• 제목/요약/키워드: Site/soil characteristics

검색결과 709건 처리시간 0.027초

유류오염 토양의 복원을 위한 열탈착 처리기술

  • 유동준;김영웅;박용규;오방일;구자공
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2001년도 추계학술발표회
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    • pp.111-114
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    • 2001
  • Thermal desorption process is valuable for the remediation of oil contaminated site. The system is physical separation process by volatizing oil contaminants from soil matrixes and is not designed to provide high levels of oil destruction. The process is not incineration, because the decomposition of oil materials is not the desired result, although some decomposition may occur. The physical and chemical properties that influence the design and operation of the system include boiling points, soil sorption characteristics, aqueous phase solubility, thermal stability, contaminating oil concentration, moisture contents, particle size distribution and etc.

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기초지반강성을 고려한 철골 건축구조물의 비선형 지진해석 (Nonlinear Seismic Analysis of Steel Structure Buildings Considering the Stiffnesses of the Foundation-Soil System)

  • 오영희;김용석
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2005년도 학술발표회 논문집
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    • pp.137-144
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    • 2005
  • Seismic responses of a building are affected due to the site soil conditions. In this study, linear time history seismic analysis and nonlinear pushover static seismic analysis were performed to estimate the base shear forces of the 3, 5 and 7-story steel structure buildings considering the rigid and soft soil conditions. According to the study results, the steel structure buildings designed for the gravity loads and wind load showed the elastic responses with the moderate earthquake of 0.11g, and the soft soil layer increased the displacement and the base shear force of a building. Therefore it is more resonable to perform an elastic seismic analysis of a building structure with the moderate earthquakes considering the characteristics of the soft soil layer.

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폐기물매립지의 흙-벤토나이트 혼합차수층 특성에 관한 연구 (A Study on Soil-Bentonite Mixed Liner Properties for Waste Landfill)

  • 홍성길;한봉수;장연수
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2001년도 봄 학술발표회 논문집
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    • pp.597-604
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    • 2001
  • In this study, the engineering characteristics of soil-bentonite mixed liner are investigated using the laboratory hydraulic conductivity and strength tests. The soil used for the liner is clayey silt in the site and the weathered granitic soil located near the waste landfill studied. Mixing ratio of the bentonite which satisfies the requirement of hydraulic conductivity is determined and the optimum mixing ratio of betonite is recommended for the landfill. After the mixed liner is constructed, the block samples of the constructed liner are obtained and the properties of interest satisfy the requirements of the liner of the landfill.

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준설토의 침강속도 추정모델의 개발 (A Model for Settling Rate of the Dredged Soil)

  • 윤상묵;장병욱;원정윤;김성필
    • 한국농공학회논문집
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    • 제47권1호
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    • pp.51-59
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    • 2005
  • The settling rate of the dredged soil may vary with mineral composition, grain size distribution, initial con contration and salt concentration of suspension of the site. A series of settling column test was performed to investigate the settling rate characteristics of solid suspension material from dredging and reclamation. The settling rate of soil mixed with various size of particles depended on clay fraction which showed a inherent flux. A model was developed to predict the particle flux of mixed soil from the clay flux and its applicability was verified.

쓰레기 매립지반의 지진거동 평가 (Seismic Response Evaluation of Waste Landfills)

  • 김기태;이지호;장연수
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2002년도 봄 학술발표회 논문집
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    • pp.767-772
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    • 2002
  • Free-field ground motion during earthquake is significantly affected by the local site conditions and it is essential in the seismic design to perform the accurate site-specific ground response analysis. In this paper, one-dimensional seismic characteristics of waste landfill are studied based on the vertical propagation of horizontal shear waves through the column of soil/waste. Seismic response analysis is peformed for short-period, long-period and artificial earthquake ground motions using a computer program for seismic response analysis of horizontally layered soil deposits. The computed peak ground accelerations are compared with the values calculated according to Korean seismic design guidelines. The analysis result shows that the long-period earthquake causes the largest peak ground acceleration while the artificial earthquake results in the smallest one.

