• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.1
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• pp.43-48
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• 2010

Proctor test A or D method of compaction is the most common laboratory test for investigation of subgrade soil characteristics, however, compression type using roller is used in the field. The differences between laboratory and field compaction have considerable error as application to subgrade soil properties of laboratory test. The investigation of compacted soil is carried into effect to solve the problem. The gyratory compactor which is made to reproduce the field density of asphalt mixture, coming from traffic loads, has an advance to compact it similar to arrangement of field aggregate particles. This gyratory compactor has several problems of investigation of compacted soil, because it has designed to make initial asphalt specimens. The main objectives of this research are grasping problems when compacted soil test using the gyratory compactor and showing solutions. It has made a comparative study of difference of the percentage of water content and weight, which are before and after compaction, about the pressure of compaction, frequency of compaction and speed of compaction. And it also has investigated finding maximum percentage of water content which not occur change of percentage of water content after compaction and searching how has an effect on drawing compaction curve.

• Journal of the Korea Institute of Building Construction
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• v.15 no.1
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• pp.35-42
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• 2015

Although the interest for earth architecture has been expanded and settled as a part of modern architecture, precisely calculating the ratio of water content in practice is still difficult and the calculation is based on empirical analysis yet. This causes many problems in durability and maintenance of earthen architecture. Therefore, this study investigated to find the easiest way to correctly calculate the appropriate level of water content ratio (AWCR), which can be used in practice. Until now, the workers have checked the AWCR based on their own experience with popular but vague manuals. On this awareness, we studied the several testing methods and found the dropping test which uses the pattern of shape after the sample is dropped. In this point, we studied and developed the definite testing method in terms of process, and shape discrimination. Also we suggest the test recording sheet by using the cobalt chloride($CoCl_2$) whose color is instantly changed when contacts with the moisture. It is believed that this result can help improving the quality and durability of the earthen architecture using the rammed earth method and the efficiency in practice.

• 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 Society of Hazard Mitigation
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• v.9 no.1
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• pp.33-40
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• 2009

Compacted soil are used in almost roadway construction with compaction of soil. The direct consequence of soil compaction is densification, which in turn results in higher strength, lower compressibility, and lower permeability. The standard and modified Proctor tests are the most common methods. Both of these tests utilize impact compaction, although impact compaction shows no resemblance to any type of field compaction and is ineffective for granular soils. It has been dramatic advances in field compaction equipment. Therefore, the Proctor tests no longer represent the maximum achievable field density. The main objectives of this research are a survey of current field compaction equipment, laboratory investigation of compaction characteristics, and field study of compaction characteristics. The findings from the laboratory and compaction program were used to establish preliminary guidelines for suitable laboratory compaction procedures.

• Journal of the Korean GEO-environmental Society
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• v.18 no.1
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• pp.23-29
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• 2017

This study, to provide quantitative data related to compaction characteristics, identifies the compaction characteristics of various types of soil samplers, in relation to their particle-size distribution and plasticity degree, and the compaction characteristics of artificially created granular materials, in relation to their A & D compaction. The results of the experiments show as follows. $r_{dmax}$ of clay is less than those of both sand and gravel approximately by 10%. O.M.C of clay has turned out to be greater than sand and gravel approximately by 20% and 30%, respectively. Changes in the compaction characteristics can be observed clearly around 30~60% of sand and 30~50% of passing No.200 sieve. It has also been shown that the compaction characteristics related to LL and PL are similar to each other in changes, and that the compaction characteristics become less clear with higher percent of fine grained soil. The compaction characteristics of the artificially created granular materials and field materials have appeared almost similar to each other. $r_{dmax}$ is less approximately by 30% and O.M.C greater approximately by 20% in A compaction than in D compaction. As $r_{dmax}$ and O.M.C become greater, its rate increases.

• Journal of the Korean GEO-environmental Society
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• v.20 no.2
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• pp.41-48
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• 2019

