• Title/Summary/Keyword: 화산쇄설물

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A Study on Strength Characteristics of Jeju-island's Scoria(Song-E) (제주도 화산쇄설물(송이)의 강도특성에 관한 연구)

  • Nam, Jung-Man;Ko, Ho-Seong;Oh, Dong-Il
    • International Journal of Highway Engineering
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    • v.5 no.4 s.18
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    • pp.37-47
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    • 2003
  • Song-E(scoria) is civil material that we frequently meet with in road building in Jeju-island. It is known that Song-E is the material of high crush and large particle. But, the study on the scoria is not enough, so there are many difficult in handling method. In this study, We research basic strength characteristics on Song-E gathered at various part in Jeju-island. Results of this study(strength characteristics of Song-E) are applied to design of road, breast wall and slope as basic data.

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Review about the Impacts from Volcanic Ash Fall (화산재 강하로부터의 영향 고찰)

  • Lee, Jeonghyun;Yun, Sung-Hyo
    • Korean Journal of Mineralogy and Petrology
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    • v.33 no.1
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    • pp.73-86
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    • 2020
  • The materials generating from volcanic eruption are volcanic gases, lavas and pyroclastic materials. Volcanic ash which has small-grain size (< 2 mm in diameter) can be moved easily and disperse widely, thus it may affect to communities across hundreds of square kilometers. The impacts from volcanic ash fall on people, structures, equipments, plants and livestock largely depend on ash thickness. According to increasing ash thickness, the intensity and area of damage may increase and affect significant damages not to human health but also to infrastructures. To reduce the impacts from volcanic ash fall, we have to establish the guidances about the nature and extent of the hazard and prepare the actions to increase abilities of communities to manage hazard. Although we don't have any experience caused by volcanic ash fall during and after volcanic eruption, we need to prepare the impacts of volcanic ash fall for future eruption in the areas surrounding Korea.

A Layered Felsic Diatreme near Weolseong, Kyeongsang Nam Do, Korea (층상형(層狀型)의 규장암질(珪長岩質) DIATREME)

  • Park, Ki-Hwa;Kim, Seon-Eok
    • Economic and Environmental Geology
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    • v.18 no.4
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    • pp.357-368
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    • 1985
  • The Weolseong diatreme crops out about 28km south of Kyeongju City, Korea. The diatreme is a circular shaped volcanic vent, 1.2km in diameter, that formed subaerially, probably by phreatomagmatic (phreatoplinian) eruptions of Tertiary age. The rocks occupying the display well developed layering produced by base surge and proximal ba11istic fall. Accretionary lapilli are a common component. The rocks comprise tuff breccia and fine-grained rock derived from the vent walls. This sequence has undergone subsidence of at least over 650m. Most explanations for the presence of bedded tuffs at considerable depths within a volcanic pipe involve subsidence. Comparable amount of subsidence are recorded in many diatremes in other parts of the world. The ore body is distinctly circular and funnel shaped in center of diatreme. The vent area of diatreme served as channel ways for the mineralized hydrothermal fluids.

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Neaushore sedimentary environments of the Sinyangri Fornation in Cheju Island, Korea (제주도 신양리층의 연안퇴적환경)

