• Journal of the Korean Geotechnical Society
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• v.27 no.8
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• pp.5-16
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• 2011

The objective of this paper is to assess the potential use of the resilient force of the ground obtained from an accelerometer and to propose a new compaction control process. Several comprehensive field experimental programs were conducted to analyze the correlation of compaction results obtained from an accelerometer and conventional test methods (e.g. the plate load test and field density test). This study focused on comparing the compaction results obtained from an accelerometer with conventional test results statistically. Based on the statistical analysis results, impact and resilient force measured from an accelerometer, mounted on the drum of a roller are very useful factors for continuous compaction control. A new compaction criteria determination process using an accelerometer is also proposed in this study.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.1C
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• pp.19-27
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• 2011

This paper evaluates the applicability of wave-based nondestructive methodologies and a penetration test for compaction quality measurements during road construction. To evaluate the physical and mechanical properties of compacted subgrade soil layers, soil stiffness gauge (SSG), time domain reflectometry (TDR), and miniature electro-mechanical systems (MEMS) accelerometers were used to nondestructively evaluate the soil response during and after compaction and dynamic cone penetrometer (DCP) profiles were used to evaluate the soil shear strength after compaction was completed. At the field site, two types of soils were compacted with four different compaction equipments and energies. Field testing results indicate that soil parameters evaluated by different testing methods, which are SSG, TDR, MEMS accelerometer, and DCP, are highly correlated. In addition, it is shown that the physical and mechanical tests deployed in this study can be used as alternative methods to the conventional compaction quality evaluation methods when assessing the overall quality and the engineering response of compacted lifts.

• Journal of the Korean GEO-environmental Society
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• v.16 no.8
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• pp.13-20
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• 2015

Due to the population growth and exhaustion of resource, the development on the harsh environment such as cold weather is emerging as an alternative for new resource development. The permafrost area covers about 14 percent of the world's land area and the global construction market for such area is rapidly expanded. Whereas the developed countries have already recognition of the need for research of coldest place and invested heavily in technology development, the domestic technology for the coldest place development is less developed and related research has rarely been performed. There is not a detailed national specification standard for the strength and deformation properties of the earthworks at sub-zero temperature but simple field directions. Therefore, the D compaction tests were conducted on the sand with fine contents of 0%, 5%, 10% and 15% at room temperature ($18^{\circ}C$), $-3^{\circ}C$ and $-8^{\circ}C$ to investigate the effect of the compaction energy on the compacted soils at sub-zero temperatures. Based on the test results, the larger compaction energy, the larger maximum dry unit weight under sub-zero temperature and D type compaction at $-3^{\circ}C$ show similar max. dry unit weights as those obtained from the compaction at the room temperature. However, compaction at $-8^{\circ}C$ showed significant performance degradation regardless of the compaction energy.

• Journal of the Korean GEO-environmental Society
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• v.5 no.4
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• pp.33-45
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• 2004

In the present study, more systematic laboratory model tests under various conditions are carried out to investigate load-sharing characteristics among the granular pile and adjacent soils and bearing capacity characteristics with different pile lengths. Further to evaluate effects of both a loading area and a spacing of pile installation on the bearing capacity and bearing capacity characteristics of each pile in group, model test results are also analyzed for the purpose of an efficient design of granular compaction piles. From the analysis of the model test results, it is found that the ultimate capacity of granular compaction group piles increases with a decrease in the installation distance among granular piles. It is also found that the dominant failure mode of the granular compaction piles is bulging failure. It is further realized that the length of a granular pile could not significantly affect on the ultimate granular pile capacity.

• Journal of the Korean Geosynthetics Society
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• v.17 no.1
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• pp.11-20
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• 2018

Surplus soil is commonly used at construction sites, because suitable fill material is not always immediately available and leads to additional costs. However, most surplus soils do not meet the requirement of suitable fill material to achieve the stability and strength of embankments. In this study, Proctor compaction tests and field compaction tests were performed by installing geosynthetics to resolve the problems caused by compacting unsuitable soils. Compaction energy and the number of geosynthetics were changed under the type A- and D- and type A Proctor compaction tests (KS F 2312), respectively. The field compaction testing using geosynthetics was performed on surplus soils of high water content. Optimum water content and maximum dry density of compacted soil decreased and increased by reinforcing geosynthetics, respectively. Compaction curves behaved with geosynthetics as the compaction curves behaved with higher compaction energy. Efficient compaction was possible because the compaction energy increased to 2.10 and 2.71 times the compaction energy required to achieve the same maximum dry density with one and two geosynthetic layer(s), respectively. Furthermore, field compaction tests verified that efficient compaction was possible because the dry density of unsuitable surplus soils of high water content was increased by reinforcing geosynthetics.

