• Proceedings of the Korean Geotechical Society Conference
• /
• 2004.03b
• /
• pp.491-498
• /
• 2004

In recent years, as an effort to grasp the leading position in the field of maritime trading, new ports and container terminals arc now under construction. Old ports are extended. At the beginning, stones were thrown down to form stone embankments, that is stone-dams, in the outer and inner boundaries of the planned reclamation-land. S.C.P(Sand Compaction Pile) works are often needed to improve the stability of stone-dams, where marine sediments arc relatively thick. Here, interests are centered on the shape of stone body. In this, drilling work won't provide a sufficient resolution. In addition, the result corresponds to only one borehole point information. Thus, the aim of this paper is to introduce an affordable technology, that is, a combined geophysical method(seismic tomography + Televiewer) enables to get the whole information about stone-dam section. The measuring and evaluating procedure is described in detail with an emphasis on dealing with the use of seismic detonator, proper borehole deployment and integrated data analysis. Examples of field experiments at Busan new port are illustrated, which will prove the benefit of combined geophysical method.

• Journal of Korean Society of Water and Wastewater
• /
• v.28 no.5
• /
• pp.589-600
• /
• 2014

Tuberculation and slime accumulated in water mains play an important role in modifying water quality of drinking water. Therefore, in this study, it was investigated that what materials were accumulated, and what components were included in the tuberculation and slime of water mains. The Various tuberculation and slime sample were collected from the 12 water mains to analyze their physical and chemical properties and crystal structure. As a analysis method, VSS(Volatile suspended solid), SEM(scanning electron microscope), EDS(Energy Dispersive X-ray spectroscope), ICP(Inductively Coupled Plasma Mass Spectrometer) and XRD(X-Ray Diffractomete) were used. The results of analysis on the samples, the representative materials were verified such as iron corrosion products, the fine sand particles generated during backwash, fine particles of activated carbon, aluminum used in coagulation process, and manganese included in raw water.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.09a
• /
• pp.1164-1169
• /
• 2009

Piled raft foundation is commonly used for structure on deep soft soil deposit rather than end bearing piles to control differential settlement. However, it is still expensive for light weight structures. Wing-wall type foundation has been successfully applied to reduce average settlement for light weight structure. This study will further investigate this type of foundation using bench scale experiments on clay and sand. Numerical analysis and approach method are used to verify load settlement curve of wing-wall foundation on experimentally study. Furthermore, normalized settlement curves are applied to define prediction of settlement on wing-wall foundation. In the result settlement on wing-wall foundation can be effectively done by increasing the length of wall instead of number of walls and equation for calculating average settlement can be derived using normalized load settlement curve.

• Journal of Navigation and Port Research
• /
• v.33 no.2
• /
• pp.119-125
• /
• 2009

The effect of plastic board drains (PBDs)on ground improvement was checked out considering three crucial factors: ground settlement, undrained shear strength, and residual water head. First, the settlement analysis including initial settlement induced by reclamation of sand mat was conducted by back calculation analysis with measured data. Its result showed toot the PBDs used for this site worked well on improving soft ground. Secondly, the undrained shear strength was investigated by laboratory and in-situ tests including unconsolidated-undrained triaxial compression (UU) tests, unconfined compression tests, in-situ vane tests, and cone penetration tests. From the test results, they showed that the undrained shear strength of the improved ground by PBDs was significantly increased as well as the strength increasing ratio especially $10{\sim}15m$ below the ground surface on site. Thirdly, the residual water head measurement from the in situ dissipation test was found the same as the static water head, which indicated primary consolidation was completed and the effect of soil improvement with PBDs can be confirmed.

• The Journal of Engineering Geology
• /
• v.17 no.3
• /
• pp.471-481
• /
• 2007

The Landslide in natural slope is occurred mostly by a heavy rain of the summer. This landslide is influenced in soil property of the surface than the rock mass. Soils in natural slope are created by weathering phenomena of the bedrock. These soils differed to the geological conditions such as sedimentary rock, metamorphic rock and volcanic rock. Therefore, estimation of landslide in natural slope is the most important analysis of the bedrock distributions and soil characteristics. This study analyzed the soil property to the natural slopes of Busan area where is distributed to volcanic rock, granite and sedimentary rock. Soil sample conducted various soil tests for estimate the soil physical property and soil engineering characteristics, and analysis of the correlation of geological conditions. In the experiment result, soils were mainly classified by a clayey sand. It is also established that $1.07{\sim}1.99kg/cm^3$ for wet density, $28.2{\sim}39.6^{\circ}$ for angle of shearing resistance, and $8.10{\times}10^{-5}{\sim}8.38{\times}10^{-2}cm/sec$ for coefficient of permeability. From the physical parameter, the soils are estimated to the permeable ground with good shear strength, and soil properties are showed a differential tendency for each geological condition.

