• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.847-852
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• 2003

The purpose of this paper is to develop the new deep mixing method installed automatic control equipments for the better construction in deep mixing and grouting. Civil, geotechnical, electronic, and communication experts have worked together for a long time for the development of automatic measuring devices using wire and wireless transmitting-receiving set. A series of laboratory and field experiments were carried out to check the reliability and field applicability of this system. New total automatic control system including automatic devices for checking angle, depth and quantity of injected grout was invented from the result of this research.

• 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.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.499-506
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• 2004

The use of dredged soft marine clay is increasing due to a shortage of coarse material available. This paper presents a stabilization method that can increase shear strength of the surface layer of a dredged clay deposit at dates much earlier than usual. The desiccation of the upper soft 1-2m layer can be accelerated by interrupting water seeping from its bottom with impervious geotextile. Just below the geotextile, enough pervious material is provided so that the underlying deposit can be drained through it. This scheme is proved to be effective through theoretical analysis.

• Journal of the Korean GEO-environmental Society
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• v.14 no.6
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• pp.31-38
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• 2013

This study carried out fundamental study on the forest road pavement method of cementing the ground using the compaction equipment after laying by mixing with eco-friendly stabilizer, natural soil and water. Target strength of pavement was set to 2.0MPa and the specimen was produced per mixing ratio of cement, kinds of natural soil and curing period to evaluate the durability and unconfined compressive strength. Unconfined compressive strength test was conducted to compare strength by producing the test specimen mixing environment-friendly cement as well as the test specimen mixing cement with the same mixing ratio. To evaluate the durability, surface abrasion test and water flow resistance test were conducted. In addition, SB and GB tests were conducted using iron marble and golf ball to evaluate the walking satisfaction since it can be used by visitors due to the feature of forest road.

• Journal of the Korean GEO-environmental Society
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• v.7 no.5
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• pp.49-55
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• 2006

Quick lime made from limestone that are deposited abundantly in Korea has excellent potentials for stabilization of clayey soils. If Korea is able to take advantage of its abundant supply, economical efficiency could be achieved through mass production as well as being able to take advantage of utilization of natural resources. For stabilizing of clayey soil with lime, it is necessary to determine the required quantities of lime firstly and to evaluate the degree of stabilization with lime content. In this test, the quantity of lime required for 2 clayey soils which located in Seunggok and Bugok province respectively, and for 2 clay minerals-kaolinite and montmorillonite-were determined by ASTM C 977-92 and were evaluated for solidification of each samples with changing lime contents by Atterberg limit test and pH test. It was also evaluated for the improvement of each sample with lime content and curing time. The sample which added lime content determined by ASTM C 977-92 increased plastic limit, unconfined compression strength, and decreased pH in increasing trend.

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.2
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• pp.74-77
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• 2005

The injection of cement stabilizer is used as one of ways to stabilize soft sea-bottom. However, this method makes an argument for the possibility of releasing heavy metals from the cement stabilizer to the seawater. To investigate the effect of the cement stabilizer on the seawater, field measurements were carried out in Ocheon harbor of the Chunsoo Bay. Although the highest concentrations of dissolved heavy metals were found in the surface seawater of the injection point and the metal concentrations decreased with distances, the levels of heavy metals in all the seawater met the demand of environmental criteria of Korea, US and UK.

• Geotechnical Engineering
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• v.13 no.1
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• pp.59-74
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• 1997

This paper presents the results of the geotechnical investigation and settlement analysis of a finished waste landfill to find the possibility of the site as a construction area. Also, the variations of the strength of the municipal waste after mixing with the several types of the particulate grouts are investigated. The materials of the grouts used in the experiment are Quick Lime, Portland Cement, Slag Cement and Geocrete Cement. The results of the geotechnical investigation show that the maximum dry unit weight of the waste becomes lower and optimum moisture content higher as the age of the disposed waste is younger and the organic content is higher. The thickness of the predicted differential settlements of the waste fill has large difference from location to location and the unconfined compression strength of the grout mixed waste from the experiment was higher in the order of Geocrete Cement, Slag Cement, Portland Cement and Quick Lime.

• Journal of the Korean Geotechnical Society
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• v.40 no.2
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• pp.55-64
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• 2024

While shield tunneling has demonstrated stability in international cases, the new Austrian tunneling method (NATM) encounters challenges in urban environments with shallow cover, weathered ground, and high groundwater levels. This paper introduces two typical collapse scenarios observed in urban areas, specifically within weathered bedrock and uncemented sandy soil layers. The collapses are analyzed using six stability evaluation methods, and the results are synthesized to assess the excavation face stability through a hexagonal diagram. The study finds a consistent agreement between the analysis results of the two collapsed tunnel sites and the evaluation outcomes. The employment of the stability evaluation diagram, a comprehensive method that considers the ground characteristics of the target tunnel, proves crucial for ensuring barrier stability during the tunnel design stage. This method is essential for a holistic evaluation, especially when addressing challenging ground conditions in urban settings.

• Journal of the Korean Geosynthetics Society
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• v.18 no.4
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• pp.115-127
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• 2019

The low-flow grouting injection technique, the target construction method for this study, is a method of pouring mortar into the ground by non-emission replacement principle, which can be expected to increase the density of the ground, and, in some cases, be used as a base file using the strength of the high injection solids, along with low noise, low pollution, and high durability. To verify that the dynamic characteristics of the ground are improved by the low-flow injection technique, the test work was conducted on the site and physical tests were performed, and the quality of the improvement formed in the ground was verified through the indoor test on the core and core recovery rate was analyzed. The density logs test layer calculated the volume density of the ground layer by using the Compton scattering of gamma-rays, and the sonic logs was tested on the ground around the drill hole using a detector consisting of sonar and receiver devices inside the drill hole. As a result of the measurement of the change in physical properties (density and sonic logs) before and after grouting, both properties were basically increased after infusion of grout agent. However, the variation in density increase was greater than the increase in speed after grouting, and the ground density measurement method was thought to be effective in measuring the fill effect of the filler. Strength and core recovery rates were measured from specimens taken after the age of 28 days, and the results of the test results of the diffusion and strength test of the improved products were verified to satisfy the design criteria, thereby satisfying the seismic performance reinforcement.

• Journal of the Korean GEO-environmental Society
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• v.17 no.10
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• pp.73-81
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• 2016

In the construction on low strength and high compressible soft ground, the many problems have been occurred in recent construction project. therefore, the soil improvement have been developed to obtain high strength in relatively short period of curing time. Based on the laboratory tests using undisturbed marine clay, the effect of improvement on soft ground was estimated. Deep mixing method by cement have been virtually used for decades to improve the mechanical properties of soft ground. However, previous researches set the focus on the short term strength the about 10% of cement treated clay. In this paper, cement and Natural Soil Stabilizer (NSS) were used as the stabilizing agent to obtain trafficability and mechanical strength of the soft clay. Based on the several laboratory tests, optimum condition was proposed to ensure the mechanical strength and compressibility as the foundation soil using cement and NSS mixed soil. Finally, research data was proposed about the applicability of NSS as the stabilizing agent to soft clay to increase the mechanical strength of soil.