• Title/Summary/Keyword: 기초 하부

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Digital Library 구축 기술동향

  • 김성혁
    • Proceedings of the Korea Database Society Conference
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    • 1998.09a
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    • pp.51-80
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    • 1998
  • 6. 결론[1] 6.1. 국내 현황 ㆍ DL 관련 기술에 대한 기초연구 및 응용개발이 독자적이고 소규모로 추진 중 ㆍ 많은 기관이 이미지 기반으로 원문 구축 ㆍ 표준화 없이 정보 구축 ㆍ기관 및 시스템간 상호 운용성 보장 없음 $.$정보 인프라 미비 6. 결론[2] 6.2. 앞으로 DL 연구/개발 방향 $.$DL:지식정보화 사회의 기반구조 $.$국가 주도하의 DL 연구/개발 - 장기간의 기초 연구와 응용 연구 -국가적 표준차 요구 -정보 하부 구조 구축 $.$정보통신 기업의 DL 연구 및 개발 참여 유도 -관련기업, 출판사, 도서관, 저작권 협회의 적극적 참여-정보 구축/서비스 관련 기술 개발 -정보 경제학 도입(중략)

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A Case Study on Ground improvement of a Retaining Wall Foundation by Using High Pressure Grouting (고압분사공법을 이용한 옹벽기초지반 보강 사례)

  • Park, Jong-Ho;Jang, Sun-Cheul;Park, Chang-Hun;Yoon, Hee-Kyung
    • 기술발표회
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    • s.2006
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    • pp.199-209
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    • 2006
  • 현재 연약지반의 개량 및 구조물기초 지반의 보강을 위하여 약액주입공법 및 고압분사주입공법 등의 주입공법이 널리 행해지고 있는 실정이다. 이에 본 연구에서는 00교 교대 전면 옹벽기초 하부지반을 고압분사주입공법을 이용해 보강한 사례로서 설계 및 시공, 시험 자료를 분석하고, 보강작업에 따른 지반의 개량효과를 분석하였다. 개량효과학인을 위한 시추조사와 시추공영상 촬영 이미지 관찰결과에서는 고압분사에 의해 양호한 상태의 고결체(토사 + 시멘트 페이스트)가 형성되었음을 확인 할 수 있었으며, 고결체와 원지반의 복합지반상에서 실시한 평판재하시험 결과 및 시추조사시 채취된 고결체 Core에 대해 실시한 일축압축강도시험 결과에서도 설계시 가정한 값을 모두 만족하는 것으로 나타나 연약지반의 강도가 개량되어 안정성을 확보한 것으로 확인되었다.

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Dynamic Characteristics of Liquidity Filling Materials Mixed with Reclaimed Ash (매립석탄회를 혼합한 유동성 충진재의 동적거동특성)

  • Chae, Deokho;Kim, Kyoungo;Shin, Hyunyoung;Cho, Wanjei
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.4
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    • pp.5-11
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    • 2014
  • Recently, there have been various lifeline installations constructed in the underground space of urban area due to the effective use of land. For newly installed lifelines or the management of the installed lifelines, many construction activities of excavation and backfilling are observed. Around these area, there are possibilities of collapse or excessive settlement due to the leaking of the pipe or unsatisfactory compaction of backfill material. Besides, construction costs can be saved since the on-site soils are used. The application of this liquidity filling material is not only to the lifeline installation but also to underpin the foundation under the vibrating machinery. On the evaluation of the applicability of this method to this circumstance, the strength should be investigated against the static load from the machine load as well as the vibration load from the activation of the machine. In this study, the applicability of the liquidity fill material on the foundation under the vibrating machinery is assessed via uniaxial compression and resonant column tests. The liquidity filling material consisting of the on-site soils with loess and kaolinite are tested to investigate the static and dynamic characteristics. Furthermore, the applicability of the reclaimed ash categorized as an industrial waste is evaluated for the recycle of the waste to the construction materials. The experimental results show that the shear modulus and 7 day uniaxial strength of the liquidity filling material mixed with reclaimed ash show higher than those with the on-site soils. However, the damping ratio does not show any tendency on the mixed materials.