• Journal of Korean Society of Environmental Engineers
• /
• v.28 no.12
• /
• pp.1274-1279
• /
• 2006

The formation characteristics of $BDOC_{rapid}$ and $BDOC_{slow}$ with different ozone dosages for 3 different kinds of waters from Maeri raw water in the down stream of Nakdong river, Hoidong reservoir water in Busan City and treated Maeri raw water(sand filtered) has been investigated in this study. The ozone dosages for producing maximum $BDOC_{total}$ in the Maeri raw water, Hoidong reservoir water and sand filtered water of Maeri were 0.9, 1.1 and 1.4 $mgO_3$/mgDOC respectively. It could be concluded that the ozone dosages for formations of maximum $BDOC_{total}$ were determined by characteristics of water. The ozone dosages for producing maximum $BDOC_{rapid}$ in the Maeri raw water, Hoidong reservoir water and sand filtered water of Maeri were 0.9, 0.9 and 1.0 $mgO_3$/mgDOC respectively that were same or lower than the used ozone dosages for producing maximum $BDOC_{total}$. $BDOC_{slow}$ was being formated and increased continuously with the higher ozone dosages which were the used ozone dosages for maximum formation of $BDOC_{total}$ and $BDOC_{rapid}$. For the best results of a pre-treatment of biofiltration, the optimum ozone dosage ranges in formation of $BDOC_{rapid}/BDOC_{total}$ were $0.6{\sim}1.0\;mgO_3$/mgDOC that were lower than the ozone dosage ranges of $0.9{\sim}1.4\;mgO_3$/mgDOC for the maximum formation $BDOC_{total}$. The reported results indicated that the best and effective ways from economic and technical points of view to determine the optimum ozone dosages of the pretreatment of biofilteration process were investigating and classifying BDOC.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.2
• /
• pp.285-292
• /
• 2011

In order to develop livestock wastewater treatment technology by natural purification method, the optimum filter media in small-scale livestock wastewater treatment apparatus for treating livestock wastewater were studied. Removal rates of pollutants under different filter media were in the other of coarse sand ${\fallingdotseq}$ broken stone > zeolite > calcite for COD, zeolite >> broken stone ${\fallingdotseq}$ coarse sand ${\fallingdotseq}$ calcite for T-N, and calcite > coarse sand ${\fallingdotseq}$ broken stone ${\fallingdotseq}$ zeolite for T-P. Based on the above results, the optimum filter media was coarse sand in small-scale livestock wastewater treatment apparatus. To meet acceptable effluent quality standard for livestock wastewater and to improve T-N and T-P removal efficiencies, removal efficiencies of pollutants in small-scale livestock wastewater treatment apparatus with mixed filter media were studied. The removal rates of COD, SS, T-N and T-P in effluent were 84, 94, 65 and 98% in small-scale livestock wastewater treatment apparatus with mixed filter media, respectively. For increasing the T-N and T-P removals in small-scale livestock wastewater treatment apparatus, the mixed filter media are recommended.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.17 no.2
• /
• pp.61-69
• /
• 2005

The coastal erosion and the look of a heap which are mainly occurred in the district along the coast are found for various forms such as the estuary closing, the estuary sand bar the development of the coast sand bar, and the modification of coastline. Recently, due to the coastal development, these transformations have been intensified. The change of coast, which has been made slow progress is required long-term study on a searching examination of the root cause and a suggestion of a counter measure. In this research, ortho aerial photos were produced to analyze volumes of topographical alternations that have been progressed fer the long run, by 10s cycle from 1940s through 1990s, to compute accurate volumes of coastline variation, through a datum point and G.C.P (Ground Control Point). Also in this study, without respect to water level, the coastline variation was analyzed by using comparatively analyzed a Idlest land map, a cadastral map. And to analyze topographical variation volumes, the tidal station's materials was used under consideration f3r tide. Finally, topographical variation volumes are comparatively analyzed through surveying and sounding and a point of fine of aviation photographing was calculated and revised. After this research, by using ortho aerial photos, We can understand efficiency of these in computing volumes of variations of coastline by analyzing quantitatively erosion and look of a heap. Besides, in the future, these will be used for information gathering of the coastline integration control system.

• Journal of the Korean GEO-environmental Society
• /
• v.4 no.2
• /
• pp.65-76
• /
• 2003

Stone column is a soil improvement method and can be applicable for loose sand or weak cohesive soil. Since the lack of sand, stone column seems one of the most adaptable approach for poor ground as a soil improvement technique. However, this method was not studied for practical application. In this paper, the bearing capacity of single stone column at the Gaduk, Ulsan and Gwangyang under the bulging and general shear failure mode were compared with those of the suggested formulas. Especially, a test result of single stone column at the Busan area by static load was compared with the bearing capacity of suggested formulas. The analysis results showed that there were not much bearing capacity differences among those suggested bearing capacity formulas. However, the bearing capacity by static load test was almost double of those with suggested formula. The result also showed that the undrained shear strength was the most important parameter for the bearing capacity estimation of stone column.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.3
• /
• pp.393-399
• /
• 2003

The purpose of this study was to investigate the preferred methods for making summer kimchi as a basic research of making commercial kimchi. Questionnaire were collected from 590 housewives nationwide in Korea, and the data were analyzed by SPSS program. The results were as follows: (1) The average salting time of Chinese cabbage was 3~5 hrs when the combined method of dry and brine salting was used, regardless of the region. (2) Seven jeotkals (salt-fermented fishes) including anchovy, anchovy juice, shrimp, northern sand lance juice, hair-tail viscera, flatfish and yellow corvenia were mainly used in kimchi. Among them, anchovy and anchovy juice jeotkals were preferred to all others in Southern area (Busan, Gwangju, Gyeongnam, Gyeongbuk, Jeonnam), while shrimp jeotkal in Seoul, Gwangju, Jeonbuk, Chungnam and Jeju, and northern sand lance juice jeotkal in Daegu, Daejeon and Gyeonggi, respectively. In most regions, however, blending type of 2 jeotkals was used in kimchi. (3) Eleven ingredients such as red pepper, garlic, ginger, green onion, radish, leek, onion, carrot, sugar, sesame and MSG were used as basic components for making kimchi. In particular, MSG was used as a basic ingredient regardless of region and age. However, a standard taste for making kimchi was depended on housewife in this study.