• Geomechanics and Engineering
• /
• v.20 no.3
• /
• pp.207-220
• /
• 2020

Clay soils have a big potential to become contaminated with the oil derivatives because they cover a vast area of the earth. The oil derivatives diffusion in the soil lead to soil contamination and changes the physical and mechanical properties of the soil specially clay soils. Soil stabilization by using new material is very important for geotechnical engineers in order to improve the engineering properties of the soil. The main subjects of this research are a- to investigate the effect of the cement and epoxy resin mixtures on the stabilization and on the mechanical parameters as well as the microstructural properties of clay soils contaminated with gasoline and kerosene, b- study on the phenomenon of clay concrete development. Practical engineering indexes such as Unconfined Compressive Strength (UCS), elastic modulus, toughness, elastic and plastic strains are all obtained during the course of experiments and are used to determine the optimum amount of additives (cement and epoxy resin) to reach a practical stabilization method. Microstructural tests were also conducted on the specimens to study the changes in the nature and texture of the soil. Results obtained indicated that by adding epoxy resin to the contaminated soil specimens, the strength and deformational properties are increased from 100 to 1500 times as that of original soils. Further, the UCS of some stabilized specimens reached 40 MPa which exceeded the strength of normal concrete. It is interesting to note that, in contrast to the normal concrete, the strength and deformational properties of such stabilized specimens (including UCS, toughness and strain at failure) are simultaneously increased which further indicate on suitability and applicability of the current stabilization method. It was also observed that increasing cement additive to the soil has negligible effect on the contaminated soils stabilized by epoxy resin. In addition, the epoxy resin showed a very good and satisfactory workability for the weakest and the most sensitive soils contaminated with oil derivatives.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.4 no.4
• /
• pp.333-342
• /
• 2002

World widely, the occurrences of earthquakes have been increased recently. Speculating from cases of earthquakes in the world, it is reported that damages have been made underground structures like cut-and-cover tunnels, especially on the upper of tunnel with a shallow depth and the backfilled area adjacently by earthquakes. Earthquakes have a tendency to increase recently in Korea but it is deficient in seismic design criteria. In this study, Shaking table test on both soil and EPS blocks was performed to analyze the efficiency of the seismic performance of the cut-and-cover tunnels according to characteristic of backfill materials and embanking material. It turned out to be effective in improving the seismic performance according to analysis of strain and bending stress of tunnel by earthquakes.

• Journal of the Korean Geosynthetics Society
• /
• v.7 no.2
• /
• pp.49-52
• /
• 2008

Most of waste sludge has generally been disposed in landfill site or dumped in the ocean, which will be banned by the content of its heavy metals according to London Dumping Convention in Korea. Therefore, environmentally friend methods are urgently required for the treatment and disposal of the sewage sludge. Thermal hydrolysis is one of the good treatment methods to solve the sludge problems. In this study, the physical and environmental testing was conducted to evaluate the feasibility of by-product cake from the thermal hydrolysis as liner or cover materials in landfill.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.41 no.4
• /
• pp.17-23
• /
• 2013

The purpose of this study was to provide information on management and apply it to a roadside ground cover plant understanding the capacity of calcium chloride in the plant. The experimental group was composed of the ratio control group of calcium chloride, 0.5%, 1.0%, and 3.0% in 500g of soil. Plant materials were selected and measured according to their ecological characteristics such as ground cover plant, Pachysandra terminalis, Hosta plantaginea, Trachelospermum asiaticum, Vitex rotundifolia, Euonymus japonica and Callicarpa japonica. The acidity of the amended soil was increased gradually depending on the treatment and conductivity was continually decreased. The EX-Ca increased after the treatment, but decreased in the middle of the experiment. Pachysandra terminalis, Trachelospermum asiaticum and Euonymus japonica were able to grow and survive at the ratio of 0.5%. Hosta plantaginea and Vitex rotundifolia were able to survive at the ratio of 1.0%. Hosta plantaginea, the possible state can absorb salts due to moisture and, can be applied to ground cover plants in the roadside. The growth and development of Callicarpa japonica was poor and the leaves were open to grow for calcium chloride treatment except the control group. It was concluded that Callicarpa japonica was very sensitive to calcium chloride.

