• 한국환경복원기술학회지
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• 제5권6호
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• pp.9-13
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• 2002

This study has been performed to investigate the physical and mechanical characteristics of compaction, volume change and compressive strength for reinforced soil mixed with cement. And confirm the reinforcing effects with admixture such as cement. To this end, a series of compaction test and compression test was conducted for clayey soil(CL) and cement reinforced soil. In order to determine proper moisture content and mixing ratio, pilot test was carried out for soil and cement reinforced soil. And the mixing ratio of cement admixture was fixed 3%, 6%, 9% and 12% by the weight of dry soil. As the experimental results, the maximum dry unit weight(${\gamma}_{dmax}$) was increased with the mixing ratio and then shown the peak at 10% reinforced soil, but the optimum moisture content(OMC) and the volume change was decreased with the ratio increase. And the compressive strength volume change was decreased with mixing ratio increased.

• International Journal of Advanced Culture Technology
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• 제7권4호
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• pp.268-273
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• 2019

The apparent soil resistivity is used for estimating multilayer soil parameters, such as, layer's depth and soil resistivity. The soil parameters are estimated by continuously revising those parameters until the error between the measured and calculated apparent soil resistivity reaches to allowable level. The equation for calculating the apparent soil resistivity is complicated and time consumed, because it is composed of an infinite integral which includes a zero order Bessel's function of the first kind. In this paper, a fast algorithm for calculating the apparent soil resistivity of horizontal multilayer earth structure is proposed using exponential sampling method.

• 한국지반환경공학회 논문집
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• 제18권2호
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• pp.59-65
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• 2017

해양 매립 공사는 해저의 해성점토를 해수와 함께 준설하여 매립지로 이동시켜 매립지를 형성시키는 공사이다. 매립지가 형성되는 과정에서 준설토는 침강-퇴적-압밀 과정이 진행되며 이 과정에서 압밀과정은 소요되는 시간과 침하량이 크기 때문에 매립지를 계획하는 해양 매립 공사에서 매우 중요한 결정인자로 사용하게 된다. 준설토의 침하량과 소요되는 시간을 예측하기 위한 방법으로 국내에선 Yano가 제안한 Column 실험이 보편적으로 사용되고 있다. 그러나 Yano의 Column 실험은 준설토의 침강압밀특성을 확인하기 위해 장시간이 필요한 단점이 있다. 따라서 본 연구에서는 장시간이 소요되는 Column 실험의 단점을 보완해 단시간에 준설토의 침강압밀특성을 확인하기 위한 방법으로 원심모형실험을 활용하였다. 그 결과 효율적으로 준설토의 침강압밀특성을 확인하기 위해 원심모형실험을 활용할 수 있는 것으로 사료된다.

• 한국전자파학회논문지
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• 제27권7호
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• pp.660-663
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• 2016

본 논문에서는 초목 층 산란모델과 지표면 산란 모델을 이용하여 초목 층에서 수분함유량 측정에 초목 층과 레이다 파라미터가 갖는 영향에 대하여 분석하였다. $1^{st}$-order RTM(Radiative Transfer Model)을 이용하여 여러 상태의 초목 층 밀도와 입사각, 주파수, 편파를 갖는 데이터베이스를 생성하고, WCM(Water Cloud Model)과 Oh 모델을 이용하여 후방산란계수로부터 지표면 수분함유량을 추출하였다. 수분함유량 추출 에러를 예측하기 위해 추출한 수분함유량과 RTM의 입력 변수인 수분함유량을 비교하였다. 수분함유량 추출 에러로부터 초목 층에서의 수분함유량 측정에서 초목 층 밀도와 입사각, 주파수, 편파에 따른 초목 층과 레이다 파라미터의 영향을 분석하였다.

• 한국농공학회지
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• 제16권4호
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• pp.3555-3571
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• 1974

