experiment that a measuring sounding of Wenner arrays is one third of the distance between two current electrodes, and Schlumberger arrays is one fourth of the distance which is a half of the value determined by usual method of calculation. Equi-resistivity curves were obtained for the cases of horizontal beds and dipping beds, and mapped on the longitudinal and cross sections of the water tank. These curves delineate the shape and degree of dip of bed to some extent. The calculation of depth to beds by using a master curve is somewhat complicated and inexact. In this study, new method for this calculation using a ${\rho}_a/{\rho}_1-a$ graph was proposed, and turned out that this method is simpler and exact.

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ANALYSIS OF THE CHARACTERISTICS ABOUT GYEONG-GANG FAULT ZONE THROUGH REMOTE SENSING TECHNIQUES

  • Hwang, Jin-Kyong;Choi, Jong-Kuk;Won, Joong-Sun
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.196-199
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    • 2008
  • Lineament is defined generally as a linear feature or pattern on interpretation of a satellite image and indicates the geological structures such as faults and fractures. For this reason, a lineament extraction and analysis using remote sensing images have been widely used for mapping large areas. The Gyeong-gang Fault is a NNE trending structure located in Gangwon-do and Kyeonggi-do district. However, a few geological researches on that fault have been carried out and its trace or continuity is ambiguous. In this study, we investigate the geologic features at Gyeong-gang Fault Zone using LANDSAT ETM+ satellite image and SRTM digital elevation model. In order to extract the characteristics of geologic features effectively, we transform the LANDSAT ETM+ image using Principal Component Analysis (PCA) and create a shade relief from SRTM data with various illumination angles. The results show that it is possible to identify the dimensions and orientations of the geologic features at Gyeong-gang Fault Zone using remote sensing data. An aerial photograph interpretation and a field work will be future tasks for more accurate analysis in this area.

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Shallow Geological Structure of the Yongil Bay, Southeast Coast of Korea (한국 남동부 영일만의 천부 지질구조)

  • Choi Dong-Lim;Kim Seong-Ryul;Suk Bong-Chool;Oh Jae-Kyung
    • The Korean Journal of Petroleum Geology
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    • v.1 no.1 s.1
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    • pp.53-62
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    • 1993
  • The geologic structure of the Yongil Bay was studied in detail based on high resolution seismic profiles. The seafloor trends NE to SW with a deeper part off the Kuryong Peninsula. The seafloor is rather smooth due to the Quaternary fluvial deposits in the lower part and muddy sediments in the upper part. The seafloor off Umockri is very irregular due to erosion where Tertiary sedimentary rocks crop out. The underlying basement rocks were strongly deformed with faults and folds. High-angled reverse faults mostly trend N-S and NNW-SSE and are indicative of westward thrusting. Normal faults in NW-SE and WNW-ESE directions occur locally. Large folding structures trend NE-SW nearshore area of Umockri. The geologic structure suggests that the bay was subject to compressional stress regimes trending E-W and/or NW-SE prior to the early Late Miocene.

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A Case Study for the Support Pattern Appropriateness in Rock Tunneling Designs (지하철 설계시의 지보형식 적정성에 관한 연구)

  • 김수정;장태우
    • The Journal of Engineering Geology
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    • v.5 no.2
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    • pp.167-179
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    • 1995
  • The only three elements such as RQD, N -value and Es were used as a quantitative standard for the design of supporr pattern determidetion on subway line 8th in Seoul. Because the support pattern that was obtained by these elements could not he determined on the basis of the quantitative of geology and the orientations and properties of discontinuity planes, there have been some problems in determining the economic support pattern and tunnel stability. Therefore, in an attempt to determine the stable and economic support pattern with more quantitative elements, more flerrible rock mass classification with geologic conditions was performed by using RMR at 1745 sections and Q-system at 374 sections within Seongnam block on subway line 8th. Then, rusults by these two methods were compared with standard support pattern of the subway line 8th. Moreover, relationships between geology, geologic structures and topography to rock mass grades were studied. According to the rusult of this study, it is judged that the standard support pattern designed with PD-4 or PS - 4 should have been subdivided into 4~6 support patterns. Some sections where geologic structures such as faults and joints are developed tend to have rock mass grades. And they also have low rock mass grades near valley. On thr other hand, they show intermediate grades at piedmont area and the greatest ones at high mountains.

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Geologic Structure and Rocks as Geotechnical Risk Factors at Intermediate depth Tunneling in Korea (한국의 대심도 터널 지반 위험인자로서 암석과 지질구조)

  • Ihm, Myeong Hyeok
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.3
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    • pp.551-557
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    • 2022
  • Geotechnical risk factors encountered in intermediate-depth underground tunnel construction are diverse, and the types and standards of risk factors are different according to the depth and regional geological characteristics of Korea. In order to understand the effects of geological characteristics and geologic structure on safety, which show various porous characteristics of urban underground complex ground, the risk factors of intermediate-depth rock mass in Korea were analyzed based on domestic and foreign cases. As a result of the study, seven categories affecting the stability of the intermediate-depth tunneling, namely, geologic structure, rock characteristics, hydrogeology, overburden, high stress, ground characteristics and artificial structures, and about 22 risk factors were derived. We present the risk criteria and interval values for risk evaluation of faults, folds, dikes, and rocks that have the greatest influence among risk factors. Criteria and interval values for other risk factors are under study.

