• Journal of the Korean Geosynthetics Society
• /
• v.19 no.4
• /
• pp.75-84
• /
• 2020

This paper described the analysis result on heaving of soft ground with DCM column type, based on the results of laboratory model tests on the soft ground with DCM column. The heave characteristics of the soft ground were evaluated according to the application of DCM column in soft ground. The results showed that the heaving of soft ground without DCM column occurred rapidly when the lateral deformation of soft ground increased significantly under the 4th load step condition. In addition, the heaving of soft ground in final load step caused tensile failure of the ground surface. The maximum heaving of the soft ground with the DCM column occurred in the final load step, and the heaving quantity decreased in the order of pile, wall, and grid type. Especially, the soft ground with DCM of grid type effectively resisted ground heaving, even if it was extremely failure in the bottom ground of embankment. The results of the maximum heaving according to the measurement point showed that the heaving of the soft ground with DCM of grid type was 3.1% and 1.6% compared to that of the pile and wall type at the location of LVDT-1, and the heaving of the LVDT-2 position was 1.0% and 2.1%, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.11 no.1
• /
• pp.145-151
• /
• 1991

The final purpose of this study is to examine the uses of coal ash, by-product from thermal power plant as a type of filling-embankment materials and the reuses of ash ponds. In this time, to investigate the dynamic properties, we made the test piece specimen with coal ashes, and obtained the damping ratio. In place(ash pond), the damping property by underground wall was investigated before and after soil improvements. The damping ratio of coal ash test piece specimen of 12% cement is the highest and that of 9% cement or chemical grout, that of 6% cement is in order. In same coal ash test piece, the damping ratio increases with decreasing the void ratio. In conclusion, it could be said that the damping ratio increases with the stiffness of materials. In the ash pond, the damping effect is the most when trench is set through the vibration wave propagation course, and when soil is improved the higher stiffness of the improved soil is, the more damping effect appeared. It is justified to obtain not only the dropping of permeability and the strength increase, but also the damping effect fairly by soil improvements.

• Microbiology and Biotechnology Letters
• /
• v.18 no.6
• /
• pp.560-565
• /
• 1990

When protoplasts from auxotrophie mutant of Trkhoderma koningii CUT121(Lys-, Met-) were mixed with isolated nuclei of wild type T. koningii ATCC 261 13 and treated with PEG solution, protrophic colonies were produced with frequency of more than 30 percent. One of segregants from prototrophic colonies showed increased xylanase activity and other polysaccharide-hydrolyzing activities comparable to those of wild type strain. Through measurement of DNA contents, induced segregation, and analysis of isozyme patterns, it was revealed that the prototrophic colonies were transformants resulted from exchange of genetic materials between the two kinds of nuclei used. These results suggest that nuclei transfer technique is more efficient than conventional protoplast fusion technique for strain improvement of Trichoderma species.

• Journal of the Korean Geotechnical Society
• /
• v.20 no.6
• /
• pp.5-10
• /
• 2004

The earth pressure coefficient at rest for clayey soils in the one-dimensional state, $K_0$ obtained from the triaxial test is not correct in principle because the seepage flow is radial and the displacement of soil elements is three-dimensional. Measurements of the earth pressure and the pore water pressure during one-dimension consolidation in the consolidometer ring are presented. The earth pressure and pore water pressure are measured directly by a circular part of the consolidometer ring of a floating type at its mid height. A plastic clay showed $K_0$=0.5 irrespective of pressure in the consolidometer ring.

• Journal of the Korean Geosynthetics Society
• /
• v.22 no.1
• /
• pp.9-23
• /
• 2023

In this study, the design methods of self-supported retaining wall with cement treated soil constructed by vertical mixing method (trencher mixing method, V-DCM), which are using in domestic and foreign field, are investigated, and the characteristics of it are presented with comparing the results of numerical analysis with the drainage and construction conditions. The results indicated that the method 1 (total stress analysis) is the most aggressive, and method 2 (effective stress analysis) and method 3 are similar in the internal stress, and the stress and the horizontal displacement are effected on the soil type and drainage conditions in backfill of the wall. Also, in the case of the design combined with numerical analysis the method 1 can be applied, in that of the traditional design without the analysis the method 2 or the method 3 can be used. Finally, if the numerical analysis is only conduct, the tensile stress in excavation base and in boundary of the wall and the original ground have to be considered in the numerical analysis method.

