• 제목/요약/키워드: soil conditions

검색결과 4,113건 처리시간 0.03초

Soil-structure interaction and axial force effect in structural vibration

  • Gao, H.;Kwok, K.C.S.;Samali, B.
    • Structural Engineering and Mechanics
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    • 제5권1호
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    • pp.1-19
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    • 1997
  • A numerical procedure for dynamic analysis of structures including lateral-torsional coupling, axial force effect and soil-structure interaction is presented in this study. A simple soil-structure system model has been designed for microcomputer applications capable of reflecting both kinematic and inertial soil-foundation interaction as well as the effect of this interaction on the superstructure response. A parametric study focusing on inertial soil-structure interaction is carried out through a simplified nine-degree of freedom building model with different foundation conditions. The inertial soil-structure interaction and axial force effects on a 20-storey building excited by an Australian earthquake is analysed through its top floor displacement time history and envelope values of structural maximum displacement and shear force.

장항제련소 주변 비소오염토양의 특성분석에 따른 토양세척 처리효율 평가 (Assessment of Soil Washing Efficiency for Arsenic Contaminated Site Adjacent to Jang Hang Refinery)

  • 문소영;오민아;정준교;최상일;이재영
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제16권1호
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    • pp.71-81
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    • 2011
  • Cause of contamination in the study area nearby Jang Hang Refinery is dust scattering in refinery stack, and soil washing treatment is one of the proper technologies for soil remediation in this area. Site conditions frequently limit the selection of a treatment process. A treatment technology may be eliminated based on the soil classification or physicochemical characteristics of soil. This study was assessed the soil washing efficiency by conducting of soil characteristic analysis in the vicinity of Jang Hang Refinery Stack within a 2 km radius. Also, it was decided about remedial range with comparative analysis of As in soil by Korean Standard Test Method before/after revision, whereupon As concentration in soil showed a increasing tendency after revision. As a result, the soil washing using the size separation of soil was determined through identifying of As species in the soil. In this site, only particle size distribution and water content of soil can provide the initial means of screening for the potential use of soil washing.

토양의 배수조건 차이가 참깨 수량성에 미치는 영향 (Yield Formations of Sesame(Sesamum indicum L.) as Affected by Different Conditions of Soil Drainage)

  • 최형국;구자옥;김용재;이돈길
    • 한국작물학회지
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    • 제27권3호
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    • pp.276-282
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    • 1982
  • 본 시험은 1981년에 참깨품종 "수원 9호"를 Pot에 공시하여 토양의 배수력 차이에 따른 참깨의 생육과 수량형성의 차이를 구명하고자 시도되었다. 즉 점토와 세사를 용량비(V/V Ratio)로 각각 0:100, 25:75, 50:50, 75:25 및 100:0가 되도록 혼합한 토양에 6일 간격 20mm 관수와 3일 간격 10mm 관수의 효과와 반응차이를 해석하였다. 토양의 용량비에 따른 수분의 배수성은 점토혼합율에 따라 거의 직선적으로 감소하는 경향이었다. 토양배수성 차이에 따른 참깨의 생육반응은 순세사토에서만 한해가 인정되므로 관수의 증대가 요구되었고 그 외의 배수조건의 차이에 따른 생육반응에는 통계적 유의차가 없었다. 수량구성요소 가운데서 수량에 기여도가 가장 컸던 것은 주당삭수로서 수량과 마찬가지로 점토와 사토가 75%:25%로 혼합된 조건 즉 배수성보다는 보습성이 양호한 토양에서 가장 많았으며 삭당입수나 등숙성은 선행형질인 주당삭수와의 부적상관 때문에 보습성 보다는 배수성이 양호한 토양에서 증대되는 경향을 나타내었다. 관수방법간에 이들 수량구성 특성의 차이는 없었으나 수량은 6일 간격 20mm보다 3일 간격 10mm 관수로서 보습력(점사율 75%:25%)이 높은 조건에서 최다수준이었으며 과도한 배수성이나 보습성의 조건에서는 뚜렷한 감수의 경향이었다.감수의 경향이었다.

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전단마찰시험에 의한 섬유혼합토와 지오그리드 사이의 마찰 특성 평가 (Friction Properties between Fiber-Mixed Soil and Geogrid by Shear Friction Tests)

  • 조삼덕;김진만;이광우;안주환
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2003년도 봄 학술발표회 논문집
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    • pp.813-820
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    • 2003
  • The shear friction tests using large direct shear test units were performed to evaluate the friction properties of fiber-mixed soil. The used materials and test conditions were flowing. Soils : SM and ML; mixing fibers : three types of polypropylene fibers(net type 38mm and 60mm, and line type 60mm), reinforcement : geogrid; mixing ratio:0.2% and 0.3%; degree of compaction : 85% and 95%. In the test results, the reinforcing effect of fiber mixed soil was confirmed.