Reliability Analysis of Offshore Wind Turbines Considering Soil-Pile Interaction and Scouring Effect (지반과 말뚝의 상호작용 및 세굴현상을 고려한 해상풍력터빈의 신뢰성 해석)

  • Yi, Jin-Hak;Kim, Sun-Bin;Yoon, Gil-Lim
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.28 no.4
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    • pp.222-231
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    • 2016
  • Multi-member lattice-type structures including jackets and tripods are being considered as good alternatives to monopile foundations for relatively deep water of 25-50 m of water depth owing to their technical and economic feasibility. In this study, the reliability analysis of bottom-fixed offshore wind turbines with monopile and/or multi-member lattice-type foundations is carried out and the sensitivities of random variables such as material properties, external wind loadings and scouring depth are compared with respect to different types of foundations. Numerical analysis of the NREL 5 MW wind turbine supported by monopile, tripod and jacket substructures shows that the uncertainties of soil properties affect the reliability index more significantly for the monopile-supported OWTs while the reliability index is not so sensitive to the material properties in the cases of tripod- and jacket-supported OWTs. In conclusion, the reliability analysis can be preliminarily carried out without considering soil-pile-interaction in the cases of tripod- and jacket-supported OWTs while it is very important to use the well-measured soil properties for reliable design of monopile-supported OWTs.

Comparative Analysis of Growth and Development of Paddy Rice (Oryza sativa L.) by Light Intensity under Farm-type Solar Photovoltanic Power Station (추적식 영농형 태양광발전시스템 구축에 따른 음영별 하부작물 벼(Oryza sativa L.)의 생육비교)

  • Eon-Yak Kim;Ye-Jin Lee;In-Jin Kang;Hye-Min Son;Min-Ho Shin;Chang-Hyu Bae
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2022.09a
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    • pp.85-85
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    • 2022
  • 영농형 태양광발전은 태양의 일사량을 전기발전과 영농에 공유하는(solar-sharing) 방식이다. 본 연구는 신재생에너지의 활용의 극대화를 위하여 추적식 영농형 태양광발전시스템을 구축하고 시설하부에서 일정 기간 재배중인 작물의 하부 환경과 생육을 조사하여 영농형태양광 하부작물개발을 위한 기초자료를 확보하고자 하였다. 구축한 추적식 영농형 태양광발전시스템은 4열 6단의 24장 모듈(8m × 6m)을 가지며, 발전시설 중심축 기둥 간 중심간격 14m로 단일지주식 스크루 공법으로 순천대학교 부속농장 답작포(순천시 죽평리)에 설치하여 하부 환경과 하부작물의 생육을 조사하였다. 태양광발전시설 하부작물의 생육을 조사하기 위하여 순천 농협육묘장에서 벼(신동진)를 육묘하여 2022년 6월 16일 이앙하였다. 태양광발전시스템 하부 지역을 4방위 방향에 따라 강음영(중심축으로부터 1~3m), 중음영(5m), 약음영(7~9m) 구역으로 설정하여 생육을 조사한 결과, 방위에 따른 초장은 남쪽에서 음영간 차이가 상대적으로 낮게 나타났으며, 1번기 태양광 발전시설에 의하여 음영이 중첩된 2번기 시설의 동쪽에서 대조구 대비 초장이 상대적으로 낮은 경향을 나타내었다. 음영강도에 따른 초장은 대체로 강음영구에서 낮게 나타났으며, 약음영구로 갈수록 높게 나타났다. 엽수는 방위에 따라서, 그리고 음영의 강도에 따른 차이가 초장에 비하여 작게 나타났다. 출수기의 경우 방위별로는 남쪽에서 음영별 차이가 작게 나타났으며, 음영강도에 따라서 차이를 보였다. 또한 태양광시설 하부에 데이터수집장치(Model 1650, Spctrum Technonogies, USA)를 설치하여 음영에 따른 토양전도도, 토양함수량, 토양온도, par light 등 생육환경을 조사, 비교하였다.

