• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.3
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• pp.77-91
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• 2015

This study aims to suggest adequate soil management through the analysis of physicochemical properties of soil in the planting grounds of Incheon International Airport, which was constructed on a massive land reclamation site. Study areas were 5 sites at the international business complex, the passenger terminal, the airport support complex, the free trade zone, and the access road. Soil profile analysis showed that 9 plots out of the 27 plots were hardpan and heterospere within 80cm from the soil surface. The earth laid on the ground was categorized as gravel based soil(4 plots), dredged soil from the sea bottom and mixed reclamation materials(2 plots), clay with poor permeability(3 plots) and waste construction material(1 plot). Average soil hardness was $11.5kg/cm^2$ and soil textures were sandy soil, sandy loam and loamy sand. Average soil pH was 6.7 and average organic matter content was 0.7%. Electrical conductivity was 0.0dS/m and exchangeable cation concentrations were $Ca^{2+}$ 3.4cmol/kg, $Mg^{2+}$ 1.5cmol/kg, $K^+$ 0.3cmol/kg and $Na^+$ 1.0cmol/kg. Average cation exchange capacity was 11.0cmol/kg. Although average figures in Solum mostly meet the landscape design criteria, properties of each soil layer showed various values sometimes over the limit. Base saturations were $Ca^{2+}$ 29.9%, $Mg^{2+}$ 13.3% and $K^+$ 3.7% for lower soil, $Ca^{2+}$ 33.3%, $Mg^{2+}$ 17.0% and $K^+$ 2.7% for mid-soil and $Ca^{2+}$ 32.6%, $Mg^{2+}$ 12.2% and $K^+$ 1.9% for upper soil. Exchangeable sodium percentages were 16.4% for lower soil, 7.5% for mid-soil and 4.7% upper soil. Sodium adsorption rates were 0.8 for lower soil, 0.3 for mid-soil and 0.2 for upper soil. Factors affecting to the vegetation growth were heterogeneity and poorness of solum, disturbance of dredged soils, high soil hardness including hardpan in the subsurface soil layer and shallow effective soil depth, high soil acidity, imbalance of base contents, low organic matter content and low available phosphate levels in the soil.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.10a
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• pp.440-447
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• 2000

In order to evaluate the cost effectiveness of seismic isolation for bridges in low and moderate seismic region, a method of calculation minimum life-cycle cost of seismic-isolated bridges under specific acceleration level and soil condition is developed. Input ground motion is modeled as spectral density function compatible with response spectrum for combination of acceleration coefficient and site coefficient. Failure probability is calculated by spectrum analysis based on random vibration theories to simplify repetitive calculations in the minimization procedure. Ductility of piers and its effects on cost effectiveness are considered by stochastic linearization method. Cost function and cost effectiveness index are defined by taking into consideration the characteristics of seismic isolated bridges. Limit states for calculation of failure probability are defined on superstructure, isolator and pier, respectively. The results of example design and analysis show that seismic isolation is more cost-effective in low and moderate seismic region than in high seismic region.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.841-846
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• 2003

The purpose of this paper is to present and discuss some of harbor foundation constructed on seashore soft ground by Deep Wing Mixing in deep mixing method. A series of laboratory and field experiments including unconfined compressive strength, permeability, geo-physical survey, sea water concentration, lateral and settlement measurement, field core sample were carried out to check physical, mechanical and environmental characteristics of solidified foundation soil treated by HWS solidifying agent. The results from this research showed that Deep Wing Mixing method could be efficiently applied in the construction site of seashore structure foundation.

• Journal of Industrial Technology
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• v.25 no.B
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• pp.27-35
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• 2005

Non-point source pollution, which is found in soil, urban area, and agricultural area, is difficult to have its amount to be estimated. Moreover, it is hard to come up with a counterplan to cope with this pollutant. Hence, the watershed of Mandae-cheon located at the upstream of Soyang Lake was chosen as our site of study. We analyzed the relationship between precipitation level of each month and pollution load in the watershed by using statistical methods: measuring BOD, T-N and T-P - which are the causes of eutrophication - in the water; and analyzing the changes in water quality caused by precipitation level of nth.

• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.77-83
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• 2002

A bacterial consortium capable of utilizing a variety of polycyclic aromatic hydrocarbons has been isolated from a former manufactured gas plant site. The consortium consisted of four members including Arthrobacter sp., Burkholderia sp., Ochrobacterium sp., and Alcaligenes sp., which were identified and characterized by the patterns of fatty acid methyl esters (FAME analysis) and carbon source utilization (BIOLOG system). With the individual members, the biodegradation characteristics of aromatic hydrocarbons depending on different growth substrates were determined. FAME analyses demonstrated that microbial fatty acid profiles changed to significant extents in response to different carbon sources, and hence, such shift profiles may be informative to characterize the biodegradation potential of a bacterium or microbial community.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.940-945
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• 2010

There are human casualties that caused by slope-stability related disasters such as landslide and debris flow during typhoon and rainy season every year in Korea. These disaster sites can be analyzed systematically using digital topographic data and aerial photogrammetry. In this study, geographical factors such as slope degree, geology, height, and soil depth are analyzed in four landslide-disaster sites from Muju, Jinan, and Jangsu County based on digital elevation maps generated by ArcGIS. Each site showed different characteristics in geology and geography and it is found that GIS can be utilized for the visualization of steep-slope failure areas.

• Structural Engineering and Mechanics
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• v.31 no.1
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• pp.93-112
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• 2009

In this study seismic analyses of steel structures were carried out to examine the effect of ground motion characteristics and structural properties on energy demands using 100 earthquake ground motions recorded in different soil conditions, and the results were compared with those of previous works. Analysis results show that ductility ratios and the site conditions have significant influence on input energy. The ratio of hysteretic to input energy is considerably influenced by the ductility ratio and the strong motion duration. It is also observed that as the predominant periods of the input energy spectra are significantly larger than those of acceleration response spectra used in the strength design, the strength demand on a structure designed based on energy should be checked especially in short period structures. For that reason framed structures with buckling-restrained-braces (BRBs) were designed in such a way that all the input energy was dissipated by the hysteretic energy of the BRBs, and the results were compared with those designed by conventional strength-based design procedure.

• Geotechnical Engineering
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• v.13 no.5
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• pp.125-132
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• 1997

It is observed that debris mitred with a wide range of soil particles and water moves downwards like viscous fluid soon after a landslide has triggered. An Assumption can be made from the field observation that the debris flow behaves as a kind of non(non-Newtoniron) Newtonian fluid which has non linear viscosity. In this study, a series of viscosity tests are carried out to measure rheological properties of debris by using a viscometer with semples taken from a landslide site. It is proved that debris flows behave as Bingham plastic mod el of non-Newtonian fluid. This model can be used predict the movement of debris flows.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.10a
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• pp.241-248
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• 1999

Structural damage during an earthquake is caused by the response of the structure to the ground motion input at its base. The dynamic force produced in the structure are due to the inertia of its vibrating elements. The response of the structure exceeds the ground motion and this dynamic magnification depends on the duration and frequency content of the ground vibration, the soil properties at the site, distance from the epicenter and the dynamic characteristics of the structure. Earthquake load used in this study as a input data was artificially simulated with the design spectrum diagram in the Korean Earthquake Resistant Design Code. This paper presents the seismic analysis of the continuous preflex composite girder bridges according to variation of pier's height and span's length.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.197-199
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• 2011

To utilize the Top-Down construction method, it is required to analyse building area, floors, and soil conditions to choose the three basic elements of retaining wall, base column, and floor structure. The purpose of this research is to compare the methods of Top-Down with other construction methods. The research method is to analyse the project conditions of Top-Down project cases. The aim is to develop a method of selecting alternatives, considering construction characteristics, work schedule, supporting methods, foundation types.