• Journal of the Korean Geotechnical Society
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• v.28 no.12
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• pp.27-39
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• 2012

This paper presented the strength and environmental characteristics of reclaimed-ground filled with controlled low-strength materials (CLSM) made of coal ash, small amounts of cement, and water in a reclamation site and evaluated the possibility of the use of coal ash on reclamation materials for beneficial use. Three-month period of SPT, CPT, environmental effects evaluation etc. were conducted. N values and cone resistances in ground filled with CLSM were greater than or similar to those in dredging sand. In case of land filled with coal ash except cement these values were lower than those in dredging sand. The results of soil and seawater pollution were lower than test criteria without high pH. Also the values of PH test were measured between pH 5.0~9.0, the criteria of industrial water in the Law for the Underground Water of Korea.

• Journal of Navigation and Port Research
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• v.43 no.2
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• pp.79-85
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• 2019

Climate change is a very vital issue that can be no longer avoided. Korea has been a top-level country Iin dealing with carbon dioxide emissions since 1960. Many studies have been conducted to suppress or eliminate carbon dioxide emissions, which account for a large portion of greenhouse gases. Carbon Capture and Storage (CCS), the most practical method of them, plays a significant role. However, these methods have the disadvantage of the limits of geographical distribution and high possibility of re-emission into the atmosphere. Recently, ocean storage has been studied using Accelerated Weathering of Limestone (AWL), a technique for storing carbon dioxide in the ocean as an alternative to CCS, an underground storage. AWL is a method of converting carbon dioxide into concentrated water in the form of bicarbonate ion and discharging it to the ocean to dilute and store it. It does not cause re-emission to the atmosphere, and the discharged concentrated water increases the alkalinity of the ocean to prevent marine acidification. The objective of this study was to understand the behavior of DIC (Dissolved Inorganic Carbon) including carbon dioxide during the ocean discharge of bicarbonate ion concentrated water in AWL method. This study area was set near Ulleung-do where sufficient water depth and operational efficiency were secured. CORMIX model was used to calculate the material diffusion by submerged discharge using ship.

• Ecology and Resilient Infrastructure
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• v.9 no.4
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• pp.247-258
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• 2022

Hampyeong Bay has a narrow seawater channel and a complex topographical structure. The sand content of the tidal flat soil is increasing due to asymmetrical sedimentation. Through the investigation of the vegetation distribution and the use of the line-transect method, sand flats were observed to gradually change the vegetation distribution of salt marshes. Comparing the vegetation area between 2016 and 2022, the obligate halophyte Suaeda maritima decreased by 74% and Zoysia sinica increased by 75%. Z. sinica seems to support the robustness of the dune environment by trapping sediments such as sand in the colony, because the underground rhizomes and stems are highly developed. To establish an effective conservation management plan for tidal flats, an integrated study should be conducted to assess the impact of changes in tidal flat soil and the interaction of vegetation communities in Hampyeong Bay.

• The Journal of Engineering Geology
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• v.8 no.1
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• pp.51-73
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• 1998

Hydrogeological systems in a metrnpolitan area can be understood by analyzing the groundwater disturbing factors such as constructions and land applications, the groundwater usage for domestic and industrial purposes, and the groundwater pumpage to lower the groundwater level for the structural safety of subway and underground facilities. This study is part of the study performed to understand the groundwater system in the Seoul area and it is focusing on the hydraulic properties. Groundwater well inventory, barometric efficiency measurements, pumping and slug tests, and long-term groundwater monitoring have been perfonrmed during the last 2 years. The relations between Han River and the groundwater around the river also have been observed. These observations and test data, together with the information on soil distribution, geology, and logging data are used to construct a database and GIS(Geographic Information System) presentation system using ARC/INFO. Barometric efficiencies appeared to have no special trends associated with well depths, which maeans that the degree of confinement of the crystaline rock aquifer of the Seoul area is distributed locally depending on the developrnent of fractures. Hydraulic conductivities exponentialiy decrease with well depth. The stage of Han River fluctuates according to the tidal movement of nearby seawater but the tidal effects attenuate due to the underwater dams. Groundwater levels in the Seoul area seem to have declined for the last two years,but it is not certain that the declination represents the long-term trend.