• Journal of the Korean GEO-environmental Society
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• v.14 no.3
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• pp.41-49
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• 2013

The rotate penetration pile is a type of displacement pile: the surrounding soil is displaced when installing the pile, and the pile can exert a large bearing power and pullout force. In addition, it uses displaced soil method that does not generate slime, and its applications are increasing in foreign countries owing to the environmentally friendly characteristics such as small noise and vibration. However, mostly driven piles-which are directly driven to the ground, and bored pile- pre-fabricated piles are buried to prebored underground, are used; however, rotate penetration piles still have limited use. Most of the laboratory tests have been carried out until now to identify the support behavior after installation of piles and ground construction, the evaluating the support behavior is lacking due to the rotation intrusive process of the rotate penetration piles. Therefore, this study used indoor experiments simulating rotation intrusive process in weathered soil, to evaluate the bearing power behavior for the weathered soil, varying the diameter of the helical bearing plates, helical bearing plate spacing, number of the helical bearing plates, and helical bearing plate specifications. As the outcome of this study, the helical pile bearing power evaluation results, change in bearing power in accordance with main specifications, and review on the comparative analysis with the existing theories were provided.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1052-1062
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• 2011

Residual of heavy metals originated from abandoned metal mines in agricultural field can cause adverse effect on ecosystem and eventually on human health. For this reason, remediation of heavy metal contaminated agriculture field is a critical issue. In this study, five different amendments, agriculture lime, dolomite, steel slag, zeolite, and compost, were evaluated for stabilization efficiency of heavy metals in agricultural field. Applied mixing ratio of amendments was varied (2% or 6%) depending on properties of amendments. Result showed that soil pH was increased compared to control (6.1-6.7) after mixing with amendments and ordered as dolomite (7.2~8.3) > steel slag (6.7~8.1) > agriculture lime (6.6~7.4) > zeolite (6.2~6.9) > compost (6.1~7.1). Among other amendments, agriculture lime, steel slag, and dolomite showed the highest stabilization efficiency of heavy metals in soil. For Cd, stabilization efficiency was 49~72%, 51~83%, and 0~36% for agriculture lime, steel slag, and dolomite respectively. In case of Pb, 43~64, 37~73%, and 51~73% of stabilization efficiency was observed for agriculture lime, steel slag, and dolomite respectively. However, minimal effect of heavy metal stabilization was observed for zeolite and compost. Based on result of this study, amendments that can increase the soil pH were the most efficient to stabilize heavy metal residuals and can be adapted for remediation purpose in agricultural field.

• Journal of the Korean Geotechnical Society
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• v.23 no.6
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• pp.53-66
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• 2007

A series of model tests were performed to investigate the soil arching effect in embankments supported by piles with geosynthetics. In the model tests, model piles with isolated cap were inserted through the holes in a steel plate, which could be operated up and down. Then geosynthetics was laid on the pile caps below sand fills. The settlement of soft ground was simulated by lowering the plate. As the plate was lowered, the soil arching was mobilized in the embankments. The deformation of both the sand fills and geosynthetics were captured by camera. Also the loads acting on pile cap and the tensile strain of geosynthetics were monitored by data logging system. Model tests showed that the embankment loads transferred on pile cap by soil arching Increased rapidly with settlement of the soft ground. In case of the absence of geosynthetics, the loads acting on pile caps dropped to residual value after peak value, whereas loads on pile caps gradually increased until constant value in case of geosynthetic-reinforced. This illustrated that reinforcing with the geosynthetics has a good effect to restrain the settlement of embankments. Also, the deformation shape of geosynthetics between pile caps was circular. The embankment loads transferred on pile caps can be estimated by considering both soil arching and tensile strain of geosynthetics in embankments supported by piles with geosynthetics.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.1120-1125
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• 2006

Larger area will be constructed in a harbor land and container terminal which are constructed in reclaimed land using the dredged materials. Soil improvement work is to be carried out including constructibility, in which is monitoring devices, measuring frequency, installations etc. The ground water tables in the reclaimed area are affected by the several factors which are design reclamation level, consolidation settlement, remaining surcharge pressure and remaining excess pore water pressure. The plan wii be drawn up in which monitoring results for the ground water tables are capable to provide the reliable ground water table when designers and civil engineers construct the harbor structures considering constructibility.

• Economic and Environmental Geology
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• v.37 no.4
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• pp.383-389
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• 2004

Understanding flow pattern of water and solute in subsurface is essential for the reduction and prevention of contamination of soil and groundwater and for the investigation and remediation of contaminated site. The objective of this study is to examine the infiltration pattern in a soil developed from the Jurassic granite using (Brilliant Blue FCF $C_{37}H_{34}N_{2}Na_{2}O_{9}S_{3}$), the nonfluorescent and nontoxic food dye. All image processing was conducted using geographic image processing software, ER Mapper, Version 6.2. The dye coverage was determined by counting the stained pixels in the photographs (80${\times}$80cm, 80TEX>${\times}$5cm) for the vertical and horizontal view. A homogeneous matrix flow occurred in the A horizon with weak, medium granular structure and fingering at the interface of finer-textured A horizon and coarser-textured C horizon. Pegmatitic vein originated from the granite and plant root in C horizon induced preferential flow.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.2
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• pp.145-153
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• 2004

