• 제목/요약/키워드: steep slope

검색결과 432건 처리시간 0.025초

기계화를 전제로 한 산간경사지답경지정리방안에 관한 연구(II) (A Study on the Methodology of Land-Consolidation Sloping Paddies in land Vallry for the Farm-Mechanization (II))

  • 황은
    • 한국농공학회지
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    • 제24권4호
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    • pp.57-68
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    • 1982
  • The paddy fiels slope located in Kangweon province Hwyongsung gun Gonggeun myon Shinchonri was considerably steep and so it was impossible to economically consolidate the field up to date. But for the porpose of farm mechanization, the field (32. 27ha) was consolidated by the auther under the assitance of the Ministry of Agriculture and Fishery and,;the Administration of Kangweon province. This paddy field consolidation was caused by the treatise on "Land-consolidation methods for farm mechanization in the steep-sloped paddy field", of which the auther is the same. The constrution was carried out from September, 1981 to April, 1982. During the 4esign and construction, some Peculiarities were found and discussed. That is, in design, besides the common condititions for a design, some special conditions were considered and written below; (1) The ranges of field slope in this design were 1/100-1/30. (2) Long sides of the land readjustment blocks must be arranged abreast contour line, and so they make the amount of cutting and banking decreased so as to take the maximum advantage of the configuration of the field. (3) In design, the main principles of dividing blocks were written below; i) First of all, long side of a block should be drawn straight abreast a contour line. ii) Long side of a block should arrange abreast contour line and make its length 100-150m, if not, l)reak the side in order to make a bended rectangle. iii) Length of a short side should be determinded within differences of elevation (0.6 -1. 2m) between the two adjacent blocks toward the normal to a contour line. iv) Length of a short side should be above 15m and the ratio of long and short side should be slso kept 1: (4-6). v) A new field surface leveling was determinded from the elevation which produce the least amount of cuttingand banking within the range of 0.6-1. 2m diffe rences of elevation between the two adjacent blocks. vi) In the course of dividing blocks with the same width along the line which was normal to a contour line, all blocks connot keep their shape in a retangle because of steep slope of the field and so on, and so it was also necessory to make some non-retanglar and small blocks such as a trianglar or trapezoidal shape, which was impossible to use some of farm machinery. But because this non-rectanglar and small blocks were divided, larger and many rectanglar blocks can be divided and construction cost can also be lowered. According to the conditions discussed above, the paddy field consolidation project designed and constructed. And the results of this study were obtained as below; (1) Three-forth of total cost of this paddy field consolidation was not construction cost, and these cost consist of land grading (1/4), road and canal construction cost (1/4) and the other cost (1/4) such as surveying or materials and 56 on. (2) The steeper the land slope, the greater cost was assigned for road and canal construction, and than land grading. (3) Curtailment of the road and canal construction cost depended on simplificating their strutures. (4) In the case of the land slopes were low, the land grading cost was high by 1: 1.4 in comparison with the road and canal construction cost, and conversely when the slops were steep, the road and canal construction cost was high by 1 : 5 in compa- rison with the land grading cost. (5) The densities of irrigation canal, drainage canal and trunk and branch road were 150. Sm/ha, 60. im/ha and 17. 4m/ha respectively. The density of irrigation canal of the area was high by 2 times in comparison with the average one of Kangweon Province, and the others were nearly the same. (6) Most farmers (above 85%) knew the effects of paddy field consolidation. The effects are; 1) Improvement of irrigation 2) Improvement of farm management 3) Improvement of transportarion 4) farm mechanization and 5) grouping of the scattered land. And the more farm modernization was accomplished by these projects, the more farmers wanted to live in their land. (7) In spite of the very steep sloped paddy field, the diminution rate of the net farm land caused by consolidation was 7.7% which was nearly the same as the one of Chulweon plain of Kangweon province. Land grading cost was 971, OOOwon/ha which was rather cheap by 13.2% than the one of Ghulweon plain, and unit construction cost was 5, 341, OOOwon/ha (included soil addition) which was also nearly the same as the one of Chulweon plain and FNFIA (The federation of national farmland improvement association).