This experiment of which aim contribute to plan irrigation system so as to increase forage crop yields, was conducted to estimate evapotranspiration amount of forage crops and to find out system of consumed water in a pasture-ground. The results obtained by this study are as follows: 1. The general weather conditions which, were closely related to the evapotrannpiration of forage crops were nearly same as those of the average year with the exception that temperature of May and June were slightly low. 2. According to the investigation of potential evapotranspirations (P.E) or forage crops and its changes during growing periods, changes of tenday P.E. were high significant according to the harvesting period. P.E of Alfalfa of which yield was the largest was the biggest. Althrough the correlations between P.E. and meteorological factors were irregular oming to three-time harvesting, correlation between ten-day evapotraspiration amount and copper plated pan evaporation or solar radiation was high positive significant. 4. Predicting formulas of P.E. were led by weather factors, and also relatione between P.E. and weather factors were showed as figure. from the these formulas, P.E. may be calculated by weather factors. 5. Predicting formulas of P.E. were led by mean temperature and copper plated pan evaporation, and by mean temperature and solar radiation. As computed values and measured values showed in figure, these formulas were high signiflent. 6. In the total consumed soil water duration of 10 days which, was non-rain period from 12th to 21th of August, Alfalfa was the largest 48.1mm, second, Orchard grass 40.1mm and Fescue 37.6mm, and Ladino clover was the smallest 37.1mm, also, order of each forage crop yield amound. was same to the abov. Order of soil moisture extraction rate of soil layer of all the for forage crops dulation of ten-day was soil layer 1 which was largest, soil layer 2, 3, and 4 Reviewing the the first five-day and the second five day, in the first five-day, order of that of all the forage crops was same to the above, but in the second five-day, that of soil layer 2 or 3 was more than the of soil layer 1.

• 한국환경과학회지
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• 제8권3호
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• pp.379-386
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• 1999

The adsorption and leaching of organophosphorus pesticides (phenthoate, diazinon, methidathion) were investigated in Namwon soli(black volcanic soil), Aewol soil(very dark brown volcanic soil) and Mureung soil(dark brown nonvolcanic soil) sampled in Cheju Island. The Freundlich constant, K value, was 52.4, 31.3 and 27.7 for phenthoate, diazinon and methidathion in Namwonsoil, respectively and decreased in the order of phenthoate, diazinon and methidathion among the pesticides. The K value of phenthoate was 52.4, 15.9 and 5.9 for Namwon, Aewol and Mureung soil, respectively and was the highest for Namwon soil with very high organic matter content and cation exchange capacity(CEC). The Freundlich constant, 1/n, showed a high correlation with organic matter content, i.e., its value was less than unity for organic matter rich soil(Namwon soil) and greater than unity for organic matter poor soil(Mureung soil). Total recoveries of pesticides in soil and leachate with leaching in soil column, were in the range of about 74~86%. The leaching of pesticides was less for phenthate with high K values, and more for methidathion with low K values among the pesticides. It was slower for Namwon soil with high K values, and more for methidathion with low K values among the pesticides. It was slower for Namwon soil with high K values, and faster for Mureung soil with low K values among the soils.

• 한국토양비료학회지
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• 제29권4호
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• pp.336-341
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• 1996

경사지 토양에서 퇴비시용이 토양유실량과 토양의 이화학적 특성에 미치는 영향을 검토하기 위하여 1984년에 사양토, 양토, 식양토, 식토의 토양을 충진한 경사도 15%, 경사장 5m, 폭 2m, 길이 1.2m인 유저 Lysimeter를 설치하여 나지, 무토비, 퇴비구(1.5ton/10a)를 두고 보리-콩 작부체계로 경작해온 시험지에서 1990년과 1991년도에 조사한 2개년의 시험결과는 다음과 같다. 1. 토양유실량은 사양토, 식토, 양토, 식양토순으로 증가하였으며 물 유출량은 사양토, 양토, 식양토, 식토순으로 증가하였으나 침투수량은 이와 반대였다. 2. 퇴비 시용구와 무시용구의 토양유실량, 유출수량 및 침투수량의 증감비를 보면 토양유실량은 33.6~44.6%, 유출수량은 17.0~24.0% 감소하였고 침투수량은 17.1%~23.7% 증가하였다. 3. 토양유실량은 유출수량과 Y=-12.125 + 0.063 X(r = $0.970^{**}$)의 정 상관관계였고, 침투수량과는 Y = 43.415-0.096X(r = $0.917^{**}$)의 부의 상관관계였다. 4. 퇴비 시용으로 pH, OM, CEC, 유효인산, 치환성 염기함량, 공극율, 내수성 입단, 유효수분 함량이 증가하였다.

