• Title/Summary/Keyword: soil cutting

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Effects of Environmental Factors on the Stability and Vegetation Survival in Cutting Slope of Forest Roads (임도 절토 비탈면의 안정과 식생활착에 미치는 환경인자의 영향)

  • Jung, Won-Ok
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.4 no.2
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    • pp.74-83
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    • 2001
  • The purpose of this study was investigate to the influence of forest roads characteristics and environment factors on the soil erosion, stability and vegetation survival of cut slope in forest roads. The results obtained could be summarized as follows; 1. The correlated factors between slope erosion and variables in cut slope were altitude, convex, degree of slope, length of slope and soil depth. In the stepwise regression analysis, length of slope and soil hardness was a high significant and its regression equation was given by -89.6136 + 15.0667X14 + 16.6713X15($R^2$ = 0.6712). 2. The main factors influencing the stability of cut slope were significant in order of coverage, middle, convex, length of slope and north, and its discriminant equation was given by -1.019 + 0.064X22 - 0.808X8 - 0.622X24 + 0.742X11 - 0.172X14 - 0.545X6 ($R^2$ = 0.793). 3. The centroids value of discriminant function in the stability and unstability estimated to 1.244 and -1.348, respectively. The boundary value between two groups related to slope stability was -0.1038. The prediction rate of discriminant function for stability evaluation of was as high as 91.3%. 4. The dominant species of invasion vegetation on the cut slope consist with Carex humilis, Agropyron tsukushiense var. transiens, Calamagrostis arundinacea, Miscanthus sinensis var. purpurascens, and Ixeris dentata in survey area. The rate of vegetation invasion more increased by time passed. 5. The life form of invasion vegetation in cut slop showed to $H-D_1-R_{2,3}-e$ type of the hemicryptophyte of dormancy form, dissem inated widely by wind and water of dissminule type, moderate extent and narrowest extent of radicoid type, erect form of growth form. 6. The correlated factors between forest enviroment and coverage appeared north, passage years and middle position of slope at 5% level. The forest environment factors influencing the invasion plants in survey area were shown in order to altitude, passage years, rock(none), forest type(mixed) and stone amount. The regression equation was given by 17.5228 - 0.0911X3 + 3.6189X28 15.8493X22 19.8544X25 + 0.3558X26 ($R^2$ = 0.4026).

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Habitat Characteristics and Distribution of Cymbidium kanran Native to Jejudo, Korea (제주한란의 자생환경 특성 및 분포에 관한 연구)

  • Lee, Jong Suk
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.7 no.1
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    • pp.40-49
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    • 2004
  • This work carried out to define the characteristic of Cymbidium kanran habitat at Mt. Halla in Jejudo, Korea from the ecological point of view including geological and topographical features, air and soil temperature, relative humidity, fluctuations of light intensity, habitat vegetation, distribution altitude, area limit, and etc. And another goal of this study consider the conservation counterplan of the cymbidium habitat. Natural distribution areas of the cymbidium were observed more abundantly on the well drained south and east-facing slopes. Soil acidity was ranged from pH 4.1 to 5.3, and electric conductivity was ranged from 176.4 to 299.9 us/cm (average 215.3 us/cm). Base-saturation percentage of the habitat soil was below 50%, bulk density 0.42g/$cm^2$, particle density 2.05g/$cm^2$, humus content 26%, total nitrogen 0.82%, available phosphate 4.2 mg/kg, exchangeable potassium 0.63 Cmol/kg, calcium 0.44 Cmol/kg and magnesium 0.67 Cmol/kg. Annual mean air temperature was $15.4^{\circ}C$, however, air temperature was ranged $11.7{\sim}18.2^{\circ}C$ in spring, $21.2{\sim}23.8^{\circ}C$ in summer, $12.8{\sim}22.0^{\circ}C$ in fall and $5.5{\sim}7.8^{\circ}C$ in winter season. Annual mean soil temperature at depth of 10cm was $13.2^{\circ}C$ And minimum value was recorded $4.7^{\circ}C$ on January, and maximum value $22.5^{\circ}C$ on August. Relative humidity was ranged 90.8~94.7% in summer, 80.8~91.5% in fall and 77.6~84.2% in winter season. Minimum value was 56.5% on December, and maximum value was 100% on July and August. Light intensities were ranged from 400 to 1,800 lux at the greater part of Cymbidium kanran sites in Jejudo. Summer regarded as an lower light intensities was recorded to be range of 500~600 lux; however, autumn and winter were shown higher light regimes ranged from 3,500 to 3,800 lux. Therefore, one must be suprised that the cymbidium grow at the light condition of 6 lux (minimum) or 10,000 lux (maximum). Tree species keeping higher frequency rate and density were Eurya japonica, Camellia japonica, Castanopsis cuspidata, Carpinus laxiflora and Pinus densiflora. Number of trees growing in a 5${\times}$5m quardrat was 35 as an average, and proportion of evergreen versus deciduous was 5:1. Distribution altitude of the orchid habitat was ranged from 120m (low) to 840m (high) from sea level on the south facing slope of Mt. Halla, and was ranged eastern borderline of Gujwaup, Bukjejugun to western boundaries of Jungmundong, Seogwipo city. For the stable conservation of Cymbidium kanran habitat, sunlight regimes must be increased more by means of cutting trees or twigs in the site.

