• 한국토양비료학회지
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• 제46권6호
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• pp.549-555
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• 2013

Human influence on soil formation has dramatically increased as the development of human civilization and industry. Increase of anthropogenic soils induced research of those soils; classification, chemical and physical characteristics and plant growth of anthropogenic soils. However there have been no reports on soil pore properties from the anthropogenic soils so far. Therefore the objectives of this study were to test computer tomography (CT) to characterize physical properties of an anthropogenic paddy field soil and to find differences between natural and anthropogenic paddy field soils. Soil samples of a natural paddy field were taken from Ansung, Gyeonggi-do (Ansung site), and samples of an anthropogenic paddy field were from Gumi in Gyeongsangnam-do (Gasan) where paddy fields were remodeled in 2011-2012. Samples were taken at three different depths and analyzed for routine physical properties and CT scans. CT scan provided 3 dimensional images to calculate pore size, length and tortuosity of soil pores. Fractal analysis was applied to quantify pore structure within soil images. The results of measured physical properties (bulk density, porosity) did not show differences across depths and sites, but hardness and water content had differences. These differences repeated within the results of pore morphology. Top soil samples from both sites had greater pore numbers and sizes than others. Fractal analyses showed that top soils had more heterogeneous pore structures than others. The bottom layer of the Gasan site showed more degradation of pore properties than ploughpan and bottom layers from the Ansung site. These results concluded that anthropogenic soils may have more degraded pore properties as depth increases. The remodeled paddy fields may need more fundamental remediation to improve physical conditions. This study suggests that pore analyses using CT can provide important information of physical conditions from anthropogenic soils.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1998년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
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• pp.335-342
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• 1998

A soil-structure interaction (SSI) experiment is being conducted in a seismically active region in Hualien, Taiwan. To obtain earthquake data for quantifying SSI effects and providing a basis to benchmark analysis methods, a 1/4-th scale cylindrical concrete containment model similar in shape to that of a nuclear power plant containment was constructed in the field where both the containment model and its surrounding soil, surface and sub-surface, are extensively instrumented to record earthquake data. In between September 1993 and May 1996, fifteen earthquakes with Richter magnitudes ranging from 4.2 to 6.2 were recorded. The recorded data were analyzed to provide information on the response characteristics of the Hualien soil-structure system, the SSI effects and the ground motion characteristics. The ground response data were analyzed for their variations with depth, with distance from the model structure, and at the same depths along downhole arrays. Variations of soil stiffness and soil-structure system frequencies were also evaluated against maximum ground motion. In addition, the site soil properties were derived based on correlation analysis of the recorded data and then correlated with those from the geotechnical investigation data.

• 건축역사연구
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• 제16권5호
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• pp.55-66
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• 2007

Through analysing on construction cases of stupa built in A.D. 7,8th, I have researched about these : constructive methods of inner soil of stupa, spatial compositions, characteristics of structures, arrangements of inner soil and etc. And cases analysed are six ; Mireuksajiseoktap(stone pagoda of Mireuksa Temple site), Gameunsajisamcheumgseoktap(three storied stone pagoda of Gameunsa Temple site), Goseonsajisamcheungseoktap(three storied stone pagoda of Goseonsa Temple site), Wolseong nawolliocheungseoktap(five storied stone pagoda in Nawonri, Wolseong), Guksagokseoktap(three storied stone pagoda in Guksa valley), Giamgokseoktap(three storied stone pagoda in Giam valley). Additionally we researched about inner soil of Sacheonwangsaji tapji(basement of stone stupa site in Sacheonwang Temple site) to speculate on composition of Synthetically, the foundation could be divided as core space and outer space. ; the former as structural function and the latter as ornamental function. And the core area could be divided again as center column space and buffer space. The relationship between core spaces and its formation are as belows; First, according to the area of foundation and scale of stone pagoda, formations of core are differed. As the scale of stone pagoda goes bigger, and the area of foundation goes larger, the structure of stone pagoda comprised by center column type and layered-core which endure upper load independently. On the contrary, as the scale of stone pagoda goes smaller, and the area of foundation goes lesser, the structure of stone pagoda tend to use only center column to endure upper part. Second, spatial composition of core area is comprised as two spaces, one which endure upper load and buffer space which absorb side pressure and upper pressure. The buffer space tend to be used in case of those structures which could not endure side pressure or have lots of joint. In some cases, it was located below the cover stone of foundation and gained upper load. And in case that have not gained pressure from side stone, the buffer space are comprised by smalle stone or roof tile to get structural supplement.