• 한국환경생태학회지
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• 제14권1호
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• pp.38-45
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• 2000

강원도 고성군 죽왕면과 토성면 일대의 소나무군락을 대상으로 1996년 4월에 발생한 산화에 따른 산림환경변화가 토양의 이화학성에 미치는 영향을 구명하기 위하여 비산화지역(NF) 산화후 비벌채지역(FNC), 산화후 벌채지역(FC) 및 산화후 조림지역(FCP)으로 분류하여 토양의 특성을 분석하였다. 전조사지역의 토성은 사질식양토이었고, 토양의 입경조성을 비교하면 비산화지역은 표토의 모래함량이 심토보다 낮았고, 점토함량은 높았지만 산화지역은 모두 표토의 모래함량이 점토에 비해 높았다. 토양공극 분포 중 전공극량은 지역별로 큰 차이가 없었으나, 조공극량과 투수성은 비산화지역 ＞ 산화후 비벌채지역 ＞ 산화후 조림지역 ＞ 산화후 벌채지역 순이었고, 세공극량과 가비중은 반대의 경향을 나타내었다. 이는 산화에 따른 산림환경변화로 지피식생이 제거되어 토양침식이 가속화되면서 토양 내 수분함유능력의 지표인 토양공극과 투수성에 큰 영향을 주면서 토양물리성을 악화시키고 있는 것으로 판단된다. 토양 pH는 비산화지역과 산화후 비벌채지역이 산화후 벌채지역과 조림지역보다 표토 및 심토 모두 높게 나타났다. 유기물함량 및 전질소함량 변화는 표토와 심토 모두 비산화지역＞ 산화후 비벌채지역＞ 산화후 조림지역＞ 산화후 벌채지역 순이었다. 양이온치환용량 및 치환성 양이온($K^{+}$ , $Na^{+}$ /, $Ca^{2+}$, $Mg^{2+}$)함량 변화는 모두 표토가 심토보다 높았으며, 지역별로는 비산화지역＞ 산화후 비벌채지역＞ 산화후 조림지역＞ 산화후 벌채지역 순으로, 이는 산화후 표토층의 침식으로 지력이 악화된 결과로 사료된다.

• 한국환경과학회지
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• 제19권9호
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• pp.1137-1142
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• 2010

This study proposes a guideline of a green roof system suitable for the local environment by verifying the growth of Zoysia japonica in a shallow, extensive, green roof system under rainfed condition. The experimental soil substrates into which excellent drought tolerance and creeping Z. japonica was planted were made with different soil thicknesses(15cm, 25cm) and soil mixing ratios(SL, $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$, $P_4P_4L_2$). The plant height, green coverage ratio, fresh weight, dry weight and chlorophyll contents of Z. japonica were investigated. For the soil thickness of 15cm, the plant height of Z. japonica was significantly as affected by the soil mixing ratio and it was shown in the order SL= $P_4P_4L_2$ < $P_7P_1L_2$ = $P_5P_3L_2$ < $P_6P_2L_2$. For the soil thickness of 25cm, the plant height was increased in order to SL < $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ < $P_4P_4L_2$. The green coverage ratio was not observed by soil the mixing ratio or soil thickness. However, the green coverage ratio was 86~90% with a good coverage rate overall. The chlorophyll contents of Z. japonica were not significantly affected by the soil mixing ratio in the soil thickness of 15cm, but were higher in the natural soil than in the artificial soil at 25cm soil thickness. The fresh weight and dry weight of Zoysia japonica were heavier in the 25cm thickness than in the 15cm thickness and in the artificial soil mixture than in the natural soil. The result indicated that the growth of Zoysia japonica was more effective in the 25cm soil thickness with artificial soil than in the 15cm soil thickness with natural soil in the green roof system under rainfed condition.

• 한국조경학회지
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• 제31권6호
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• pp.85-94
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• 2004

This study was carried out to analyze physicochemical properties according to the soil height and to the six types of sites that were used as planting ground in the reclaimed land from the sea, Gwangyang Bay. The physicochemical properties of the soil types were tested by t-test(p<0.01, 0.05), at each of the 6 planting ground sites(p<0.01, 0.05), and at each height(p<0.01) of the planting grounds. These areas were tested by ANOVA and were significantly different. Improved soil was better than reclaimed soil from the sea for Zelkova growth because the improved soil contained lower amounts of pH, ECe, N $a^{+}$, $Ca^{++}$, $Mg^{++}$ SAR. Due to freedom from variables such as salt content in the underground as well as the physical and chemical disturbance of the soil, favorable planting ground for tree growth was recorded at the higher grounds than at the lower ones. Soil detriment to the tree growth in the studied sites included elements such as soil hardness, and the distribution of sodium in the tree root systems. The planting grounds for the favorable growth of landscape trees were determined in the following order: the grounds of mounding> the coved ground of improved soil, and the filled ground of improved soil.l.l.l.