Analysis of Forest Resources in Anmyondo for Forest Management Harmonizing with Nature (자연친화적(自然親和的)인 산림경영(山林經營)을 위한 안면도(安眠島) 산림자원(山林資源) 분석(分析))

  • Song, Ho Kyung;Lee, Sun;Heo, Won Mu;Lee, Mi Jeong
    • Journal of Korean Society of Forest Science
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    • v.89 no.2
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    • pp.185-197
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    • 2000
  • This study was carried out to research structure of forest vegetation and site condition, and supply basic data for conservation of pine forest and ecologically sustainable forest management and control in Anmyondo area. The forest of Anmyondo were largely classified as four forest community : Pinus densiflora community, Pinus thunbergii community, Pinus rigida community, and Quercus variabilis community. Organic matter, total nitrogen, and other nutrients in soil of the study area were relatively low, and average soil pH was 4.9. Soil texture was sandy clay or heavy clay and so the aeration and permeability could be poor. In this study site, the methods such as the promotion of germination of pine seeds through removal of forest floor and inducement of natural regeneration through such method as regeneration under shelter wood would be better than the method such as afforestation after clear-cutting for conservation the pine forests. Also, it will be a good method to practice tending for hardwood species in the dominant areas by hardwood species.

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A Study on the Wild Exochorda serratifolia for Landscape Horticuitural Cultivation (야생 가침박탈(Exochorda serratifolia)의 조경원예화에 관한 연구)

  • 이기선;한교필;박원조;김일섭
    • Journal of the Korean Institute of Landscape Architecture
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    • v.15 no.2
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    • pp.139-148
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    • 1987
  • Exochorda serratifolia, broad-leaved shrub has beautiful flowers and is resistant to cold, shade and decease. New this native plant is considered to be worth being exploited as the outstanding plant for landscaping and horticulture. So this study was executed to utilize Exochorda serratifolia as the planting material for landscaping and horticulture through the survey of its habitat environment and the experimennt of its seed physiology and germination, vegetative propagation, culture and utilization, etc.. The results are as follows ; 1. The color of the flower is white, blooming in the early and middle of May and the seeds ripen late in Sep.. 2. The elevation, elevation, gradient and direction of the native habitat were 250m, 20-25$^{\circ}$and northern side respectively. 3. The soil pH of the natural habitat was 5.3 and soil fertility was poor. 4. Exochorda serratifolia appeared as indicator within P. densiflora community and its neighboring species were Q. mongolica, Q. dentata, R. mucronulatum, L. obtusiloba, E. oxyphillus, C. heterolphylla, var thunbergii, etc.. 5. The optimum temperature for seed germination was found at 20$^{\circ}C$ and the longer the stratification period at 5$^{\circ}C$ was, the lower the germination rate was. 6. The treat merits of GA and Kinetin increased the seed germination rate, especially under the dark condition but their high concentrations decreased the seed germination rate. 7. The rooted rate of the greenwood cutting was the highest at IBA 100ppm plot of vermiculite bed but its high concentration decreased the rooted rate conspicuously. 8. In the tissue culture, the each 1.0 ppd plot of NAA, Kinetin and NAA 1.0ppm + Kinetin showed the best growth. And the mixture of NAA 1.0ppm and Kinetin showed better growth than the single treatment of NAA or Kinetin did. 9. Transplanted Exochorda serratifolia showed healthy growth with shaded environmental condition(42.1% light intensity), therefore they can be cultivated as a shade tolerant landscape plant. 10. It was considered that Exochorda serratifolia was applicable to group planting at shade places or under trees in parks, homes, etc..

