• 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.

• Geomechanics and Engineering
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• v.34 no.6
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• pp.665-681
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• 2023

Liquefaction is one of the most devastating geotechnical phenomena that severely damage vital structures and lifelines. Before constructing structures on problematic ground, it is necessary to improve the site and solve the geotechnical problem. Among ground improvement methods dealing with liquefaction, gravel drain (GD) columns and deep soil mixing (DSM) columns are popular. In this study, the results of a series of seismic experiments in a 1g environment on a structure located over liquefiable ground with different thicknesses reinforced with GD and DSM techniques were presented. The dynamic response of the reinforced ground system was investigated based on the parameters of subsidence rate, excess pore water pressure ratio, and maximum acceleration. The time history of the input acceleration was applied harmonically with an acceleration range of 0.2g and at frequencies of 1, 2, and 3 Hz. The results show that the thickness of the liquefiable layer and the frequency of the input motion have a significant impact on the effectiveness of the improvement method and all responses. Among the two techniques used, DSM in thick liquefied layers was much more efficient than GD in controlling the subsidence and rupture of the soil under the foundation. Maximum settlement values, settlement rate, and foundation rotation in the thicker liquefied layer at the 1-Hz input frequency were higher than at other frequencies. At low thicknesses, the dynamic behavior of the GD was closer to that of the DSM.

• Geomechanics and Engineering
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• v.19 no.6
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• pp.543-554
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• 2019

İzmir Bay reserves high amount of residual alluvial deposits generated by Meles River at its stream mouth. These carried sediments with high water content and low bearing capacity are unsuitable in terms of engineering purposes. In-situ soil stabilization with deep soil mixing method is considered to improve properties of soil in this location. This method is widely used especially over Scandinavia, Japan and North America. Basically, the method covers mixing appropriate binder into the soil to improve soil profile according to the engineering needs. For this purpose, soil samples were initially provided from the site, classification tests were performed and optimum ratios of lime and cement binders were determined. Following, specimens representing the in-situ soil conditions were prepared and cured to be able to determine their engineering properties. Unconfined compression tests and vane shear tests were applied to evaluate the stabilization performance of binders on samples with different curing periods. Scanning electron microscope was used to observe time-dependent bonding progress of binders in order to validate the results. Utilization of 4% lime and 4% cement mixture for the long-term performance and 8% lime and 8% cement mixture for short term performance were suggested for the stabilization of Meles Delta soils. Development of CSH and CAH in a gel form as well as CSH crystals were clearly observed on SEM images of treated specimens.

• Journal of the Korean Professional Engineers Association
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• v.44 no.6
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• pp.45-50
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• 2011

As the Deep Cement Mixing Method is composed of drilled natural soft soil structure and injected cement slurry to be mix together in it, the nature of excavated ground is influenced directly to the application of constructability. Also the nature of in situ soil is the main material, the mix design and construction work plan should be established before the investigation of soil which is performed through the whole site confirm the soil parameter before construction. The nature of investigated soil and water level as should be performed accurately.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.1142-1147
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• 2006

Cement-stabilized clay has widespread applications in Deep Mixing projects, whereby soft deep clay deposits are improved through the addition of cement. While much research on this subject has taken place over the past decade, the strength and deformation behaviour of cement-stabilized clay is still not well understood. An extensive laboratory program was conducted on kaolin stabilized with up to 10% cement. Water curing was employed for durations up to 112 days. To study the microstructure of raw and stabilized soil, use is made of SEM. Micrographs of selected raw and stabilized soil were obtained. These micrographs were closely analyzed for any change in the microstructure of the soil as a result of stabilization.

• Journal of Korea Soil Environment Society
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• v.4 no.2
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• pp.163-174
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• 1999

This paper presents a case history of remedial action adopted for contaminated groundwater in a landfill. The objectives of the projects are : (1) to effectively confine contaminated groundwater with an economically reasonable means, (2) to prevent further contamination of soil by collecting and treat the contaminant. and (3) to assure the environmental safety of the landfill during its operating period. Reported are the process from site investigation, through design and construction of an appropriate remedial action, to the monitoring of the selected confinement system. In view of the results of site investigation, deep soil mixing cutoff wall using the DMW(deep soil mixing cutoff wall) method and specially produced HEC soil stabilizer were used for the construction of deep soil mixing cutoff wall. For rock foundation with sever fractures, chemical grout curtain with urethane was installed. The monitoring results to date indicate that the selected vertical barrier performed satisfactorily.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.257-267
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• 2006

The earth retaining wall systems for excavation works in a populated urban area or a poor soil deposit can be limited due to various restriction. Thus there are various methods to be applied for them such as the soldier pile method, the diaphragm wall with counterfort and so on. In this study, the self-supported earth retaining wall using the DCM(Deep Cement Mixing) method, including its merits, demerits and some important characteristics occured in the design and the construction stage, was introduced. It might be reference for the other design and construction procedures using the DCM method.

• Journal of the Korean Geosynthetics Society
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• v.15 no.2
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• pp.1-12
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• 2016

In this study, laboratory mixture design test and field test were performed to evaluate applicability of eco-friendly binder material (CMD-SOIL) using desulfurized dust in deep cement mixing method (DCM). As a result of laboratory mixture design test, the uniaxial compressive strength of CMD-SOIL was up to 1.136 times bigger than slag cement by changing the water content, mixing rate, and W/B. Also, it had shown the strength up to 1.222 times bigger in shell content and up to 1.363 times in mixing of floating soil. As a result of field test, field strength/laboratory design criterion strength ratio (${\lambda}$) is shown 0.77. And this result was similar to earlier studies. From this result, CMD-SOIL can show the same efficiency compared with existing binder.

• Journal of the Korean Geosynthetics Society
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• v.20 no.4
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• pp.43-52
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• 2021

As port development in soft ground is actively promoted for international logistics and transportation, the Deep Mixing Method (DMM) is continuously applied to form an improved column body directly in the ground by mixing cement with soil to secure the stability of the structure. However, in the case of cement, there is a problem of emitting a lot of greenhouse gases during the production process, so the development and use of new alternative materials are socially required to achieve the national goal of carbon neutrality. Accordingly, in this study, CMD-SOIL, developed to induce a hardening reaction similar to cement by recycling recycled resources, was used as a ground improvement material for the DMM. In addition, it was attempted to determine the possibility of replacing cement by conducting on-site test construction and evaluating applicability. As a result of the study, the compressive strength of CMD-SOIL compared to the design reference strength was 1.46 to 2.64 times higher in the field mixing test and 1.2 to 5.03 times higher than in the confirmed boring. In addition, the ratio (λ) of the compressive strength in the field to the design reference strength was 0.63 to 1.14, which was similar to the previous research results. Therefore, in the case of CMD-SOIL, it is possible to express the compressive strength necessary to secure stability, and there is no difference in applicability compared to existing materials such as ordinary portland cement and blast furnace slag cement, so it was analyzed that it could be used as a ground improvement material for the DMM.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.7
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• pp.3216-3223
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• 2012

Deep cement mixing method (DCM) is one of the most effective improving methods for deep soft ground. The strength of soft soil can be increased in a short period of time with less noise and vibration. However, it is necessary to determine the stress transferring and concentration ratio of the composite soft ground for estimating the settlement behaviors. In this study, a model test was undertaken to investigate the stress distribution of the improved soil. Results of the model test shows that stresses were concentrated mainly on the improved areas by DCM and the concentration ratios (35.4, 28.6, 27.02) were obtained using several different techniques. These were well in accordance with other previous research results (26.52, 32.5).