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Bearing Capacity of Foundation on Sand Overlying Soft Clay (연약한 점토층 위에 놓인 모래지반의 극한지지력에 관한 연구)

  • 민덕기;김효상
    • Journal of the Korean Geotechnical Society
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    • v.15 no.5
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    • pp.29-41
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    • 1999
  • This Paper applied a simple strength parameter averaging method to double layered systems consisting of the strong sand layer overlying the soft clay deposit. This study derived a formula which defines a critical depth as the strength parameters, and used the correction parameter, $\alpha$ to reduce an error of the strength parameter averaging method. The results of the method were presented in the form of dimensionless charts and were compared with the results of several solutions proposed by Satyanarayana & Grag, Sreenivasulu, and Meyerhof & Hanna. The results of the proposed method coincided with the method of Meyerhof & Hanna and the results obtained from FLAC. But the Satyanarayana & Grag method and the Sreenivasulu method overestimated the bearing capacity. Consequently, the bearing capacity of foundation on sand layer overlying soft clay layer can be approximately estimated by using the proposed dimensionless charts.

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A Basic Analysis of Behavior of Rectangular Prestressed Pilecolumn I (사각 프리스트레스트 말뚝형 기둥 기초적 특성 사례 연구 I)

  • Chon, Kyungsu;Kim, Nagyoung;Chung, Kyuchung
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.12
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    • pp.13-22
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    • 2013
  • A substructure of bridges is very important structural element for safety and supporting not only vertical loads as dead load and live load but lateral loads as break load, wind load, seismic load, hydrostatic pressure and dynamic water pressure, lateral earth pressure, impulsive load, temperature change and load effect of temperature change, creep and shrinkage. Most of domestic bridges are reinforced concrete piers and have an effect on economy of bridge. Recently, understanding importance of substructure, we are getting more interested in new substructure system.

Unconformity and Stratigraphy of late Quaternary Tidal Deposits, Namyang Bay, West Coast of Korea (한국 서해 남양만 조수 퇴적분지의 제 4기 퇴적층서와 부정합)

  • 박용안;최진용
    • 한국해양학회지
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    • v.30 no.4
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    • pp.332-340
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    • 1995
  • To study stratigraphy of tidal basin deposits, related unconformity and source of late Holocene tidal sediments in Namyang Bay, west coast of Korea, total 8 vibracore sediments have been analyzed. The uppermost stratigraphic sequence of the late Holocene Namyang intertidal deposit overlies three different stratigraphic sequences (1) oxidized reddish brown muddy deposit (Yongduri Member), (2) oxidized yellow deposit (Kanweoldo Formation) and (3) the pre-Cambrian gneiss complex unconformably. Accordingly, three unconformities between those different sequences are recognized. The Namyang tidal deposits (late Holocene) with several meter thickness are mostly coarsening upward sequence suggesting transgressive phase during a continuous rise of sea level. The tidal deposit vibracored down to 4.5 m in depth contains clastic glauconite sands (2% in average) from 2.5 m to the vibracore bottom. These glauconite sands are considered to be transported to the site of Namyang Bay tidal sedimentation from offshore continental shelf of the Yellow Sea along the course of late Holocene sea-level rise.

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Geomorphological Development of Palgye Alluvial Plain and Landscape Change of the Chilgok area, Northeastern Part of Daegu Metropolitan City (대구광역시 칠곡 팔계평야의 지형발달과 경관변화)

  • HWANG, Sangill;YOON, Soon-Ock;KANG, Chang-Hyeok;Lim, Won-Hyeon
    • Journal of The Geomorphological Association of Korea
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    • v.17 no.4
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    • pp.29-40
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    • 2010
  • The Palgye Plain, located in Chilgok, Buk-gu, Daegu-si, is a floodplain by Palgye-River rising from Mt. Ga one of the mountains in Ring Typed Mountains of Mt. Palgong. The geomorphic surfaces in the study area can be divided into the natural levee, back marsh and confluent fan, and the natural levee and fan have been used as important regions of human activities since the Bronze Age. The alluvium sediments of Palgye-River can be subdivided into the bedrocks, lower gravel deposits, lower sandy deposits, lower silty deposits, upper sand and gravel deposits, and upper silty deposits from the bottom according to the formative ages. The lower gravel deposits correlated to the last glacial stage and the rest to Holocene, respectively. Confluent fans were also formed during the last glacial stage. Moreover, The landscape with land use after 20C was changed to apartment area due to civilization differently from which reflected the characteristics of geomorphic surfaces in the past.