Soil compaction is one of the most important activities in the area of civil works, including road construction, airport construction, port construction and backfilling construction of structures. Soil compaction, particularly in road construction, can be categorized into subgrade compaction and roadbed compaction, and is significant work that when done poorly can serve as a factor causing poor construction due to a lack of compaction. Currently, there are many different types of compaction tests, and the plate bearing test and the unit weight of soil test based on the sand cone method are commonly used to measure the degree of compaction, but many other methods are under development as it is difficult to secure economic efficiency. For the purpose of this research, a portable penetration meter called the Free-Fall Penetration Test (FFPT) was developed and manufactured. In this study, a homogeneous sample was obtained from the construction site and soil was classified through a sieve analysis test in order to perform grain size analysis and a specific gravity test for an indoor test. The principle of FFPT is that the penetration needle installed at the tip of an object put into free fall using gravity is used to measure the depth of penetration into the road surface after subgrade or roadbed compaction has been completed; the degree of compaction is obtained through the unit weight of soil test according to the sand cone method and the relationship between the degree of compaction and the depth of the penetration needle is verified. The maximum allowable grain size of soil is 2.36 mm. For $A_1$ compaction, a trend line was developed using the result of the test performed from a drop height of 10 cm, and coefficient of determination of the trend line was $R^2=0.8677$, while for $D_2$ compaction, coefficient of determination of the trend line was $R^2=0.9815$ when testing at a drop height of 20 cm. Free fall test was carried out with the drop height adjusted from 10 cm to 50 cm at increments of 10 cm. This study intends to compare and analyze the correlation between the degree of compaction obtained from the unit weight of soil test based on the sand cone method and the depth of penetration of the penetration needle obtained from the FFPT meter. As such, it is expected that a portable penetration tester will make it easy to test the degree of compaction at many construction sites, and will lead to a reduction in time, equipment, and manpower which are the disadvantages of the current degree of compaction test, ultimately contributing to accurate and simple measurements of the degree of compaction as well as greater economic feasibility.

• Korean Journal of Agricultural Science
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• v.10 no.1
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• pp.97-109
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• 1983

In this study, the effects on the soil compaction were investigated through the various testing method by changing the number of layers, the number of blows per layer and drop height. The results obtained in this study were summarized as follows. 1. Soil compaction was largely influenced by maximum grain size of soil in case of small testing mold diameter. 2. The compaction effect showed best in the well graded soil. In this test, compaction effect showed the best value in the soil which contained about 30~40% of particles finer than No. 200 sieves although it would vary according to the content of coarse grained soil. 3. Though the compaction method was changed at the level of compaction energy fixed, the effect of soil compaction showed little. 4. The increment of compaction energy increased the effect of soil compaction, but over a certain limit the soil compaction showed little on the effect. 5. In the method to increase the compaction energy for the purpose of the most reasonable effect, the soil compaction effect was differently shown according to the grain size distribution of the soil.

• Geotechnical Engineering
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• v.28 no.1
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• pp.39-44
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• 2011

TDR 함수량계는 전자기파를 이용하여 흙의 밀도와 함수비를 비파괴적으로 신속하게 평가하는 유망한 기술이다. TDR 시험법은 10~20cm 길이의 2~3개의 탐침을 지중에 관입시킨 후 전자기파의 이동시간을 측정하여 유전상수($K_a$)를 산정한다. 제안식을 이용하여 유전상수로부터 체적함수비(${\theta}$)의 산정이 가능하므로, 이 시험법은 흙의 함수비를 측정할 수 있는 비파괴시험 장치로 개발되어 활용되고 있다. 또한, 흙의 종류에 따른 보정상수가 파악되어 있는 경우에는 현장 밀도와 현장 함수비를 동시에 평가할 수 있으므로, TDR 함수량계를 이용하여 성토지만비나 노상토에 대한 신속하고 간편한 다짐관리가 기능하다.

• Journal of the Korean Geotechnical Society
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• v.32 no.2
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• pp.53-62
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• 2016

Among several factors controlling soil compaction, temperature is the factor that varies with region and season. Although earthwork is performed in many projects in the cold regions of the earth, studies on quantifying soil compaction associated with temperature are limited. This experimental study investigates the temperature effect on the soil compaction of cohesionless soil. Jumunjin sand was selected for the tests to represent cohesionless clean sand, which is widely used as an engineering fill at petrochemical projects such as northern Alberta of Canada and Russia. The laboratory test program consists of performing a series of standard proctor tests varying temperature of soil samples ranging from $-10^{\circ}C$ to $17^{\circ}C$. Test results indicate that soil specimen volume expansion occurred from bulking and its range was 0% to 6% with zero above temperature. For increasing temperature from $0^{\circ}C$ to $17^{\circ}C$, water content corresponding to maximum volume (minimum dry unit weight) was decreased and water content corresponding to minimum volume (maximum dry unit weight observed after reaching minimum dry unit weight) was slightly increased with increasing temperature. In zero below temperature, dry unit weight gradually decreased with increasing water content. In this case, no bulking effect was found and soil specimen volume increased due to the higher unit volume of ice.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.3 no.2
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• pp.109-117
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• 1983

Dynamic shear modulus of the compacted clayey soil was determined by the resonant column test to study the parametric effects of confining pressure, shear strain amplitude, molding water content, compaction energy, void ratio and the degree of saturation. The effect of each of these parameters on the dynamic shear modulus found to be significant and can be explained in terms of the changes in soil by compaction. Dynamic shear modulus of the compacted soil is increased significantly by compaction and compaction at the dry side of the optimum moisture content is much more effective. It is also found that the dynamic shear modulus showes a good correlation to the static shear strength of the compacted soil. Therefore the dynamic shear modulus of the compacted soil for a certain confining pressure may be obtained ea8i1y from the unconfined compression strength.