• Journal of Korean Society of Rural Planning
• /
• v.23 no.2
• /
• pp.87-96
• /
• 2017

This study is a basic research with the aim of developing the method of judging the leakage zone by grasping the habitat characteristic of agricultural reservoir slope in inhabiting characteristics appear differently according to natural inhabiting environment. To this end, this study is intending to investigate slope vegetation using a quadrat technique at Sinheung reservoir located at Gwangsi-myeon, Yesan-gun, Chungnam, and to perform the analysis of importance value using relative frequency and relative coverage, etc. Also, this study intended to present the necessity of having to consider the eco-system of the relevant region in time of a reservoir slope afforestation for the time to come by suggesting that the reservoir slope vegetation after a stable period becomes similar to the regional vegetation by comparing this study result with the existing research which carried out the analysis of importance value of forest vegetation for Yesan Region. The reservoir slope vegetation is similar to the indicator species which appear in the regional forest vegetation, so there was a need to select afforestation species in the light of this in time of slope afforestation. As a result of the analysis of the importance value, this study grasped that there was an emergence characteristic similar to the vegetation at a birthplace of a forest fires because growth and development of forest trees, and perennial plants were restricted by annually implemented brush-cutting work, etc.; however, indigo plant and bush clover, etc. were found to show the characteristic differing from this. Consequently, this study was able to confirm that there is the necessity of having to create the Importance Value Table suited for reservoir slopes by region through a lot more data construction in the near future.

• Korean Journal of Computational Design and Engineering
• /
• v.7 no.3
• /
• pp.148-156
• /
• 2002

Most Rapid Prototyping (RP) processes adopt a solid Computer Aided Design (CAD) model, which will be sliced into thin layers of constant thickness in the building direction. Each cross-sectional layer is successively deposited and, simultaneously, bonded onto the previous layer; and eventually the stacked layers from a physical part of the model. A new RP process, the transfer-type Variable Lamination Manufacturing process using expandable polystyrene foam sheet (VLM-ST), has been developed to reduce building time and to improve the surface finish of parts with the thick layers and a sloping surface. This paper describes the generation of Unit Shape Layer (USL), the cutting path data of the linen. hotwire cutter for the VLM-ST process. USL is a three-dimensional layer with a thickness of more than 1 mm and a side slope, and it is the basic unit of cutting and building in the VLM-ST process. USL includes data such as layer thickness, positional coordinates, side angles of each layer, hotwire cutting speed, the heat input to the hotwire, and reference shape. The procedure of generating USL is as follows: (1)Generation of the mid-slice from the CAD model, (2)Conversion of the mid-slice into a simply connected domain, (3)Generation to the reference shape for the mid-slice, (4)Calculation of the rotation angle of the hotwire of the cutting system.

• The Journal of Engineering Geology
• /
• v.17 no.1 s.50
• /
• pp.101-113
• /
• 2007

A landslide was occurred due to soil cutting for construction to expand the Donghae express highway in Dong-hae-City, Korea. The total area of the landslide was about $9,550m^2$ with 100 m of width and 87m of height. The landslide was occurred due to the internal factor of the unstable geological structure including the clay layer and the external factor of continuous heavy rainfalls. As the result of field instrumentation during the landslide, the horizontal displacement of the slope ground increases with increasing the accumulated rainfall by continuous rainfall during the rainy season. Also, the depth of sliding failure was decided by the horizontal displacement distribution during landslide occurrence. It makes sure that the horizontal displacement starts from the depth of sliding failure and the depth of sliding failure matches well with the location of the clay layer. As the slope stability analysis using Bishop's Simplified Method at the landslide area, the safety factor of slope during the rainy season was 0.53. This safety factor of slope was enough to trigger the landslide at this area. The depth of sliding failure obtained by analytical method matches well with the depth of the clay layer.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.8 no.3
• /
• pp.13-20
• /
• 2005

This study was conducted to suggest the ecological restoration methods of the decomposed granite cut-slope by organic soil amendment materials. Field test carried out for the cut-slope with organic soil amendment materials method and other three revegetation methods in Cheongwon. Test revegetation plants were Festuca arundinacea, Lolium perenne, Dactylis glomerata, Lespedeza cyrtobotrya, and Arundinella hirta. The result of this study can be summarized as follows; 1. The soil hardness, the soil acidity, and the soil humidity of organic soil amendment materials method were at a suitable value for plants growth. And it was better as compared with other three revegetation methods of cutting-rock slopes. 2. The result of toxic substance investigation, all items were at a suitable for standard law. 3. During one year after seeding, most plants germinated and especially Festuca arundinacea and Dactylis glomerata grows well. Seedling numbers were 336.7 per $m^2$(after 6 months), 183.3 per $m^2$(after 10 months), and 353.3 per $m^2$(after 6 months). Ten months later after seeding, plants showed 80% ground coverage. Visual rate, plant height, and growth rate were excellence, Also, high plant growth in spring better than autumn.

