• Title/Summary/Keyword: 풍화층

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SEM-EDS를 이용한 고대문화의 해석 - 고대의 유리구슬 -

  • Kim, Gyu-Ho;Heo, U-Yeong
    • 한국전자현미경학회:학술대회논문집
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    • 1999.05a
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    • pp.40-44
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    • 1999
  • 기록이 없는 과거 역사에 대한 연구는 문화재라는 간접적인 자료를 통하여 이루어지고 있다. 지금까지의 문화재 연구는 외형적인 특성을 연구하는 고고학이나 미술사의 분야만으로 국한하였으나 점차 내형적인 특성을 연구하는 과학적인 분석기술도 다양하게 응용되고 있다. 문화재의 특성적 성분을 분석하여 원료, 제작방법, 시대, 그리고 지역으로 그룹화한다면 문화재의 특성과 함께 지역, 시대에 따른 문화적 형태와 수준, 그리고 문화의 유입 경로 등에 대한 자료를 제시할 수 있다. 분 연구에서는 유리나 도자기 유약 등의 문화재를 분석할 경우에 대한 SEM-EDS의 정량분석 조건들을 설정하고 경남 김해 양동리고분에서 출토된 고대 유리구슬에 대하여 직접 적용하여 보았다. 분석 결과, 매장되었던 고대 유리에서는 풍화층이 존재하며 이에 대한 분석조건과 정량분석의 문제점들을 고찰하였다. 이를 기초로 하여 적용한 양동리고분의 유리구슬은 알칼리계 유리로 칼리계 유리는 AD 1C, 소다계 유리는 AD 2C말$\sim$3C초부터 나타난 것으로 추정된다. 그리고 유리의 색상은 전이금속 동(Cu), 철(Fe), 그리고 망간(Mn)의 함유량과 밀접한 관계가 있음을 보인다. 이 분석 결과에 따라 고대 유리구슬의 성분 함유량이 원료, 색상, 유구편년, 그리고 지역에 따라 그룹이 형성될 수 있음을 확인하였다.

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The Characteristic and genesis of Polysequum Soils in Jeju (Polysequum토양(土壤)의 특성(特性) 및 생성(生成)에 관(關)한 연구(硏究))

  • Shin, Jae-Sung;Jung, Pil-Gyun;Um, Ki-Tae
    • Korean Journal of Soil Science and Fertilizer
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    • v.9 no.2
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    • pp.93-98
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    • 1976
  • The present paper is a part of a study aimed at gaining information on the origin, mode of deposition, and characteristics of volcanic soils in Jeju. Volcanic activity of Jeju island has extremely influenced on the formation of various soils. Polysequum phenomenon of soils is one of outstanding soil genesis in Jeju. The typical polysequum soils was collected and analyzed by morphological, physico-chemical, mineralogical and micromorphological approaches The results are as follows: 1. The soils consists of polysequa, A and B horizons from volcanic ashes, unconsolidated volcanic sand layer and B(I) horizons from residual basalts. 2. The lithological discontinuity is also very distinct; silt loam from volcanic ashes, sand (II) from volcanic sand and clayey (III) from basalts. 3. Volcanic sand layer seems to be influenced by lava flow. The properties of it are similar to volcanic ashes rather than beneath residuum in micromorphological aspects. In micromorphological, this layer is gradually changed into soils. 4. Dominant clay minerals are allophane in A and B horizons from volcanic ashes and kaoline, vermiculite and illite from residual basalts. 5. The soils are not developed. There is no formation of argillic horizon in subsurface layers.

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Estimation of Shear Wave Velocity of Weathered Granite Layer Using Nonlinear Multiple Regression Analysis; A Case Study in South Korea (비선형 다중회귀분석을 통한 국내 화강 풍화대 전단파 속도 평가에 대한 사례 연구)

  • Lee, Seung-Hwan;Baek, Sung-Ha;Chung, Choong-Ki;Kwak, Tae-Young
    • Journal of the Korean Geotechnical Society
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    • v.37 no.6
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    • pp.29-37
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    • 2021
  • Since many geotechnical structures are constructed on a weathered granite layer, it is important to evaluate their characteristics. As a seismic design is the more important nowadays, the demands to estimate a shear wave velocity (VS) based on acceptable methods are increasing. In this study, an empirical equation predicting VS of the weathered granite layer is suggested based on the nonlinear multiple variable regression analysis whose independent variables are both SPT (Standard penetration test)-N60 and chemical weathering index. It is concluded that the accuracy of the empirical equation estimating VS of the weathered granite layer increases when it considers the chemical weathering index as an additional independent variable compared to the result of simple regression analysis using only N60.

