• Journal of Soil and Groundwater Environment
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• v.10 no.6
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• pp.1-9
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• 2005

Soil is polluted by an agricultural chemicals, the effluence of a crystal and sewage sludge, illegal discharging of waste water or waste matter and so on. Soil pollution that accompanies a groundwater and the crops contamination has a large effect on people's living. By polluters pay principle, when a soil was polluted, polluters take the responsibility of clean-up and compensation for damages. The character of the responsibility is a strict liability. When joint polluters exist in a soil pollution, they bear collective responsibility. But they are exempted from obligation in case of a natural calamity and war. The polluters who are poor contribution of pollution take a partition responsibility but it is not easy to prove that. The concerned parties of purification liability in a soil pollution are polluter, an owner or occupant of a contaminated site, and a grantee. But when we do not appoint the polluter or he cannot do a cleanup, municipal must put in effect the purification. In such a case, another parties who are related to the contamination should take upon themselves a liability. The province of responsible parties, therefore, is required to extend to an owner or operator of a facility, a carrier and lender.

• Journal of the Korean Geotechnical Society
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• v.34 no.6
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• pp.61-73
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• 2018

When the shear deformation occurs on the slope reinforced with soil nail, a passive earth pressure is induced on the ground around the soil nail and the increase of shear deformation causes the earth pressure variation of the ground and the deformation and member force change of the soil nail. In this study, the shear behavior of the soil nail was analyzed experimentally by inducing the shear deformation in the vertical direction of the soil nail using a large-scale direct shear test equipment and it was verified through numerical analysis. The shear test was performed on the bonded length (6D, 8D, 10D and 12D) of the soil nail separated from the shear surface. As a result, it was observed that the continuous increase of the shear deformation caused the damage of the grout and the effect according to the bonded length was analyzed. Through the model test and the numerical analysis, it was confirmed that the transfer length of the soil nail was 0.2~0.22m, which is larger than 0.1m suggested in the previous study, and the shear zone was in the range of 0.6m from the shear surface.

• Korean Journal of Soil Science and Fertilizer
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• v.51 no.2
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• pp.90-100
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• 2018

Environmental pollution with arsenic (As) in croplands causes agricultural and health problems worldwide. Rice is an important crop in South Korea, and many studies have evaluated the relationship between As and glutathione (GSH) to alleviate As uptake from the soil into plants. However, information about the relationship between As and ascorbate (AsA) in rice seedlings is still limited with regard to As phytotoxicity. We therefore investigated changes in reactive oxygen species (ROS) and antioxidant levels in rice (Oryza sativa L. cv 'Dasan') seedlings with toxic As and/or AsA application. The exposure of rice seedlings to $15{\mu}M$ As inhibited plant growth and resulted in increased contents of superoxide, hydrogen peroxide, and malondialdehyde, and induced As uptake by the roots and leaves. Application of AsA to As-exposed seedlings ameliorated As-induced oxidative stress by enhancing the capacity of AsA-GSH cycle in applied plants and increasing As transfer from the roots to leaves. These results suggest that AsA application alleviated As-induced oxidative damage by maintaining sufficient levels of AsA and GSH.

• Journal of the Korean GEO-environmental Society
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• v.8 no.4
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• pp.67-74
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• 2007

Many studies for slope stability studies have indicated that the infiltration of rainwater into a slope decrease the slope stability. In order to minimize damage caused by slope failure, most design codes suggest that the slope stability be analyzed by saturated condition during rainy season. However it would be excessively conservative condition that every soil slope is saturated in rainy season irrespective of rainfall intensity, soil type and slope geometry. In addition, because most soil slopes are in an unsaturated state, it is necessary to consider the unsaturated characteristics of slope. This paper suggests a prediction method of saturation time for the weathered granite soil slopes due to rainfalls. The finite element analysis of transient water flow through unsaturated slope was used to investigate effects of soil-water characteristics, permeability at saturation, slope geometry, and rainfall intensity. From the result of these analyses, the prediction charts considering soil-water characteristics, permeability at saturation, and slope height were proposed in this study. It is possible to the time required to be saturated slope after rainfall.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.2
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• pp.129-135
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• 2013

This study was conducted to investigate the soil characteristics of newly reclaimed tidal land and the effect of green manure crops on soil properties. Summer green manure crops such as sesbania (Sesbania grandiflora), barnyard grass (Echinochloa spp.) and sorghum${\times}$sudangrass hybrid (Sorghum bicolor L.) were cultivated at Hwaong, Ewon, Saemangeum and Yongsangang area. Soil pH of reclaimed tidal land was relatively high, but organic matter and available phosphorus contents were lower compared to the optimum range for common upland crops. Soil nutrient contents were unbalanced for upland crop growth. Yield of green manure crops had a wide spatial variation. Nitrogen content in green manure crops was the greater in Sesbania and it was estimated that major nutrient ($N-P_2O_5-K_2O$) supply amount were 150-40-370, 220-50-170 and 140-50-250 $kg\;ha^{-1}$ from sorghum${\times}$sudangrass hybrid, sesbania and barnyard grass, respectively. Based on these results, desalination is required to grow the upland crops at newly reclaimed tidal lands and management practices are necessary to reduce the salt damage by resalinization during the growing seasons. To improve the productivity and increase the nutrient utilization rate, soil physicochemical properties need to be improved to the level for upland crops by application of organic matter and fertilizer.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.4
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• pp.305-311
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• 2015