• Journal of the Korean GEO-environmental Society
• /
• v.8 no.5
• /
• pp.39-46
• /
• 2007

In this study, the centrifuge tests were performed to investigate the lateral flow behavior and stability of the ground improved by SCP. The centrifuge tests were fulfilled in the case of the back of abutment filled by EPS (case 1) and soil (case 2), and the potentiometer was installed on the abutment and embankment to measure the vertical and horizontal displacement at the top of abutment. As a result, the vertical displacement measured at the back of abutment was maximum 2.1 m, which was about 12% if compared with the height of embankment. In the case of the back of abutment filled by soil, the vertical and horizontal displacement measured at the top of abutment was 10 cm and 1.1 m, respectively, which exceeded the allowable horizontal displacement. On the other hand, in the case of the back of abutment filled by EPS, the vertical displacement of abutment did nor occur and the horizontal displacement was 1.4 cm. Therefore, the effect of SCP improvement with EPS method adopted to prevent the lateral flow and assure the stability of embankment on the soft ground was far superior.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.36 no.3
• /
• pp.291-297
• /
• 2008

The launch of the COMS by using Ariane-5 launch vehicle is introduced. First, the COMS is introduced briefly, and then, the Ariane-5 launch vehicle is introduced including detail description of the improvement of Vulcain-1 engine of Ariane-5G to Vulcain-2 engine of Ariane-5ECA for 20% increase of thrust. Then, the launch process of the COMS is introduced. The COMS will be launched from the Guiana Space Center in Kourou, French Guiana. After the final check at PPF the COMS is transferred to HPF in the same building for fueling, and it is integrated to the launch vehicle adaptor at HPF, too. Then, this assembly is transferred to Final Assembly Building. After the satellites to be launched together are integrated to the launch vehicle on the launch table in the Final Assembly Building, the launch table loaded with the launch vehicle is moved to the launch pad for launch. The events during the launch vehicle flight is also introduced.

• Journal of the Korean GEO-environmental Society
• /
• v.13 no.2
• /
• pp.95-102
• /
• 2012

In this study, practical verifications for an advanced C.I.P(Cast in Place Pile) construction method were carried out. The structural characteristics of the method is to attach an angular joint in the steel-casing. This joint plays an important role in boring vertically, connected pile to pile, and protects the permeation of the ground water. For verifications, experimental research and numerical analysis were performed. In the experimental research, two model-tests were set up with the real scale steel-casing. One is to examine the leakage in the joint of piles and the other is to compare earth pressures in the front and the joint, respectively. In addition, 3 point bending test and compressive loading test were carried out and numerical analysis was performed to simulate the loading test. As a result of model-tests, the leakage in the pile joints was not shown up to 300 KPa of water pressure and stress concentration in the joint is out of the question. From the results of bending and compressive test, it was found that the new advanced C.I.P method is more convenient and superior than the conventional method.

• Journal of the Korean Chemical Society
• /
• v.42 no.5
• /
• pp.579-583
• /
• 1998

• Proceedings of the Optical Society of Korea Conference
• /
• 2003.02a
• /
• pp.124-125
• /
• 2003

바이오인포매틱스 기술이란 정보통신 인프라와 IT기술을 기반으로 분산되어 있는 대용량의 바이오 데이터 및 문헌 정보를 통합적으로 관리, 분석 및 처리하여 각종 바이오 정보 활용 분야(신약개발, 의료진단, 농산물 개량 등)에 효율적으로 응용 서비스하기 위한 IT-BT융합 핵심 기반 요소 기술을 의미한다. 2000. 6. 인간 유전체 초안 완성 후 대량 획득되는 바이오 데이터의 최대 부가가치 창출을 위해 대용량 바이오 데이터로부터 유용한 지식정보를 자동적으로 추출해내기 위한 효율적인 통합분석 기술이 필요하고 이는 바이오인포매틱스 기본 개념이 된다. (중략)