• 한국환경복원기술학회지
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• 제16권6호
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• pp.109-117
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• 2013

This study was carried out to investigate the changes of plant species and soil physicochemical properties on green roofs established at Seoul Women's University in 2005, 2006 and 2007. The plant species and soil properties were investigated in 2013. The areas of green roof sites ranged $90{\sim}100m^2$. There were floras of vascular plants of 12 families, 20 genera and 22 species in the 2005 site, 24 families, 37 genera and 38 species in the 2006 site, 14 families, 27 genera and 31 species in the 2007 site. The total number of plant species decreased in the 2005 and 2006 sites and increased in the 2007 site since established. High proportion of dispersal type was barochory in the 2005 and 2006 site, and autochory in the 2007 site. And the proportion of the compositae family was high in the introduced plants over the sites for the all study sites. Average pH and organic matter concentration of green roof soil were ranged from 5.25 to 5.96 and 7.17 to 8.96% in study sites. The organic matter concentration and pH of green roof soil were lower in 2013 than in the three establishment years. Carbon concentration of green roof soil in the three study sites were ranged from 4.16 to 5.30% and total soil carbon in 10cm depth were ranged form 1.57 to $1.98kg/m^2$.

• 한국지하수토양환경학회지:지하수토양환경
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• 제15권6호
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• pp.53-63
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• 2010

Pneumatic fracturing is an emerging tool to enhance the remediation efficiency of contaminated unsaturated zones by injecting high pressure air and inducing artificial fracture networks. Pneumatic fracturing is reported to be well suited for the cases where the contaminated unsaturated zone thickness is less than 5 m as many contaminated domestic sites in Korea. Nevertheless, there have been almost no studies carried out on the site-specific efficiency and the optimized design of pneumatic fracturing considering the unsaturated zone characteristics of Korea. In this study, we employ numerical simulations to compare the efficiency of pneumatic fracturing on the aspect of the site remediation and the porosity improvement at several hypothetic unsaturated zones composed of four typical soil types. According to the simulation results, it is found that the zone with fine grains soil such as clay and silt shows better efficiency than the zone composed of coarse grains in terms of air flow and porosity enhancements. The results imply that pneumatic fracturing may improve the efficiency of site reclamation by jointly or independently applied to the many contaminated sites in Korea.

• 자원환경지질
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• 제43권6호
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• pp.543-553
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• 2010

이 연구는 부여 정동리 꿩바윗골 유적에서 출토된 백제시대 경작토양의 광물학적 및 지구화학적 특정을 조사하고, 이를 사용하여 제작한 것으로 추정되는 무령왕릉 및 송산리 전(벽돌)과 토양을 비교하여 태토로서의 가능성을 검토하였다. 연구대상 토양시료들은 모두 미사질 양토로 가장 하부층을 제외하고는 모두 유사한 토양입도를 가지고 있다. 토양은 산성으로 일부 시료에서 유기물, P, S 등의 집적현상이 나타났다. 또한 지구화학적 원소 분포경향이 유사하며 석영, 사장석, 정장석, 질석, 운모, 고령석 등으로 구성되어 동일한 광물조성을 보인다. 부분적으로 붉은 철산화물의 농집이 관찰되는데, 강의 범람과 배수에 따른 산화와 환원환경이 반복되었던 환경이 토양 내 철산화물의 농집을 일으킨것으로 보인다. 이는 자연현상과 인간의 경작활동에 의한 풍화양상으로 볼 수 있다. 특히 무령왕릉과 송산리고분군 출토 전에서 발견되는 철산화물의 농집현상은 연구지역 토양이 전의 태도로 추정될 수 있는 추가적인 증거로 판단된다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2007년 가을학술발표회
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• pp.305-316
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• 2007

Free field ground motion during earthquake is significantly affected by the local soil conditions and it is essential for the seismic design to perform the site specific ground response analysis. So, Round Robin Test (RRT) on ground response analysis was performed for three sites in Korea. A total of 12 teams presented the results of ground response analysis with used input soil properties based on own judgement. In this paper, the results of one dimensional equivalent linear analysis presented by 11 teams were compared to evaluate the effect of input soil properties on ground response analysis. Additionally, 4 influence factors on ground response analysis, that is shear wave velocity of soil layer, nonlinear dynamic deformational characteristics, bedrock depth and bedrock velocity were studied for assumed simple soil conditions.