• Korean Journal of Remote Sensing
• /
• v.19 no.6
• /
• pp.411-419
• /
• 2003

An area corresponding to the spatial resolution of optical remote sensor imagery often includes more than one pure surface material. In such case, a pixel value represents a mixture of spectral reflectance of several materials within it. This study attempts to apply the spectral mixture analysis on forest and to evaluate the information content of endmember fractions resulted from the spectral unmixing. Landsat-7 ETM+ image obtained over the study area in the Kwangneung Experimental Forest was initially geo-referenced and radiometrically corrected to reduce the atmospheric and topographic attenuations. Linear mixture model was applied to separate each pixel by the fraction of six endmember: deciduous, coniferous, soil, built-up, shadow, and rice/grass. The fractional values of six endmember could be used to separate forest cover in more detailed spatial scale. In addition, the soil fraction can be further used to extract the information related to the canopy closure. We also found that the shadow effect is more distinctive at coniferous stands.

• The Journal of the Korea Contents Association
• /
• v.11 no.3
• /
• pp.211-219
• /
• 2011

The illumination has a meaning of making surroundings brighter. Also, the illumination is a piece of equipment designed to decorate interior space. But the cover materials and designs of the lamp are not variously, in comparison with those of advanced nations. Consequently, this research introduces new styles of the indirect ceramic lamp. The soil is used for making covers of lamps to differ from existing similar lamps. Also, designs of traditional Korean image are used in the part of the cover. The structural part of new illuminating system will be introduced as well. The ceramic lamp with high quality will help to develop a new interior product and it will suffice the demand class who prefers quality goods. With the ceramic covered lamps, the growth of ceramic industrial development will be expected.

• Journal of the Korean GEO-environmental Society
• /
• v.10 no.1
• /
• pp.15-23
• /
• 2009

The aim of this study was an evaluation of closed non-sanitary landfill's stabilization degree and a determination of its an optimal reclamation method. In order to evaluate the stabilization degree, physical compositions of landfill wastes in 21 closed non-sanitary landfills were analyzed. There were 4 major items such as cover soils, organics, combustibles and incombustibles. With respect to the results of physical compositions, it was determined that the waste in 9 sampling sites of closed non-sanitary landfills after 10years of the relief time was not fully stabilized. The closed non-sanitary landfills must be reclaimed as soon as possible. The main material in closed non-sanitary landfills was cover soils and the highest content was 89.96%. Otherwise, the contents in sanitary landfills was small and 9.89~11.12%. Therefore, it was evaluated that the recovered soil by sorting transfer treatment could be reused as on-site cover soils of the reclamating non-sanitary landfills and/or constructing materials.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.19 no.6
• /
• pp.123-132
• /
• 2016

The study was to introduce the revegetation measures for the improvement of the landscape in October, 2012 on the slope; two and four years after the introduction, the slope was examined to see the status of the revegetation. The result is as follows. The result from examining the soil on the slope, the soil was Loamy sand; which infers that the soil is in a poor condition for improving the scenery. Examining the characteristics of the vegetation-base materials, the soil acidity was pH 6.4 to 6.7; and the soil hardness was 21 to 24mm (hardness quotient of soil), this can be considered a favourable condition, which has no effect on the growth and development of plants. When it comes to the discovery of the species in the area, Lotus corniculatus var., Silene armeria L., Papaver rhoeas, Trifolium pratense L. developed and grew in spring after two years. And in the summer, Lotus corniculatus var., Dianthus chinensis L., Cosmos bipinnatus, Coreopsis drummondii L., Trifolium pratense were founded. And there were Lotus corniculatus var., Dianthus chinensis L., Aster yomena, Coreopsis tinctoria, Trifolium pratense L. in the autumn. According to the examination conducting after four years, Lotus corniculatus var., Dianthus chinensis L., Silene armeria, Cosmos bipinnatus, Coreopsis drummondii L., Papaver rhoeas, Trifolium pratense L. were founded in the spring, and Lotus corniculatus var., Dianthus chinensis L., Cosmos bipinnatus, Coreopsis drummondii L., Trifolium pratense grew in the summer. Lotus corniculatus var., Dianthus chinensis L., Astragalus sinicus, Aster yomena, Coreopsis tinctoria, Trifolium pratense L. were discovered in the autumn. Among the exotic species founded in the area, were Festuca arundinacea, Lolium perenne, Festuca rubra. When it comes to the protection of vegetation and dominance, Lotus corniculatus var., Metaplexis japonica, Coreopsis drummondii L. are the dominant species among the spring plants; and Lotus corniculatus var., Trifolium repens L., Erigeron annuus (L.) Pers. were the dominant plants in the summer. In the autumn, Lotus corniculatus var., Coreopsis drummondii L., Poa pratensis appear to be the dominant plants. The colonies of Pinus densiflora and Castanea crenata var. were formed around the South Sejong IC. Part of the area is occupied by the colony of Alnus hirsuta Turcz. ex Rupr. In terms of shrub, there were Indigofera pseudo-tinctoria, Robinia pseudoacacia, and Rosa polyantha var. genuina NAKA. As ground cover plants, Sasa borealis, Rubus crataegifolius Bunge were founded.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.5 no.4
• /
• pp.1-9
• /
• 2002