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Numerical Analysis and Comparison of the Influence of Safety Factor Variations in Slope Stability During Rainy Season (우기시 비탈면 안전율 변화 인자의 영향에 대한 수치해석적 비교연구)

  • Song, Pyung-Hyun;Baek, Yong;You, Byung-Ok;Hwang, Young-Cheol
    • Journal of the Korean Geotechnical Society
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    • v.30 no.10
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    • pp.45-54
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    • 2014
  • Many studies have been made on investigation, design, explanation and treatments etc. to minimize slope failure. However, the problem is that failures of cutting slope and natural slope due to Typhoon and localized heavy rainfall are still not reduced. It is difficult to treat the problem by only strengthening the design standard. And it is very necessary to carry out design and safety analysis under the most suitable conditions considering foundation and rainfall characteristics. In this study, variations of safety factor were discussed from different aspects to investigate the influence of different parameters of rainfall and analysis conditions. Rainfall and foundation conditions are supposed to be the most sensitive parameters to slope stability, and numerical analysis were performed by changing parameters of the two conditions. Rainfall behavior is based on the domestic statistical rainfall and foundation condition is selected as unsaturated soils. Study results show that, application of rainfall characteristics in different area and parameters of unsaturated soils are responding sensitively to variations of slope safety. Therefore, the input parameters should be fully examined when performing the practical design.

Development of a Garlic Clove Planter for Film Mulching (I) - Analysis of Shape of Planted Soil Holes and Planted Positions of a Garlic - (필름 멀칭 적응형 마늘 파종기 개발(I) -토양 혈공 형상 및 마늘의 파종자세 분석-)

  • Choi, Cuck-Kyu;Park, Seok-Ho;Kang, Tae-Gyoung;Kwak, Tae-Yong;Kim, Young-Joo
    • Journal of Biosystems Engineering
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    • v.33 no.4
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    • pp.217-223
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    • 2008
  • In this study, a garlic clove planter which is capable of planting holes in soil and planting a clove at the same time was designed and tested for film mulched beds. Planting characteristics of the planter were measured through field experiment. Some characteristics were analyzed with multibody dynamic simulation software. Simulation was performed on opening time of the planting hopper. Measured characteristics were position, angle, and reposition amount of garlic in sowing hole. Experiment results showed that the planted position of garlic in planting was 23.0 mm from the hole wall. The reposition amount of garlic was varied with its position and angle when the planted garlic was pressed by an angled compaction wheel. In case of type II position, the position movement of garlic was larger than type I. Average position movement of type II was 11.5 mm at $20^{\circ}$ of compaction wheel angle. These data suggest that cutting diameter of film opening must be larger than 33 mm to provide enough space for garlic sprouting. Also, simulation results showed that the maximum opening time of the planting hopper was 0.26 second.