• Structural Engineering and Mechanics
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• 제71권4호
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• pp.445-458
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• 2019

This study mainly aims to assess the performance of soil-structure systems designed by direct displacement-based method coupled with strong column-weak beam design concept through various system identification techniques under strong ground motions. To this end, various system identification methods are employed to evaluate the dynamic characteristics of a structure (i.e., modal frequency, system damping, mode shapes, and plastic hinge formation pattern) under a strong seismic excitation considering soil-structure interaction for different site conditions as specified by ASCE 7-10. The scope of the study narrowed down to the code-complying low- to high-rise steel moment resisting frames with various heights (4, 8, 12, 16-story). The comparison of the result of soil-structure systems with fix-based support condition indicates that the modal frequencies of these systems are highly influenced by the structure heights, specifically for the softer soils. This trend is more significant for higher modes of the system which can considerably dominate the response of structures in which the higher modes have more contribution in dynamic response. Amongst all studied modes of the vibration, the damping ratio estimated for the first mode is relatively the closet to the initial assumed damping ratios. Moreover, it was found that fewer plastic hinges are developed in the structure of soil-structure systems with a softer soil which contradicts the general expectation of higher damageability of such structural systems.

• 한국환경생태학회지
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• 제18권2호
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• pp.210-220
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• 2004

본 연구의 목적은 미선나무 자생지의 환경특성과 생육특성을 분석함으로써 보전 및 복원의 기초자료 제공을 위한 것이다. 토양의 종류는 사양토, 식양토, 미사질양토이고 화학적 특성간 상관성은 전질소량과 양이온치환용량이 높게 나타났다. 생육특성의 경우 수고와 줄기직경은 I지역에서, 수관폭은 II지역에서, 엽수는 V지역에서, 종자수는 IV지역에서 타 지역에 비해 양호하였다. 생육특성에 대한 상관성에서는 수폭과 줄기직경이 높게 나타났다. 생장특성과 토양의 화학적 특성은 전기전도도와 수고가 높은 상관성을 보였다. 생육특성과 토양의 화학적 특성에 대한 회귀분석 결과, 수고와 전기전도도의 설명력은 약 70.4%. 엽수와 전질소량은 약 70.2%였다. 미선나무 자생지 보전 및 복원을 위해서 광도, 온도, 유전형질 등 다양한 인자들이 고려된 정밀 환경분석이 요구되어진다.

• 한국연초학회지
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• 제21권2호
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• pp.136-143
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• 1999

This study was conducted to evaluate the degradation characteristics of waste cigarette filters under 0, 5, 10, and 15cm in depth from soil surface by environmental conditions. Weather was the most important factor during degradation of waste cigarette filters in this study. Bulking of cellulose acetate filaments exposed on soil surface was observed after 2 months, but the form of filter was kept up after 12 months. The treated cigarette filters in soil landfill revealed a little different degradation pattern at each soil landfill depth, The sample in 5cm depth of soil was more degraded then other site. A fluffy appearance of cellulose acetate filaments in the control filter rods was also developed more strongly in soil landfill then on soil surface. From the observation of waste cigarette filters by scanning electron microscopy, much degradation of the fiber of waste cigarette filters could be ascertained in soil landfill. The weight of waste cigarette filters under 5cm from soil surface was reduced about 50%, and the tensile strength of the samples in soil surface and under 5cm from soil surface were reduced 66.0% and 92.4%, respectively. The microbial experiment date that the viable cell number in microbial population and cellulolytic microorganisms showed the maximum values under 5cm from soil surface, suggest that microorganisms in soil play an important roll in the degradation of acetate cigarette filters.