공주 공산성 원형연못의 지반에 대한 탄성파 굴절법 탐사

  • 변성환;오진용;서만철
    • 한국지구물리탐사학회:학술대회논문집
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    • 2004.06a
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    • pp.132-138
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    • 2004
  • 탄성파 탐사는 인공지진파를 이용하여 지표면 하부의 물성을 알아내는 지구물리탐사로서 20 세기 초부터 석유탐사와 공학적 지반조사에 가장 널리 사용되었다. 굴절법 탄성파 탐사는 지층의 탄성파 속도를 알아내는 방법으로서 최근에는 석조문화재 등의 지반특성 조사에서 사용된 예가 있다. 이번 연구에서는 공주 공산성의 쌍수정 광장에 위치하는 공산성 원형연못 주변의 지반에 대하여 굴절법 탐사를 실시하였다. 쌍수정 광장은 기존의 발굴조사를 통하여 백제 추정왕궁지가 위치한 곳으로 알려졌으며, 광장 남쪽에 원형연못(상면직경 7.3 m, 바닥직경 4.78 m, 높이 3 m)도 발굴되었다. 원형연못 주변에 5개 탄성파 측선을 설치하였고, 해머 타격점과 수신기의 배열을 3가지 다른 방식을 적용하여 24 m, 31 m, 48 m 측선깊이의 굴절법 자료를 얻었다. 대체로 공산성 원형연못 주변의 지반은 3개 층으로 구성되어 있다. 각 층의 겉보기 속도는 약 261${\~}$391 m/s, 약 591${\~}$992 m/s, 약 1950${\~}$3230 m/s이며, 첫 번째와 두 번째 층의 두께는 각각 약 2${\~}$2.4 m 와 4.6${\~}$8.6 m이다. 일반적으로 최하부 층의 속도는 기반암, 상부층들의 속도는 풍화토에 대응한다. 그러나 두 번째 층의 주시곡선 형태와 속도범위는 국내 석탑 문화재 하부의 것과 유사한 것으로 보아 공산성 연못주변은 인공적인 기초지반의 가능성을 제기하며, 그렇다면 공산성 원형연못은 파내려 간 것보다는 쌓아 올렸을 것이다.

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Earthquake Engineering Bedrock Based on the Shear Wave Velocities of Rock Strata in Korea (국내 암반지층의 전단파속도에 근거한 지진공학적 기반암 결정)

  • Sun, Chang-Guk
    • The Journal of Engineering Geology
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    • v.24 no.2
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    • pp.273-281
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    • 2014
  • In most current seismic design codes, design earthquake ground motions are defined by a reference spectrum, based on bedrock and site amplification factors that quantify the geotechnical dynamic conditions. Earthquake engineering bedrock is the fundamental geotechnical formation where the seismic waves are attenuated without amplification. To better define bedrock in an earthquake engineering context, shear wave velocity ($V_S$ ) data obtained from in-situ seismic tests were examined for several rock strata in Korea; these data were categorized by borehole drilling investigations. The $V_S$ values for most soft rock data in Korea are > 750 m/s, which is the threshold $V_S$ value for identifying engineering bedrock from a strong motion station. Conversely, VS values are < 750 m/s for 60% of $V_S$ data in weathered rock in Korea. Thus, the soft (or harder) rock strata below the weathered rock layer in Korea can be regarded as earthquake engineering bedrock.

Slope Stability Analysis and Suggestion of Stabilization Methods on Failed Cut-Slopes Interbedded with Weakness Layer (연약층이 협재된 절개면의 안정성 해석 및 대책)

  • 구호본;이대영;김학준
    • The Journal of Engineering Geology
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    • v.13 no.2
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    • pp.157-170
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    • 2003
  • This study is performed to investigate the cause of slope failure and to suggest suitable stabilization methods for the failed rock slopes. The slope which is located along the national highway between Maesan and Kakok in Dangjin-gun failed during the construction of roads. Site investigation, drilling program, field measurements, rainfall records, and stability analyses are used to investigate the cause of the slope failure. The problem determining the cut-slope angle based on the existing design manual for the construction of roads is reviewed based on the case history given in this paper. If weakness layer and geological structures such as folds and faults are developed in a slope, slope failure is possible even though the direction of slope and the direction of discontinuities depart more than $30^{\circ}$.