Both low and high temperatures affect plant growth and development at whole plant level, tissue and even cell level through a variety of metabolic changes. Temperature stress is one of frequently occurring problems in greenhouse crops in summer and winter seasons due to the wide-spread year-round cultivation. In the present study, we investigated the extent of the inhibition of growth, macro-element uptake and soluble carbohydrate production, and the effect of extra-supply of minerals as a means of the recovery from temperature damage. Tomato plants were grown five different growth temperatures (15/8, 20/13, 28/21, 33/23 and $36/26^{\circ}C$), and extra-supply of minerals was composed of 1.5- and 2.0-fold stronger than the standard nutrition (1/2 strength of Hoagland's solution). Temperature stress significantly adversely affected tomato growth and mineral uptake, whereas soluble carbohydrate accumulation represented temperature-dependent response, more accumulation at low temperature and more consumption at high temperature. The soluble sugars in leaves and stems were mostly declined with the supply of extra-minerals at low and optimal temperatures, whereas remained unchanged at high temperature. The starch levels also remained unchanged or slightly decreased.

• Corrosion Science and Technology
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• v.4 no.5
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• pp.178-190
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• 2005

In order to develop a new corrosion sensor for detecting and monitoring the external and internal corrosion damage of buried pipeline, the electrochemical property of sensors and the correlation of its output to corrosion rate of steel pipe, were evaluated by electrochemical methods in two soils of varying resistivity (5,000 ohm-cm, 10,000 ohm-cm) and synthetic tap water environments. In this paper, two types of galvanic probes were manufactured: copper-pipeline steel (Cu-CS) and stainless steel-pipeline steel (SS-CS). The corrosion behavior in synthetic groundwater and synthetic tap water for the different electrodes was investigated by potentiodynamic test. The comparison of the sensor output and corrosion rates revealed that a linear relationship was found between the probe current and the corrosion rates. In the soil resistivity of $5,000{\Omega}-cm$ and tap water environments, only the Cu-CS probe had a good linear quantitative relationship between the sensor output current and the corrosion rate of pipeline steel. In the case of $10,000{\Omega}-cm$, although the SS-CS probe showed a better linear correlation than that of Cu-CS probe, the Cu-CS probe is more suitable than SS-CS probe due to the high current output.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.778-782
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• 1997

Effects of different water potential on the growth and aerenchyma development of Adlay(Coix lacryma-jobi L. var. mayuen) were studied under every 3 days intermittent irrigation as a control at different growth stages, flooded pot condition and drought. Adlay could not germinate in the anaerobic soil conditions with excessive moisture while it wasn't inflicted with moisture damage after sprouting. Sprouted adlay can grow under flooded soil moisture condition because it's root has orthostichy cell, ventilating structure and cortex. Proping or ventilating roots were generated from adlay grown under flooded pots. Drought damage inflicted at the heading stage was the most severe.

• Earthquakes and Structures
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• v.21 no.6
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• pp.641-652
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• 2021

Digging well foundation has been widely used in railway bridges due to its good economy and reliability. In other instances, bridges with digging well foundation still have damage risks during earthquakes. In this study, a new type of digging well foundation with prefabricated roots was proposed to reduce earthquake damage of these bridges. Quasi-static tests were conducted to investigate the failure mechanism of the root digging well foundation, and then to analyze seismic behaviors of the new type well foundation. The testing results indicated that these prefabricated roots could effectively limit the rotation and uplift of the digging well foundation and increase the lateral bearing capacity of the digging well foundation. The elastic critical load and ultimate load can be increased by 69% and 36% if prefabricated roots were added in the digging well foundation. The prefabricated roots drived more soil around the foundation to participate in working, the stiffness of the bridge pier with root digging well foundation was improved. Moreover, the root participation could improve the energy dissipation capacity of soil-foundation-pier interaction system. The conclusions obtained in this paper had important guiding significance for the popularization and application of the digging well foundation with prefabricated roots in earthquake-prone zones.

• Structural Engineering and Mechanics
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• v.88 no.1
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• pp.13-23
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• 2023

Seismic risk assessment studies are one of the most crucial instruments for mitigating casualties and economic losses. This work utilizes fragility curves to evaluate the seismic risk of single-story precast buildings, which are generally favored in Marmara's organized industrial zones. First, the precast building stock in the region has been categorized into nine sub-classes. Then, seven locations in the Marmara region with a high concentration of industrial activities are considered. Probabilistic seismic hazard assessments were conducted for both the soil-dependent and soil-independent scenarios. Subsequently, damage analysis was performed based on the structural capacity and mean fragility curves. Considering four different consequence models, 630 sub-class-specific loss curves for buildings were obtained. In the current study, it has been determined that the consequence model has a significant impact on the loss curves, hence, average loss curves were computed for each case investigated. In light of the acquired results, it was found that the loss ratio values obtained at different locations within the same region show significant variation. In addition, it was observed that the structural damage states change from serviceable to repairable or repairable to unrepairable. Within the scope of the study, 126 average loss functions were presented that could be easily used by non-experts in earthquake engineering, regardless of structural analysis. These functions, which offer loss ratios for varying hazard levels, are valuable outputs that allow preliminary risk assessment in the region and yield sensible outcomes for insurance activities.