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종자피복, 경사조절 및 토양멀칭 처리가 녹화식물의 발아와 생장에 미치는 영향 (Effects of Seed Coating, Slope Control and Soil Mulching on Seed Germination and Seedling Growth of Rehabilitation Plants)

  • 이병태;박종민
    • 한국환경복원기술학회지
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    • 제9권6호
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    • pp.38-51
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    • 2006
  • This study was carried out to improve rehabilitation effect by hydro-seeding methods on denuded slopes. Lespedeza cyrtobotrya, Indigofera pseudotinctoria, Arudinella hirta, Poa pratensis, and Lolium perenne were used in this study. The results of the germination and growth characteristics by seed coating, slope control and soil mulching treatments are summarized here. Seed coating of those plants had an effect on germination ratio, germination force, $LD_{50}$, and seedling growth of stem, leaf and root. The seed coating effect was highest for I. pseudotinctoria while the seedling growth was best for L. cyrtobotrya. Vermiculite+Talcum was the best coating material for germination and seedling growth of the plants. As the slopes were steeper, germination ratio was lower and seedling growth of stem and root decreased. Lots of seeds and soils were swept away when the slope was steep. Soil mulching was effective for germination, seedling growth of stem and root, and soil stabilization. It was more effective when the slope was steeper. Coir net was the most effective soil mulching material n this study.

확장형 완경사방정식에 기초한 Galerkin 유한요소 모형 (Galerkin Finite Element Model Based on Extended Mild-Slope Equation)

  • 정원무;이길성;박우선;채장원
    • 한국해안해양공학회지
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    • 제10권4호
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    • pp.174-186
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    • 1998
  • 본 연구에서는 지배방정식으로 확장형 완경사방정식을 사용하고 무한요소를 이용하여 방사조건을 처리하는 Galerkin 유한요소 모형을 수립하였다. 수립된 모형의 타당성과 적용성을 입증하기 위하여 Ippen and Goda((1963)의 완전개방 직사각형 모형항만에서의 항만 공진과 Sharp(1968) 및 Chandrasekera and Cheung(1997)의 원형 천뢰상을 전파하는 파랑 변형에 대한 수치해석을 실시하였다. 수리모형실험 및 복합요소 모형에 의한 결과와의 비교를 통하여 본 모형이 급경사 지형에도 매우 양호한 결과를 제시함을 확인하였다. 마지막으로 방파제의 대안으로 고려될 수 있는 원형 해저 우물을 설정하고 이를 지나는 파의 변형 특성을 검토하였다.

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지오그리드를 이용한 보강사면의 현장 계측 연구 (Site Monitoring and Analysis of the Reinforced Slope with geogrid)

  • 김진만;조삼덕;최봉혁
    • 한국지반신소재학회논문집
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    • 제2권3호
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    • pp.3-9
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    • 2003
  • 본 연구에서는 Jewell의 설계도표에 의해 설계된 보강사면의 시험시공을 통한 현장계측을 실시하여 현장 성토체의 다짐특성, 사면의 변형특성, 침하특성 등을 분석함으로써 지오그리드를 이용한 보강 사면의 적용성과 전체적인 안정성을 평가를 수행하였다. 안정성 평가 결과, Jewell의 설계도표에 의해 설계된 보강사면은 전체적으로 안정한 것으로 평가되었으며, 식생매트 포설에 따른 식생의 활착은 현재의 경과 시간만을 고려하면 외관상 안정된 식생 발아 상태를 보이나, 식생의 발아가 경사면에 비해 시공 포설 경계층에 집중되어 이에 대한 보완이 요구된다.

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고밀도 플라즈마 식각에 의한 CoTb과 CoZrNb 박막의 식각 특성 (Etch Characteristics of CoTb and CoZrNb Thin Films by High Density Plasma Etching)

  • 신별;박익현;정지원
    • Korean Chemical Engineering Research
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    • 제43권4호
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    • pp.531-536
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    • 2005
  • 포토리지스트 마스크로 패턴된 CoTb 및 CoZrNb 자성 박막에 대한 유도 결합 플라즈마 반응성 이온 식각이 $Cl_2/Ar$$C_2F_6/Ar$ 가스를 이용하여 진행되었고 식각 속도와 식각 프로파일 측면에서 조사되었다. $Cl_2$$C_2F_6$ 가스의 농도가 증가함에 따라서 자성 박막들의 식각 속도는 감소하였고 식각 경사는 낮아졌다. 자성 박막들의 식각 가스로서 $Cl_2/Ar$이 빠른 식각 속도와 가파른 식각 경사를 얻는데 있어서 $C_2F_6/Ar$ 보다 더 효과적이었다. Coil rf power의 증가는 플라즈마 내의 Ar 이온과 라디칼의 밀도를 증가시키고 dc bias voltage의 증가는 기판으로 스퍼터되는 Ar 이온의 에너지를 증가시키기 때문에 coil rf power와 dc bias voltage가 증가할수록 식각 속도와 식각 경사는 증가하였지만 패턴의 측면에서 재증착이 일어났다. 자성 박막들의 적층으로 형성된 magnetic tunnel junction stack에 고밀도 플라즈마 반응성 이온 식각을 적용하여, 높은 식각 경사와 재증착이 없는 깨끗한 식각 프로파일을 얻었다.