The virtual penetration laboratory: new developments for projectile penetration in concrete

  • Adley, Mark D.;Frank, Andreas O.;Danielson, Kent T.;Akers, Stephen A.;O'Daniel, James L.
    • Computers and Concrete
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    • v.7 no.2
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    • pp.87-102
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    • 2010
  • This paper discusses new capabilities developed for the Virtual Penetration Laboratory (VPL) software package to address the challenges of determining Penetration Resistance (PR) equations for concrete materials. Specifically, the paper introduces a three-invariant concrete constitutive model recently developed by the authors. The Advanced Fundamental Concrete (AFC) model was developed to provide a fast-running predictive model to simulate the behavior of concrete and other high-strength geologic materials. The Continuous Evolutionary Algorithms (CEA) automatic fitting algorithms used to fit the new model are discussed, and then examples are presented to demonstrate the effectiveness of the new AFC model. Finally, the AFC model in conjunction with the VPL software package is used to develop a PR equation for a concrete material.

Analysis on the Argumentation Pattern and Level of Students' Mental Models in Modeling-based Learning about Geologic Structures (지질구조에 대한 모델링기반 학습에서 나타나는 논증패턴과 정신모형 수준에 대한 분석)

  • Park, Su-Kyeong
    • Journal of The Korean Association For Science Education
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    • v.35 no.5
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    • pp.919-929
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    • 2015
  • This study aims to develop a modeling-based learning program about geologic structures and to reveal the relationship between the argumentation patterns and levels of students' mental models. Participants included 126 second grade high school students in four sessions of modeling-based learning regarding continental drift, oceanic ridges, transform faults, and characteristics of faults. A modeling-based learning program was implemented in two classes of the experimental group, and teacher-centered traditional classes were carried out for the other students in the comparison group. Science achievement scores and the distribution of students' mental models in experimental and comparison groups were quantitatively compared. The video-taped transcripts of five teams' argumentation were qualitatively analyzed based on the analytic framework developed in the study. The analytic framework for coding students' argumentation in the modeling-based learning was composed of five components of TAP and the corresponding components containing alternative concepts. The results suggest that the frequencies of causal two-dimensional model and cubic model were high in the experimental group, while the frequencies of simple two-dimensional model and simple cross sectional model were high in the comparison group. The higher the frequency of claims, an argumentation pattern was proven successful, and the level of mental model was higher. After the rebuttal was suggested, students observed the model again and claimed again according to new data. Therefore, the model could be confirmed as having a positive impact on students' argumentation process.

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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Geological Structures of Yeongweol - Yemi Area, Kangweon-do, Korea (강원도(江原道) 영월(寧越) - 예미지역(禮美地域)의 지질구조(地質構造))

  • Kim, Jeong Hwan;Koh, Hee Jae;Lee, Jong Dae
    • Economic and Environmental Geology
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    • v.24 no.2
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    • pp.167-176
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    • 1991
  • The Yeongweol - Yemi area, in the area between the Kagdong thrust fault and Samcheog Coalfield, comprises Paleozoic and Mesozoic sedimentary and igneous rocks. Geologic structures related with thrust movements are dominant in the area. These are thrust faults, imbricate structures and hanging-wall anticline. Thrust sheets were transported from NW to SE and these differ from the Cretaceous Bulkuksa Orogeny of which thrust sheets were transported from N to S. NE - trending folds are dominant, but NW - trending folds and refolded folds are also found. NW - trending folds are only found in the Cambro-Ordovician sedimentary rocks. It might be an indication of the presence of late Paleozoic tectonism in the Korean Peninsula.

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Orientations of Tecto-lineaments and Discontinuities for Different Rock Types in Andong Area (안동지역의 암종별 선구조선과 불연속면의 방위특성)

  • Kim Gyo-Won;Ihm Myeong-Hyeok
    • The Journal of Engineering Geology
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    • v.16 no.1 s.47
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    • pp.23-30
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    • 2006
  • This study was carried out to understand the relationship between orientation of tecto-lineaments obtained from aero-photograph and orientation of discontinuities measured at field for the rock types of igneous, sedimentary and metamorphic rocks in Andong area. Total 847 tecto-lineaments were extracted from the aero-photographs and total 1,940 discontinuities including joints, foliations and faults were measured during geologic survey. By using the software DIPS, preferred trends of tecto-lineaments were deduced as N30E-N40E for igneous rocks and N50E-N60E for both sedimentary and metamorphic rocks, while the trends of discontinuities were found as N40E-N50E for igneous rocks, N50E-N80E for sedimentary rocks and N50E-N60E for meta morphic rocks. Even though both orientations for a given rock type showed relatively good agreement in its trend, some discrepancy is also appeared. Since construction safety of geo-structures such as tunnel and slope, etc., is significantly affected by the orientation of discontinuities in rock masses, it is highly recommended to perform a detailed geologic survey as well as an aero-photograph interpretation at a design stage.