H$_2$SO$_4$ and citric acid were used as additives for the electrokinetic remediation experiment to increase removal efficiency of $^{137}$ Cs and $^{60}$ Co from the radioactive soil waste stored for more than 10 years. The average effluent velocity discharged from the elctrokinectic remediation experimental column was 2.0${\times}$10$^{-2}$ cm/min and the discharged soil wastewater volume for 10 days is 3.6 pore volume of the column. 97% of $^{60}$ Co in the column was decontaminated for 10 days of operation, while only 54% of $^{137}$ Cs was decontaminated. These results are considered that the absorption equilibrium coefficient of $^{137}$ Cs is higher than that of $^{60}$ Co. The predicted values of the residual concentration by the proposed mathematical model were well coincided with the experimental results within the experimental error range

• Journal of Soil and Groundwater Environment
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• v.6 no.1
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• pp.13-21
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• 2001

The characteristics of $Co^{2+}$ removal in the kaolinite column were analyzed by electrokinetic remediation. Ethanoic buffer was injected in the kaolinite column and $CH_3$COOH was continuously added to the cathode reservoir to restrain the pH increase. The pH of the cathode of the kaolinite column was 4.0 at first. Since it was controlled to be under 6.5 after 43.6 hours due to ethanoic buffer, precipitation of ${Co(OH)}_2$ was not formed in the column. Effluent rate increased with time and $Co^{2+}$ removal in the column at initial time was mainly controlled by ion migration. 13.1% of total $Co^{2+}$ in the column was removed after 10 hours, the 46.8% of total $Co^{2+}$ after 20.8 hours, and the 71.7% of total $Co^{2+}$ after 30.1 hours, the 94.6% of total $Co^{2+}$ after 43.6 hours, Meanwhile, the residual concentrations in the column calculated by the developed model were similar to experiment results.

• Economic and Environmental Geology
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• v.30 no.2
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• pp.89-103
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• 1997

The purpose of this research is to investigate the enrichment and distribution patterns of naturally occurring potentially toxic elements in soils derived from black shales and slates. Soil samples were collected from the Chubu area covered with uranium-enriched black shales and slates of the Changri Formation of the Okchon Super Group, and analysed for multiple-elements using INAA, ICP-AES and AAS. Soil pH and loss-an-ignition were also measured. Trace element contents in black shale and slate of the Chubu area are relatively lower than those in black shales, and higher than those in black slates reported elsewhere (Chon, Jung, 1991; Chon et al., 1996). Soil pH values range from 3.5 to 6.5, and loss-an-ignition values are in the range from 3 to 10%. Potentially toxic elements including As, Ba, Cr, Cu, Mo and U are highly enriched in residual soils with maximum content of $540{\mu}g/g$, $35,000{\mu}g/g$, $280{\mu}g/g$, $300{\mu}g/g$, $240{\mu}g/g$ and $860{\mu}g/g$, respectively. Significant concentrations of those elements were found in soils taken from the Tojangkol, the Chubu tunnel and the Meokti areas. Soils derived from black shales and slates, calcareous and phyllitic rocks, and intrusions were discriminated in terms of As, Ba, Co, Cr, Cu, Mo, Sc and U contents. Enrichment index was calculated using the concentrations of As, Ba, Cr and Mo, and enrichment index map shows very similar trend with U distribution in soils.

• The Journal of Engineering Geology
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• v.10 no.2
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• pp.189-214
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• 2000

Three study areas of Kwanak campus(Seoul National University), Gapyung and Boeun were selected and classified according to bedrock types in order to investigate soil-gas radon concentrations. Several soil-gas samples showed relatively high radon concentrations in the residual soils which derived from granite bedrock. It also showed that water content of soil and the degree of radioactivity disequilibrium was a secondary factor governing radon emanation and distribution of radon radioactivity. The results of radon concentrations and working levels for forty rooms in Kwanak campus, Seoul National University, showed that indoor basement rooms under poor ventilation condition can be classified as high radon risk zone having more than EPA guideline(4 pCi/L). Some results of section analysis which was surveyed in the fault zone of Kyungju and Gapyung area confirmed the existence of fault-associated radon anomalies with a meaning of radon risk zone.

• Journal of Environmental Science International
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• v.14 no.6
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• pp.583-596
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• 2005

Samples of water, soil, and sediment were taken from 10 streams of Andong city in Gyeongbuk province in October 2004. To assess the degree of environmental pollution for each stream site, the chemical analyses of pollutants such as T-N, T-P, COD, heavy metal, organophosphorous and organochlorine pesticides, and dioxin-like PCB congeners were implemented using the standard process tests or the U. S. EPA methods. In addition, biological assessment using insect immune biomarkers was conducted on the same environmental samples to complement the chemical assessment. Except Waya stream (T-N; 2.91 mg/L, T-P; 0.16 mg/L, COD; 14.0 mg/L) with above the environmental quality standards, the T-P and COD concentrations of 9 sites are relatively low. The contents of Pb and Cd in samples taken from each stream were much lower than environmental quality standards. However, in comparison with soil samples of other streams, several times higher concentrations of Pb and Cd were found in locations at Mi, Gilan, Yeonha, and Waya stream sites. Dementon-S-methyl, diazinon, parathion, and phenthoate compounds among organophosphorous pesticides were detected as concentrations of ppb levels, respectively, from soil samples collected in the vicinity of Gilan, Mi, Norim, and Waya stream. On the other hand, 16 organochlorine pesticides and 12 dioxin-like PCB congeners selected in this study were not found in all samples. In particular, considering significant disrupting effects of Waya stream's samples on insect immune capacity, this stream seems to be contaminated with investigated and/or univestigated pollutants in this study.