  • 한상준;윤호일
    • 한국해양학회지
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    • v.22 no.1
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    • pp.1-8
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    • 1987
  • The Sinyangri Formation crops out in the vicinity of the Seongsan Peninsula, Cheju Island. Based on sedimentary structures, texture and composition, the lithologic sequence has been classified, in ascending stratigraphic order, into three lithofacies: parallel laminated sandstone facies (Facies I): conglomerate facies(Facies Il); and cross stratified sandstone facies (F acies Ill). Wedge-to-parallel, seaward-inclined in low angle less than 10$^{\circ}$lamina -sets with alternations of coarseand fine-grained sediments in the Facies I are the characteristic sedimentary structures in the foreshore depositional environment. Grains of this faciesare well sorted with good roundness compared with the other two facies, partly showing inverse graded bedding. Facies II,largely composed of claset-supported,very poorly-sorted conglomerates,does not pinch out but occurs continuously along the Sinyangri beach.Interstitial spaces between the clasts are mostly infilled with volcanic-ash and small amounts of well-rounded shell fragments.Maximum bed thickness as well as the size of imbedded basaltic clasts decreases to the south(toward Sinyangri). Large clasts with parallel lamination originated from the underlying Facies i,are generally elongated parallel to the bedding plane and display no systematic horizontal variations in size indicative of in-situ clasts.In view of the facts above it seems that large gravels from the basaltic rocks are transgressive lag conglomerates which are partly affected by the combination of longshore currents and propagating wave.Local occurrence of cross-strata dipping toward the south in the upper part of Facies IIreinforces the evidence of the action of longshore currents. Facies IIIis characterized by bidirectional trough cross-starifiction and wave ripples associated with the upper shoreface(surfzone) environments.In summary,the Sinyangri Formation represents the depositional environments of foreshore to upper shoreface truncated by disconformity between Facies Iand II.

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Numerical Analysis of Offshore Wind Turbine Foundation Considering Properties of Soft layer in Jeju (제주 연약지층 특성을 고려한 해상풍력기초의 수치해석적 연구)

  • Yang, Ki-Ho;Seo, Sang-Duk;Cho, Yee-Sun;Park, Jeong-Jun
    • Journal of the Korean Geosynthetics Society
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    • v.12 no.4
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    • pp.45-56
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    • 2013
  • Recently, offshore wind farms are increasingly expected, because there are huge resource and large site in offshore. Jeju island has optimum condition for constructing a wind energy farm. Unlike the mainland, Jeju island has stratified structure distribution between rock layers sediments due to volcanic activation. In these case, it can be occur engineering problems in whole structures as well as the safety of foundation as the thickness and distribution of sediment under top rock layer can not support sufficiently the structure. In this paper, the settlement and stress distribution is predicted by numerical analysis when the mono-pile base are constructed on various soft layer between stratified structure. To determine the settlement of the pile foundation supported on stratified rock layer, the geological investigation at the 3 regiions and the results of laboratory experiments of the stratified rock layer is required.

Studies on the Leaching and absorption characteristics of the nutrient element in Cheju Scoria (제주 송이배지의 양분 탈흡착 특성에 관한 연구)

  • 이신찬;김양록;양상호;황재종;강호준;허태현;현승원;정순경
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 1997.11a
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    • pp.57-60
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    • 1997
  • 양액재배용 고형배지로서 Rockwool 이나 Perlite둥이 사용되고 있다. 이는 농가 경제적 부담이 클 뿐만 아니라, 사용후 폐기시에도 환경보존의 문제점이 있다. 양액재배용 고형배지로 활용할 경우 공극이 많아 가볍고 수분 보유량과 통기성이 좋은 이점도 있으나 화산쇄설물의 일종으로 양분을 흡착하거나 송이가 함유하고 있는 성분들을 방출하는 특성이 있는 것으로 예상되나 확실한 조사가 되어있지 않다. (중략)

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감포와 연일 지역 벤토나이트 내 일라이트-스멕타이트 혼합층광물의 팽창성 및 X-선 부합성산란영역크기에 관한 연구

  • 강일모;문희수;유장한
    • Proceedings of the KSEEG Conference
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    • 2003.04a
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    • pp.325-329
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    • 2003
  • 일반적으로 스멕타이트는 온도, 시간, 공극수 내 K 함량 등이 증가하면서 일라이트화 작용을 통하여 일라이트-스멕타이트 혼합층광물(I-S)로 전이된다. 따라서, 벤토나이트(주로 스멕타이트질 광물로 구성된 화산쇄설물의 변질산물)는 지질환경에 따라 스멕타이트 또는 다양한 혼합층비를 갖는 I-S를 함유하게 된다. 이러한 벤토나이트 내 스멕타이트와 일라이트의 혼합층비는 팽창성(expandability)으로 정량화할 수 있다. (중략)

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