This study is carried out to make the environmentally affinitive porous planting block for revegetation and to make a effective program for greening plans. The summary is shown below. 1. In order to get stronger intensity and distribute proper porosity in the block for planting, the cements mixed with fine soil were used and the finer in soil grains gives the stronger in intensity of the cements. Use of the furnace slag cements instead of the portland cements showed relatively stronger in intensity of the block. The intensity of the block became stronger when the mixed ratio of the cements to soil is 5 : 1, but the pore space ratio was lower. The percolate pH of the portland cements after one month of treatment was 13.1 but the percolate pH of the furnace slag cements was shown lower. To mold proper porous planting blocks, the proper combination of additives such as the dehydrating agent, elastic agent and adhesives into the mixture of cements and soil gives better effectives. 2. After molding the porous planting blocks, it gave a better result when the grains of the filler made of peat moss, upland soil and compound fertilizer were smaller than 2 mm in size. Shaking of the filling materials also gave the better result, but it took more time and cost much more. Therefore, it was better when the filling materials were mixed with water first then flew down for stuffing. 3. It was necessary to cover with soil after seeding or planting on the porous planting blocks. The proper thickness of the soil to help root development and keep moisture is about 3~5 cm. 4. The plants for planting on the porous planting block were required stronger in the growth condition of their roots and their environmental adaptability. The average germination percentage and rate of Platycodon grandiflorum on the porous planting block were 88.8% and 85% accordingly and their rate is very uniform. The germination rates of Dianthus superbus var. longicalycinus and Taraxacum officinale were more than 50%. These grass species, Chelidonium majus var. asiaticum, Lysimachia mauritiana and Scabiosa mansenensis were the suggested biennial grasses in the planting area where exchanging of the seedling or nursery plants was not necessary because their germination rates were 59.3, 45.6 and 40.3% accordingly. Viola kapsanensis, Chrysanthemum sp., Taraxacum sp. and Iris ensata var. spontanea are the grass species that could be used by seeding for greening. However, the germination rate of Solidago virga-aurea var. asiatica, Aster scaber and Lythrum anceps were lower than 10%. The coverage ratio of Ixeris stolonifera is more than 80% after 60 days seeding and the root length of most of species are more than 10 cm except Iris ensata var. spontanea and Platycodon grandiflorum because their root developed thicker than other species.

• Journal of the Korean Society of Safety
• /
• v.14 no.4
• /
• pp.135-141
• /
• 1999

This study is an experimental study to investigate the possibility of the utilization of paper ash as the cover, liner in waste disposal landfill and other construction materials. The sample used in these tests was obtained from Daehan paper mill. A series of tests were peformed to evaluate basic properties, compaction, permeability, compressive strength, consolidation, leaching, and CBR of paper ash. In order to investigate the soil engineering properties of paper ash, the test results were compared with those obtained of fly ash. The results of unconfined compression tests show that paper ash had a larger strength than the fly ash. Also, the maximum dry unit weight of paper ash was approximately 59～76.9% less than that of the fly ash. It was found from the results of leaching test that paper ash is classified as non-detrimental general wastes according to the waste management law.