Present Deterioration Situation and Study on the Conservation Treatment of the Seven-story Stone Pagoda of Jeongamsa Temple (정선 정암사 수마노탑의 손상현황과 보존처리연구)

  • Hwang, Jeong Eun;Kim, Sa-Dug;Jung, Hee Soo
    • 보존과학연구
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    • s.34
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    • pp.110-122
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    • 2013
  • The Seven-story Stone Pagoda of Jeongamsa Temple consists of dolomitic limestone. The surface of the stone stupa is efflorescene. There are spaces between parts in the stereobate and part of roof at the fifth story and above. The space between parts is colonized by biological contaminants. There are breakaway parts in the third, fifth, sixth, seventh story. The dry and wet cleaning of all the biological contaminants, efflorescene. The steam cleaning of rest of efflorescene. The use of poultice with oxalic acid, were done to remove the rust. Breakaway parts are inosculated by L30 and Por-rok. Spaces between parts are waterproofing by Porrok. After treatment, the efflorescene of part of waterproofing are comparatively scarce. So waterproofing is effective at reduced efflorescene and waterproof.

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Sedimentary Characteristics and Chronology of Loess-paleosol Sequence in Jeongjang-ri, Geochang basin, Gyeongnam Province (경남 거창분지 정창리 뢰스-고토양 연속층의 퇴적물 특성과 편년)

  • Hwang, Sang-Ill;Kang, Chang-Hyeok;Yoon, Soon-Ock
    • Journal of the Korean Geographical Society
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    • v.46 no.1
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    • pp.1-19
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    • 2011
  • The physical and chemical characteristics of loess-paleosol sequence in Jeongjang-ri, Geochang basin are examined using the magnetic susceptibility measurement, grain size analysis, OSL age dating, major, rare earth and trace elements analysis. The grain size characteristics of the loess-palesol sequence are obviously different from those of river sediment forming river terrace deposits and the Chinese Loess Plateau. The loess-paleosol sequence consisting of L1, L1LL1, L1S1, L1L2, S1 and L2 from top to bottom is estimated to MIS 2~MIS 6 and the river terrace to MIS 7. The compositions of major, rare earth and trace elements indicate that the sequence show more weathered characteristics than the Chinese Loess Plateau and originated from the Chinese Loess Plateau. These features are in harmony with the previous studies in Korea.

A Study on the Design Procedure of Mega Foundations for a High-rise Building Using Bi-Directional High Pressure Pile Load Test (BDH PLT) (양방향 고유압 말뚝재하시험(BDH PLT)을 이용한 초고층 건축물의 대구경 현장타설말뚝 설계절차에 관한 연구)

  • Kim, Sung-Ho;Choi, Yongkyu
    • Journal of the Korean GEO-environmental Society
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    • v.10 no.3
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    • pp.29-36
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    • 2009
  • In this paper, a case of a high-rise building supported by a large-diameter drilled shaft socketed in a weathered ground has been studied. The design case of pile foundation presented in this paper could be a representative example of execution of pile design through three(3) design stages of "preliminary design-proof test-supplementary design". As proof test, two(2) BDH PLT (Bi-directional High Pressure Pile Load Test) were performed at the early construction stage. By following the design process of this way, the economic pile design could be carried out and a large amount of construction cost saving could be realized.

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The Irrigation and Drainage Systems of Coastal Alluvial Plain: Sand Dune Area and Allurial Plain in Bulgap River Catchment in South Jeolla Province (소규모 임해충적평야의 수리체계 -불갑천 하류의 충적지와 해안사구를 중심으로-)

  • Kahng Taygyoon
    • Journal of the Korean Geographical Society
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    • v.39 no.6 s.105
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    • pp.863-872
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    • 2004
  • The coastal alluvial plain, sand dune, tidal nat might be the most prominent coastal landscape in western coast of Korea. The purpose of this paper is to examine the irrigation and drainage systems of the alluvial plain in the tidal coast. This study is concerned on the geomorphological and cultural landscapes of the alluvial plain in the western coast of the South Jeolla Province. The alluvial deposits have developed mainly by the actions of tidal currents, rather than transporting sediments by stream. The transformation of plain has been affected by human agency since 1920's. Dwellers have constructed the reservoir, banks, dammed pools, lock gates, and tide-dykes for the reclamation, irrigation, and drainage on the alluvial plain, coastal sanddune, and tidal flats.