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국내 안티몬폐기물에 의한 수질화학적 오염 사례연구 (Case Study of Hydrochemical Contamination by Antimony Waste Disposal in Korea)

  • 정찬호
    • 지질공학
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    • 제18권4호
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    • pp.471-482
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    • 2008
  • 이 연구는 충남 연기군 원성리에 소재하고 있는 안티몬공장에서 산업폐기물로 발생된 안티몬 폐기물을 매립지의 토양수, 인접하천수, 인근마을 지하수에서 안티몬을 포함한 일부 중금속에 의한 오염특성을 밝히고자 수행되었다. 하지만 현재 매립지는 수년전에 폐기물은 수거하여 다른 지역으로 옮긴 후 복토된 상태이다. 본 연구를 위하여 조사지역에서 지하수, 하천수, 토양수 총 35점을 채취하였고 대조마을에서 2점의 지하수를 채취하였다. 연구결과 매립지 농지의 토양수에는 안티몬의 농도가 대조마을 지하수보다 훨씬 높은 $48.75{\sim}74.81\;ppb$의 범위를 보여, 이는 주요 선진국 음용수 수질 기준치를 최고 수 십 배 상회한다. 매립지와 접한 하천수 3지점, 마을지하수의 1곳, 안티몬공장내 지하수 1점에서도 안티몬의 농도가 비교적 높게 검출되었다. 철, 망간 등의 중금속이 토양수 및 하천수에서 최고 6.5 ppm, 7.3 ppm으로 매우 높은 값을 보인다. 그러나 그 외 중금속은 일부 토양수, 하천수, 지하수에서 대조마을 지하수보다 높은 값을 보이지만 수질기준치에 비해 상당히 낮은 같을 보인다. 모든 물 시료의 화학적 유형은 Ca-$HCO_3$ 유형에서 Ca-($Cl+SO_4+NO_3$) 유형까지 넓게 분포한다. 토양수가 Ca - $SO_4$의 유형을 보이는 것은 안티몬이 매립되었던 폐기물의 환산화물의 함유에 기인하는 것으로 보인다. 일부지하수는 칼륨과 질산염 성분의 높은 값을 보여 비료와 생활오염물질에 의한 오염을 보인다. 결론적으로 폐기물을 매립지의 복토층 아래 토양내 아직도 상당량 안티몬 등 중금속이 존재하며, 이들이 인근 하천 및 지하수를 오염시키고 농작물까지 영향을 미칠 수 있으므로 적절한 방재 대책을 세워야 할 것이다. 본 연구는 국내 안티몬 폐기물에 의한 수질오염사례에 대한 최초의 연구결과로 환경부에서도 국가적 수질관리 차원에서 안티몬에 대한 대책을 세워야 할 것이다.

개발가능지의 분포면적(分布面積) (Area of Potential Arable Land Distributed on Hill side)

  • 엄기태
    • 한국토양비료학회지
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    • 제11권4호
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    • pp.235-245
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    • 1979
  • The land utilization of Korea composed about 22.7% of arable land, 66.9% of forest land and 10.4% for the rest like a house site, road, and lake etc. The ratio of arable land is too small as compared with forest land which is occuping two-thirds of Korea. The expansion of arable land by the reclamation will solve the food problems for increasing populations. First, we have to know the exact extents and distribution of reclaimable land but the reported total extent of reclaimable land in Korea is variable according to the authority which carried out the soil survey. The different reported data of reclaimable land is owing to the method and criteria of soil survey. 840,522ha in Land Capability Survey of the Farm Land Improvement Association and 321,203ha in the Forest Land Survey by the Office of Forest was reported but the Office of Rural Development said that total reclaimable land was 1,400,540ha including grazing and fruit land. To assume the extent of reclaimable land, the soil survey method and criteria of soil survey should be considered. It can be considered that the main reasons of less in extent of reclaimable land in the other authorities than the Office of Rural Development is due to the following. The grazing land and the fruits land are not included by the Farm Land Improvement Association and only relative forest is considered by the Office of Forest. The main purpose of soil survey carried out by the Office of Rural Development is to utilize land of Korea at most. The soil characteristics and potential productivity are considered in soil survey and the reported data was based on reconnaissance soil survey. The more accurate data will be find out by the end of 1979 when the detailed soil survey will be done. In selection of cropping system and management, the soil condition should be considered, because the soil characteristics of reslaimed land is less fertile than the arable lands.