A Study on the Variation of Ground Safety Factor by Earthworks

  • Kim, Jinhwan;Kwon, O-Il;Baek, Yong;Kim, Chang-Yong
    • 지질공학
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    • 제24권3호
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    • pp.333-341
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    • 2014
  • The construction of roads, tunnels, and bridges results in changes to the local terrain that may influence the ground safety factor, which represents the stability of geotechnical structures. In this study, we assessed construction sites that had collapsed as a result of terrain change, and then simulated variation in the ground safety factor with respect to terrain change caused by road construction. We assumed steep slopes to simulate changes in terrain in a mountainous area and assumed that earthworks took place for road construction by cutting a platform into the slope and altering the slope angle of the terrain both above and below the road. We calculated values of the ground safety factor through a stability analysis of the slope both above and below the road, and examined the variation in the safety factor of the above- and below-road slopes with respect to changes in road width. We found that if the slope angle was the same above and below the road, then the change in the ground safety factor during/after road construction occurred in the slope below the road, and if the slope angle above the road differed from that below, then the change occurred in both the above- and below-road slopes. Furthermore, the ground safety factor was essentially constant for road widths exceeding 2-6 m, depending on both above- and below-road slope angle. The findings of this study can be used to guide the management of construction sites and to assess changes in ground stability during road construction work, particularly in the early stages of earthworks, when the road width is narrow.

Evaluation of unsaturated soil slope stability by incorporating soil-water characteristic curve

  • Zhai, Qian;Tian, Gang;Ye, Weimin;Rahardjo, Harianto;Dai, Guoliang;Wang, Shijun
    • Geomechanics and Engineering
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    • 제28권6호
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    • pp.637-644
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    • 2022
  • Loess soils are unsaturated and widely distributed in the northwest zone in China. Many steep slope of unsaturated are observed are observed to be naturally stable. However, a low factor of safety (FoS) for these slopes would be computed from the slope stability analysis following local code practices. It seems that the analyzed results following the local code practices do not agree with the real condition as observed in the field. It is commonly known that soil suction plays an important role in slope stability due to a higher shear strength of the unsaturated soil as compared with that of the saturated soil. In this paper, it is observed that the computed FoS can also be affected by unsaturated unit weight of the soil. However, the effect of unsaturated unit weight of the soil on the slope stability is commonly ignored in engineering practice. Therefore, both the effects of shear strength and unit weight of the unsaturated soil on the computed FoS of unsaturated soil slope are investigated in this study. It is observed that the unsaturated unit weight of soil on the computed FoS increases with increase in slope angle. It is also observed that the effects of the unsaturated shear strength and unsaturated unit weight on the computed FoS are more significant than the effect of 3D analyses compared to the 2D analyses on the FoS.

산지 태양광 발전시설의 지형 공간 데이터베이스 구축 및 사면 특성 분석 (Analysis of Slope Characteristics of Solar Power Plants in Gangwon Province based on Geospatial Database)

  • 김지호;송기일;윤찬영
    • 한국지반공학회논문집
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    • 제40권4호
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    • pp.155-167
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    • 2024
  • 국토의 70%가 산지인 우리나라는 많은 태양광 발전 시설이 산지에 설치되고 있다. 본 연구에서는 산지 재해와 관련하여 산지에 설치된 태양광 발전시설의 사면 특성을 분석하기 위해 663개소의 강원 산지 태양광 발전시설에 대하여 면적, 경사각, 경사향, 고도, 토심 등의 데이터베이스를 구축하였으며, GIS 기법을 활용하여 산지 태양광 발전시설의 사면 특성을 분석하였다. 분석 결과, 강원 산지에 설치된 태양광 발전시설의 면적은 606~320,718m2의 범위를 가지며, 산지 태양광 설치 허가 기준과 급경사지 판정 기준 이상의 경사를 가진 태양광 발전시설이 상당수 존재하는 것으로 나타났다. 또한, 태양광 발전시설은 대부분 산사태에 취약한 남향을 나타내고 있으며, 토심과 사면 경사 또는 지형고도와는 상관관계가 매우 낮은 것으로 나타났다.