• Journal of the Korean Geotechnical Society
• /
• v.15 no.6
• /
• pp.3-16
• /
• 1999

This paper presents the results of sensitivity analysis based on an example study to verify a newly developed reliability-based model for rock slopes considering uncertainties of discontinuities and failure modes-plane, wedge, and toppling. The parameters that are needed for sensitivity analysis are the variability of discontinuity properties (orientation and strength of discontinuities), the loading conditions, and the rock slope geometry. The variability in orientation and friction angle of discontinuities, which can not be considered in the deterministic analysis, has a great influence on the rock slope stability, The stability of rock slopes including failure modes is more influenced by the selection of dip direction of cutting rock face than any other design variables, The example study shows that the developed reliability-based analysis model can reasonably assess the stability of rock slope.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.03a
• /
• pp.171-178
• /
• 2005

It is unavoidable to be formed slopes under special circumstance of Korea where 70% of the whole area are composed of mountains when civil engineering projects such as roads, site developments are increased with industrial development and horizontal expansions of urban area. Moreover, stability of the slopes become one of quite important issues under special meteorological characteristics that over two-thirds of annual average rainfall are concentrated in summer season and the localized torrential downpour are getting more frequent recently. Resulting in these circumstances, partial slope failures by debris flow of the high water content soils are occurred frequently in cutting soil slopes. In this case of debris flow slope failure, slope declination method are selected for their stable recovery because it is impossible to recover entirely by existing recovery methods. Seeding or special grass planting methods are followed separately without exception. The method by which entire recover with bigger stability ratio would be possible and grass planting work would be done simultaneously is developed. In this study, the results of the tests including a real construction history in a failed slope using developed method are described

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.15 no.4
• /
• pp.8-15
• /
• 2016

Most machines lose a lot of energy due to friction. Wear due to friction also reduces performance. Therefore, it is important to reduce friction on the surface to improve energy efficiency and decrease wear. Surface texturing refers to making patterns on the surface for reducing friction. There are many surface texturing methods, such as using lasers, abrasive jet machining, and so on. Recently, mechanical manufacturing methods, such as cutting and grinding, have been highlighted. Among them, the grinding method has the advantage of making patterns in large areas quickly. Therefore, it is appropriate for surface texturing on large machines. This paper is a study on the slope change of the surface texturing pattern using grinding. Therefore, we researched the slopes of the patterns corresponding to "spindle speed and feed rate" and "curvature of workpiece surface" using a mathematical model and experiment. As a result, we made a proper mathematical model concerning our research. Therefore, using the mathematical model in this paper, we could predict the slope change of the pattern according to grinding conditions.

• Journal of the Korean Geosynthetics Society
• /
• v.6 no.2
• /
• pp.27-32
• /
• 2007

Analysis was performed using AHP (Analytic Hierarchy Process) technique for the determination of priority on the effect factors and the preferences on cut-slope reinforcing methods. The results from professional group, such as researchers, design engineers and construction engineers, show that stability, durability and environmental condition are the most important effect factors. The retaining wall and the cutting methods were predominant for stability, economical efficiency, and maintenance/management in the evaluation of preferences on the cut-slope reinforcing methods interpreted for the increasing method of safety factor.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.23 no.1
• /
• pp.86-102
• /
• 1981

The soil test data of 28 earth dams, scheduled to be constructed in Kore3, were selected for this study. The safety factors of their side slops were computed using Fellenius' "slice Method" by computer. The results summarized in this study are as follows; 1. Dam sections can be easily determined by fig.10 without a time consuming trial and error calculations of assumed sections. 2. For the economical design of earth dam sections, it was found that more cohesive soil was suitable for lower dams(dam height less than 25m) and soils with a higher friction angle was better for higher dams 3. In the case that used soil materials have the same Internal friction angle, side slope increase was almost same. 4. The relationship between side slope and friction angle was found as log.S=a tan ø+b (Fig. 7) 5. The relationship between side slope and cohesion (c) was also found as log. S=a c+b (Fig. 8) 6. The change of safety factors due to the change of central core materials was very little (Table-2) 7. The decrease of safety factors according to the unit weight increase of embankment materials was negligible. 8. In general the relationship between the wet unit weight and the saturated unit weight was r sat = (rt)$^2$+0. 140. This study will contribute to the determination of economic and safe planning and designing of earth dams, embankments and cutting side slopes.

• Asian Journal of Turfgrass Science
• /
• v.9 no.3
• /
• pp.173-185
• /
• 1995

Hydroseeding technique is a very popular method of revegetating slope areas through the control of soil erosion and stability by seeding grasses. This study was conducted to select turfgrass species and cultivars for hydroseeding. Experiment plots were established on various soil types and environmental conditions at Singar-Ansan high-way construction site. The investigation was designed in three cutting, one back-filling and other three spare sites with various seed mixtures. Results indicated that combinations of seed mixtures influenced seed germination and rates of surface cover. In a view of long term, vegetation shifts should be influenced by characters of slopes and micro-climate conditions. Hydroseeding did not show good results on rocky slope areas. Revegetation was only going on where there had soil. The combination of seed mixture with a higher rate of perennial ryegrass had relatively good revegetation with faster germination and seedling growth. Improved turf-type tall fescue Arid ⓡ and Falcon ⓡ seemed to have good environ-mental adaptation and drought tolerance. Wild or old type cultivars showed relatively slow green-up in spring and growth rates at the next year of seeding. For the harmonious landscaping with surrounding area, the combination of native grass mixture with cool-season grasses had good results. Slow and low revegetation rate at hack-filling site seemed to be caused by the poor development of capillary tubes in sub-soil. It was shown that a high correlation between seed germination and revegetation rate, and between three-month later coverage rate and final rate. The evaluation of coverage rate after three month seems to he acceptable to decide the accomplishment of hydroseeding results on rode side slopes.