Model Test Study on the Earth Pressure of the Retaining Wall with the Relieving Platform (선반식 옹벽의 토압에 관한 모형시험 연구)

  • Kim, Byoungil;Yoo, Wankyu;Yang, Mirim;Park, Yongseok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.1C
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    • pp.27-35
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    • 2012
  • The relieving platform has the advantage of decreasing the total lateral earth pressure on the retaining wall and increasing the overall stability of the structure. Several modeling tests were performed to determine the earth pressure distribution on the retaining wall with a relieving platform and to compare it with that of the cantilever retaining wall. Different types of soil and angle of cutting surface were used to determine the effect of the soil characteristics and the backfill conditions on these earth pressure distributions. From the modeling tests, comparisons between the retaining wall with a relieving platform and the cantilever retaining wall show that the reduction of the lateral earth pressure and deformation of wall was indicated clearly on the retaining wall with a relieving platform. And the overall stability was increased by the relieving platform.

Studies on the Computer Controlled Vibratory Tillage (진동경운(振動耕耘)의 컴퓨터제어(制御)에 관(關)한 연구(硏究))

  • Lee, Ki Myung
    • Current Research on Agriculture and Life Sciences
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    • v.4
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    • pp.95-101
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    • 1986
  • A computer-controlled automatic vibratory tillage test equipment which attained minimum draft and power was developed. Three control program modes were developed and tested with this equipment. A computer simulation investigated the control performances of the above modes with the following primary results. 1) All of the three control modes converged to the same steady state when the velocity ratio was kept constant. 2) The control mode in which the blade frequency was twice of the soil shearing frequency (frequency control mode) showed optimum control with minimum draft and power, and also had greatest velocity convergence. 3) Results of the simulations showed the frequency control mode to have achieved the best control performance. The fluctuation of the draft reduction was less than 10% at various cutting depths and soil moistures.

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An Establishment of Database for Effective Design of Anti-Frost Heave Layer using Field Data (도로포장의 효율적 동상방지층 설계를 위한 현장 계측자료의 데이터베이스(DB) 구축)

  • Kim, Nak-Seok;Nam, Young-Kug;Cho, Gyu-Tae;Lee, Bum-Woo
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.3
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    • pp.43-47
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    • 2011
  • Korea has seasonal weathers which result in the frosting of soil in winter times, and the thawing of soil in spring. These climate characteristics result in the damaging of pavements, due to the repeated freezing and thawing of road pavements during winter and spring. In order to reduce these pavement damages, anti-frost heave layers are being specially installed, however it is being applied based on foreign researches, and therefore result in the waste of national budget. With this study, a database system was constructed for effective management and monitoring of measured temperatures and function data of 2 meters below the embankment, cut slope, and the cutting-embankment boundary, which are 15 regions picked by the frost index diagram. As the study result, an effective storage and management-purpose database was established for easy data searching and downloading for the pavement design engineers.

Effectiveness on the Inoculation of Arbuscular Mycorrhizal Fungi in Cutting of Grapevine (포도 삽목에서 내생 균근균 접종효과)

  • Wee, Chi-Do;An, Gi-Hong;Kim, Hong-Lim;Sohn, Bo-Kyoon
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.6
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    • pp.1002-1007
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    • 2010
  • The study was performed to investigate the influence on growth and development of grape-cuttings by arbuscular mycorrhizal (AM) fungi inoculation, AM colonization rate, and the phenomena of mycorrhizal association. Among the grape-cuttings, 'Kyoho' and 'Tamnara' cultivars inoculated with AM fungi showed significantly increase of leaf area, leaf number, total root length and root surface area than non-infected ones. But 'Cambell Early' did not showed any significant difference in total root length and root surface area even after the inoculation. The AM colonization rates in mycorrhizal inoculation treatment were 22.5-32.5% in total average after 8weeks, and were 29.6%, 28.8%, and 48.8% for 'Cambell Early', 'Tamnara', and 'Kyoho' respectively after 12weeks. The AM colonization rate marked very low level in non-colonization control plot.