• Economic and Environmental Geology
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• v.41 no.3
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• pp.335-344
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• 2008

The acid rock drainage (ARD) production potential of rock was assessed for a tunnel construction area, Kimhae and the damage reduction strategy was discussed based on the ARD risk evaluation. The geology of the studied area consisted of Mesozoic quartz porphyry, sandstone, tuff and granite. Sulfides occurred as a disseminated type in quartz porphyry and granite, and a vein type in sandstone. Quartz porphyry and sandstone with a high content of sulfide were classified as a potentially ARD forming rock. The drainage originated from those rocks may acidify and contaminate the surrounding area during the tunnel construction. Therefore, the drainage should be treated before it is discharged. A slope stability problem due to the ARD was also expected and the coating technology was recommended for the reduction of ARD generation before the application of supplementary work for enhancing slope stability such as shotcrete and anchor. From the ARD risk analysis, those rocks should not be used as aggregate and be used as bank fill material with the system for the minimum contact with rain water and ground-water.

• Journal of the Korean GEO-environmental Society
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• v.17 no.12
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• pp.27-34
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• 2016

Many steepened slopes have become increasingly advantageous because of the desire to increase land usage and decrease site development costs. The proven concept of tensile reinforcement allows construction of slopes with far steeper face angles than the soils natural angle. Steepened slope face reinforced with improved soil can increase land usage substantially while providing a natural appearance. The paper presents composite reinforced earth with improved soil surface and geogrid-reinforced backfill. For the stability of the steepened slope, the behavior of the composite reinforced earth are validated and verified by case study and numerical analysis. The case study has performed to investigate the deformation of reinforce soil slope for 14 months. Its horizontal behavior by general vertical load shows within the safe range (0.5% of structure height). As a result of numerical analysis and case study, the reinforcement effect of the steepened slope technique using improved soil is sufficient to be constructed as reinforced soil slope.

• Journal of the Korean Geosynthetics Society
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• v.9 no.1
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• pp.47-57
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• 2010

Granular soils having a large particle size have been used as a filling material in the construction of foundation, harbor, dam, and so on. Consequently, the shear behavior of this granular soil plays a key role in respect of stability of structures. For example, soil particle crushing occurring at the interface between structure and soil and/or within soil mass can cause a disturbance of ground characteristics and consequently induce issues in respect of stability of structures. In order to investigate the shear behavior according to an existence and nonexistence of particle crushing, numerical analyses were conducted by using the DEM (Discrete Element Method)-based software program PFC2D (Particle Flow Code). By dividing soil particle bonding model into crushing model and noncrushing model, total four particle bonding models were simulated and their results were compared. Noncrushing model included one ball model and clump model, and crushing model included cluster model and Lobo-crushing model. The combinations of soil particle followed the research results of Lobo-Guerrero and Vallejo (2005) which were composed of eight circles. The results showed that the friction angle was in order of clump model > cluster model > one ball model. The particle bonding model compared to one ball model and noncrushing model compared to crushing model showed higher shear strength. It was also concluded that the model suggested by Lobo-Guerrero and Vallejo (2005) is not appropriate to simulate the soil particle crushing.

• Korean Journal of Environment and Ecology
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• v.29 no.3
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• pp.431-440
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• 2015

This study investigated the correlation between the trees planted on the slope of the first landfill where the landfill was completed and the soil environment. 69 plots (($7{\sim}20m{\times}5{\sim}20m$) were planted with 26 kinds of major trees in the first landfill slopes for vegetation survey. The survey was conducted from 2007 to 2009. Soil analysis from 2007 to 2008 was made on the basis of the injured index and the indicator species were selected. Depending on the rate of growth of the indicator species, seven survey locations were selected for soil sample analysis. 10 tree species appeared to adapt to the landfill environment. Among them, the coniferous trees were Pinus thunbergii (Seedling) and Juniperus chinensis and the deciduous trees were Quercus aliena, Salix preudo-lasiogyne, Castanea crenata (Seedling), Prunus armeniaca var. ansu, Quercus acutissima, Chionanthus retusus, Liriodendron tulipifera (Seedling) and Celtis sinensis. 8 species of trees did not adapt well to the landfill environment. Among them, two kinds were coniferous, the other six kinds were deciduous. In addition, judgment on the other 8 species of trees as to whether they adapted well or not was postponed. The species for which judgment was postponed included one coniferous tree and seven deciduous trees. Indicator species of injured index was the species that have more than 25 % of the defect. The soil was collected from where Catalpa ovata, Sophora japonica, Albizzia julibrissin and Acer palmatum were planted for analysis. According to the soil analysis, the soil pH showed that the soil was alkaline. Regarding the three phases of the soil, most sample soil showed 60 % for the solid phase or 55 % for the solid phase but with less than 10 % of gas phase. The organic matter content was found to be 0.14 to 2.52 %.

• Korean Journal of Environment and Ecology
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• v.24 no.2
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• pp.157-165
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• 2010

This study was carried out to suggest the basic data of planting method for construction of buffer green space based on the land use in case of reclaimed land by analyzing land structure, planting concept, and planting structure in buffer green space, Rokko Island, Kobe, Japan. Rokko Island(total area: 580ha) is divided into port and logistics industry area and urban area by constructing the box type large-scale buffer green space. The land structure of buffer green space were biased mounding type, parallel mounding type, and complex mounding type. The width of buffer green space was 50meters in case of northern area, from 28 to 32meters in case of eastern area, and 37.5meters in case of western area, and the slope of that was from 18 to 25 degrees and the height of that was from 2 to 15meters. There were applied landscape and buffer planting concept on the sea side area of northern buffer green space, on the other hand landscape and shade planting concept on the Inner city side area of that. According to the result of planting structure analysis of northern buffer green space, the main woody species were those of deciduous-evergreen species grow in warm-temperate forest zone such as Quercus glauca, Cinnamomum camphora, Machilus thunbergii, Elaeagnus maritima. The results of maximum number of species and planting density by $100mm^2$ was that 9 species 22 individuals in canopy layer, 9 species 15 individuals in understory layer, 3 species 67 individuals in shrub layer, and 14 species 104 individuals in total. The plant coverage of northern buffer green space based on the ecological planting method was from 69 to 139% in case of canopy layer, from 26 to 38% in case of understory layer, from 6 to 7% in case of shrub layer, and from 101 to 184% in total. Index of plant crown volume of northern buffer green space based on the ecological planting method was from 1.40 to $3.12m^3/m^2$ in case of canopy layer, from 0.43 to $0.55m^3/m^2$ in case of understory layer, $0.06m^3/m^2$ in case of shrub layer, and from 1.89 to $3.73m^3/m^2$ in total.