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New site classification system and design response spectra in Korean seismic code

  • Kim, Dong-Soo;Manandhar, Satish;Cho, Hyung-Ik
    • Earthquakes and Structures
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    • 제15권1호
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    • pp.1-8
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    • 2018
  • A new site classification system and site coefficients based on local site conditions in Korea were developed and implemented as a part of minimum design load requirements for general seismic design. The new site classification system adopted bedrock depth and average shear wave velocity of soil above the bedrock as parameters for site classification. These code provisions were passed through a public hearing process before it was enacted. The public hearing process recommended to modify the naming of site classes and adjust the amplification factors so that the level of short-period amplification is suitable for economical seismic design. In this paper, the new code provisions were assessed using dynamic centrifuge tests and by comparing the design response spectra (DRS) with records from 2016 Gyeongju earthquake, the largest earthquake in history of instrumental seismic observation in Korea. The dynamic centrifuge tests were performed to simulate the representative Korean site conditions, such as shallow depth to bedrock and short-period amplification characteristics, and the results corroborated with the new DRS. The Gyeongju earthquake records also showed good agreement with the DRS. In summary, the new code provisions are reliable for representing the site amplification characteristic of shallow bedrock condition in Korea.

대기 중 PCBs의 PAS에 이용되는 여러 매체의 PCBs 침착 특성 (Depositional Characteristics of Atmospheric PCBs in Several Media Used Passive Air Samplers)

  • 천만영
    • 한국환경보건학회지
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    • 제39권2호
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    • pp.151-158
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    • 2013
  • Objective: This study was carried out to determine the depositional characteristics of pine needles, pine tree bark, moss, and soil, which are used as a passive air sampler (PAS) of atmospheric polychlorinated biphenyls (PCBs). Methods: All four media were sampled from the same site. PCB concentrations were analyzed by GC/MSD, and the lipid contents were measured using the gravimetric method. Results: The total PCB concentration (IUPAC No. 28, 52, 101, 138, 153, 180) was the highest in soil (227.97 pg/g dry), followed by pine needles (71.36 pg/g dry), pine tree bark (44.58 pg/g dry), then moss (21.91 pg/g dry). Pine needles contained the highest lipid contents (21.31 mg/g dry), whereas soil (10.01 mg/g dry), pine tree bark (4.85 mg/g dry), and moss (1.92 mg/g dry) contained less. The concentration of lower-chlorinated PCBs was relatively high in pine needles, pine tree bark and moss, but not in soil. The PCB concentrations were proportional to their lipid contents in pine needles, pine tree bark and moss, but a different trend was revealed in soil. Conclusions: The PCBs concentrations in the media were affected by various factors including atmospheric PCB concentrations, lipid contents, and depositional pathways. However, each of these factors had a varying influence depending on the type of medium.

Physicochemical Properties and Plant Coverage of Wood-based Growing Media on Slopes

  • Moon, Hong-Duk;Ha, Si Young;Jung, Ji Young;Yang, Jae-Kyung
    • Journal of the Korean Wood Science and Technology
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    • 제46권6호
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    • pp.645-655
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    • 2018
  • The use of wood waste as substrate for plant growth exemplifies a strategy for turning waste into resources. The overall objective of this research was to evaluate the effects of wood-based growing media on plant cover in a slope area. Moreover, we tried to find out what physicochemical properties affect plant cover on a slope. For treatments, we tested natural soil, soil mixed with wood-based growing medium (1:1, w/w), and wood-based growing medium by itself. Physical and chemical characteristics were evaluated after four months from the date of treatment application to the experimental slope site. Soil coverage with seedlings of Lespedeza cyrtobotrya was measured for plant growth evaluation. Physicochemical properties were altered by mixing the natural soil with wood-based growing medium. Particularly, soil moisture and organic matter contents were significantly changed in soils treated with wood-based growing medium compared to soil alone. We confirmed that plant coverage rate was high when wood-based growing medium was mixed with the natural soil. There was a significant linear relationship between moisture content and CEC (Cation Exchange Capacity) of all growth media tested and plant coverage. This result was expected, as moisture content tends to increase with organic matter content, such as in wood-based growing medium. In conclusion, the high moisture content of the wood-based growing medium was considered effective for plant growth in the experimental slope site, and this wood-based growing medium provides a means to improve the harmony between the slope and the surrounding environment.