경사도에 따른 CN보정에 의한 L-THIA 직접유출 모의 영향 평가 (The Effect of Slope-based Curve Number Adjustment on Direct Runoff Estimation by L-THIA)

  • 김종건;임경재;박윤식;허성구;박준호;안재훈;김기성;최중대
    • 한국물환경학회지
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    • 제23권6호
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    • pp.897-905
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    • 2007
  • Approximately 70% of Korea is composed of forest areas. Especially 48% of agricultural field is practiced at highland areas over 400 m in elevation in Kangwon province. Over 90% of highland agricultural farming is located at Kangwon province. Runoff characteristics at the mountainous area such as Kangwon province are largely affected by steep slopes, thus runoff estimation considering field slopes needs to be utilized for accurate estimation of direct runoff. Although many methods for runoff estimation are available, the Soil Conservation Service (SCS), now Natural Resource Conservation Service (NRCS), Curve Number (CN)-based method is used in this study. The CN values were obtained from many plot-years dataset obtained from mid-west areas of the United States, where most of the areas have less than 5% in slopes. Thus, the CN method is not suitable for accurate runoff estimation where significant areas are over 5% in slopes. Therefore, the CN values were adjusted based on the average slopes (25.8% at Doam-dam watershed) depending on the 5-day Antecedent Moisture Condition (AMC). In this study, the CN-based Long-Term Hydrologic Impact Assessment (L-THIA) direct runoff estimation model used and the Web-based Hydrograph Analysis Tool (WHAT) was used for direct runoff separation from the stream flow data. The $R^2$ value was 0.65 and the Nash-Sutcliffe coefficient value was 0.60 when no slope adjustment was made in CN method. However, the $R^2$ value was 0.69 and the Nash-Sutcliffe value was 0.69 with slope adjustment. As shown in this study, it is strongly recommended the slope adjustment in the CN direct runoff estimation should be made for accurate direct runoff prediction using the CN-based L-THIA model when applied to steep mountainous areas.

다중 로지스틱 모형에 의한 농경지 휴경잠재성 분석 - 경상남도 창녕군 이방면을 대상으로 - (An Analysis of the Fallow Potential in Agricultural Area by Multi-logistic Model - A Case Study of Ibang-myeon, Changnyeong-gun, Kyungsangnam-do -)

  • 박인환;장갑수;서동조
    • 환경영향평가
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    • 제15권1호
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    • pp.53-65
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    • 2006
  • Topographic condition is one of the most important things in farming activities. The topographic condition didn't matter for farming in the past because agricultural products had competitive power in the market. So farmers tried to extend their farms without any concern of topographic condition. We need less labor-consuming farming as industrial structure has been changed and the competitive power of the farming has been getting weak. This study analyzed the fallow potential in agricultural area by topographic condition so that we have got results as follows. Maps of elevation, slope, distance from roads and water resources were made for getting a fallow probability model in farms, and these 4 factors were used as independent variables while a variable on whether it is fallow or not is a dependent variable in logistic regression model. In an analysis of the fallow potential depending on farm land types, the fallow probability in fallow orchard showed the highest value of farm lands, 0.973. Cultivated orchard had 0.730 and upland had 0.616 of the fallow probability. The fields having high fallow potential had high elevation, steep slope, and long distance from water resources and roads. Especially, fields having a probability over 0.99 appeared in orchards, fallow uplands and single cropping uplands, which were recognized to have several disadvantages related to the fallow like as high elevation, steep slope, and long distance from water resources and roads. With the logistic analysis, the suitable farm lands appeared at 16.45m of the mean elevation, 1.89 degree of the mean slope, 39.91m of the average distance from water resources, and 32.39m of the average distance from roads. On the contrary, non-suitable land appeared at 114.7m of the mean elevation, 24.9 degree of the mean slope. The distance from roads was more important variable than the distance from water resources for analyzing suitable farm land.