• Journal of the Korean Geotechnical Society
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• v.19 no.2
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• pp.57-64
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• 2003

The liquefaction potential of saturated sands under seismic loading conditions has been carefully considered by many investigations. Typical of these investigations is the laboratory determination of cyclic strength of sands by means of cyclic triaxial tests. This study was conducted to investigate the effects of the method of sample preparation on the liquefaction characteristics of remolded samples of saturated uniform sands. Cyclic triaxial tests were performed on saturated uniform sand compacted to the same density by 3 different procedures of pluvial compaction through air, pluvial compaction through water and vibratory compaction. It was validated that the cyclic stress ratio of remolded saturated uniform sands by different compaction procedures at the same density was very different.

• Journal of the Korean Geotechnical Society
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• v.23 no.12
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• pp.5-11
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• 2007

Among soft ground improvement methods by using granular material, the sand compaction pile method has been widely utilized in Korea, but, as a result of shortage and increase of unit price of sand, a necessity of an alternative method has been required. In this study, a series of in-situ static load tests for crushed-stone compaction piles were performed. Pile diameter was fixed to 700mm and areas of loading plates were changed. The static load tests were performed for area replacement ratios of 20, 30 and 40% respectively. Based on the test results, bearing capacity of single crushed-stone compaction pile was estimated. It showed that the settlement decreases as the replacement ratio increases. Also, a yielding capacity equation of the crushed-stone compaction pile considering replacement ratio was suggested.

• Journal of the Korean Geotechnical Society
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• v.16 no.5
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• pp.75-81
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• 2000

본 연구에서는 진동대 시험을 실시하여 지진동에 대한 일반 안벽 구조물과 내진 보강된 안벽 구조물의 동적거동을 분석하고 내진보강기법의 성능을 평가하였다. 진동대 시험은 기초지반이 조밀한 경우와 느슨한 경우, 자갈 뒤채움재를 설치한 경우 그리고 내진대책공법으로 경량재 치환공법과 모래다짐말뚝 공법을 적용한 경우 등 총 5가지 시험단면에 대하여 실시하였다. 과잉간극수압, 가속도 반응 그리고 지반의 변형양상을 분석한 결과, 기초지반과 뒤채움 지반의 연약화가 안벽 구조물의 동적거동에 큰 영향을 미치며, 경량재 치환공법과 모래다짐말뚝공법이 안벽 구조물의 내진성능을 향상시키는에 효과적인 것으로 나타났다.

• Journal of the Korean GEO-environmental Society
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• v.22 no.3
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• pp.5-13
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• 2021

Due to population growth and industrial development, the amount of industrial waste is increasing every year. In particular, in a thermal power plant using finely divided coal, a large amount of coal ash is generated after combustion of the coal. Among them, fly ash is recycled as a raw material for cement production and concrete admixture, but about 20% is not utilized and is landfilled. Due to the continuous reclamation of such a large amount of coal ash, it is required to find a correct treatment and recycling plan for the coal ash due to problems of saturation of the landfill site and environmental damage such as soil and water pollution. In recent years, the use of a fluid embankment material that can exhibit an appropriate strength without requiring a compaction operation is increasing. The fluid embankment material is a stable treated soil formed by mixing solidifying materials such as water and cement with soil, which is the main material, and has high fluidity before hardening, so compaction work is not required. In addition, after hardening, it is used for backfilling or filling in places where compaction is difficult because higher strength and earth pressure reduction effect can be obtained compared to general soil. In this study, the possibility of use of fluidized soil using high water content cohesive soil and coal ash is considered. And it is intended to examine the flow characteristics, strength, and bearing capacity characteristics of the material, and to investigate the effect of reducing the earth pressure when applied to an underground burial.

• Proceedings of the Korean Geotechical Society Conference
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• 1996.10a
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• pp.227-236
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• 1996