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투수계수에 미치는 초음파의 영향 (Effect of Ultrasound on Permeability)

  • 목진만;김영욱;김지형
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2003년도 봄 학술발표회 논문집
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    • pp.613-620
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    • 2003
  • This study investigated the effect of ultrasound on the permeability of the granular soil. The investigation laboratory experiments, and laboratory tests were conducted under a broad range of conditions including energy levels of ultrasonic waves, time for the treatment, and type of the soil. The results of the study show that sonication enhances the permeability of the soil specimens significantly. The degree of varies with sonication power and duration of application, and type of soil.

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반복 평판재하시험을 통한 지오그리드 보강지반의 거동 특성 (Behavior of Geogrid-Reinforced Soil with Cyclic plate Load Test)

  • 신은철;김두환;이상조;이규진
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 1999년도 가을 학술발표회 논문집
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    • pp.285-292
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    • 1999
  • The cyclic plate load test were peformed to determine the behavior of reinforced soft ground with multiple layers of geogrid. Five series of test were conducted with varying the soil profile conditions which including the ground level, type of soil, and the thickness of each soil layer. The plate load test equipment was slightly modified to apply the cyclic load. Based on the cyclic plate load test results, the bearing capacity ratio(BCR), subbase modules, shear modules, the elastic rebound ratio, and reinforcing parameters are presented.

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불포화 자연토의 포화도에 따른 동전기 정화특성에 관한 실험적 연구

  • 김병일;김익현;김기년;김수삼
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2003년도 추계학술발표회
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    • pp.302-305
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    • 2003
  • The electrokinetic remediation tests for natural soil contaminated by lead are performed on unsaturated conditions, in which the degree of saturation is controlled through the changes in water content and the constant unit weight. At the degree of saturation of 70% the small acid range and electrical potential is developed. The changes in the water content are little above the saturation of 90%. But it is increased by 1.7 times at the degree of saturation of 70%. Finally, the efficiency of extraction is improved at 70% than 100%.

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경작조건별 농경지 비료성분의 거동특성에 관한 칼럼 연구

  • 최태범;이기철;장윤영
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2003년도 추계학술발표회
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    • pp.279-281
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    • 2003
  • This study is intended to give information on agricultural nonpoint source pollution and transport related to fertilizer application and irrigation practice. Field-simulated soil columns were set up and leaching studies on fertilizer components such as nitrogen and phosphorus were performed. Nitrogen and phosphorus in the leachate showed different trends in each column and nonpoint source pollution in agricultural areas may be expected to depend on planted crops, soil conditions, and climate as well as irrigation and fertilizing management.

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철도노반개량을 위한 고압분사 사례연구 - 해성점토지반에서의 강도증대효과를 중심으로- (A Case Study on the Improvement of Rail Road Subgrade using Super Injection Grouting Method - Strength Increase in Marine Clay -)

  • 천병식;최현석
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 1998년도 추계학술대회 논문집
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    • pp.103-110
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    • 1998
  • Several soil improvement methods are applied to stabilize soft ground. But their improvement effects are known to be reduced in view of strength under poor conditions such as marine clay. The purpose of this paper is to investigate the strength increase effects of super injection grouting on the marine clay, A series of laboratory tests and chemical analysis tests has been peformed. Through this study, the causes of strength inferiority of treated soil was analyzed and soil improvement effects of grouted soil was presented.

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Understanding to Enhance Efficiency of Nitrogen Uses in a Reclaimed Tidal Soil

  • Lee, Sang-Eun;Kim, Hye-Jin;Park, Mi-Suk;Chung, Doug-Young
    • 한국토양비료학회지
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    • 제45권6호
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    • pp.955-960
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    • 2012
  • 신간척지 토양 pH는 7.5 이상의 알카리성 토양으로 요소와 같은 화학비료 처리 시 휘산에 의한 손실이 증가하여 비료효율이 저감된다. 한편 퇴비와 같은 유기태질소를 함유하는 유기질비료를 처리하더라도 토양 내 Nitrosomonas나 Nitrobactor와 같은 미생물상이 미약하여 질산화과정이 미약하여 실질적 유기질비료의 효과를 기대하기 어렵다. 한편 논과 같이 초기부터 담수상태로 시작하는 토양에서는 식물체가 질소원을 양분으로 이용하기 전 탈질화과정을 거치거나 아니면 용탈과정을 통하여 손실이 발생한다. 따라서 토양 pH가 7.5 이상으로 증가함에 따라 요소형태로 토양에 가해진 질소원으로부터 암모니아가스 발생이 급격히 증가되면 실질적 질소질 비료의 이용효율이 저하된다. 따라서 pH7 이상의 간척지 토양에 요소를 질소원으로 처리 시 암모니 움태나 질산태 형태의 가급태 질소원은 매우 적을 것으로 추정된다. 그러므로 담수하에서의 간척지 토양의 산화환원 특성과 토양 pH에 따른 처리 비종과 처리 기술개발이 반드시 필요하다고 판단한다.