• Title/Summary/Keyword: 성토다짐

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A Study on the Mechanical Characteristic and Shear Strength haracteristic on Elapsed Time of the Western Sea Dredged Soils (서해안 준설토의 역학적 특성 및 시간경과에 따른 강도 특성에 관한 연구)

  • Kim, Hongtaek;Han, Yeonjin;Yu, Wandong
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.2
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    • pp.31-41
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    • 2013
  • The dredged soils of western sea of Korea have been used as the fill materials because it possess the characteristics that constitute silt, silty sand and sand mainly. However, a study on dredged soils as the fill materials is insufficient. Hence, in this present study, the application the dredged soils of western sea of Korea as the fill materials was confirmed. Primary, the composition characteristics of the ground was analyzed to confirm the application on dredged soils as the fill materials by the piezo-cone penetration test. In laboratory test, it was performed the self-weight consolidation test for mechanical characteristics of the dredged soils. The direct shear test using self-weight consolidation test sample for shear strength characteristics was performed after self-weight consolidation test. Additionally, the mechanical characteristics of the dredged soils on elapsed time using self-weight consolidation test sample, which is drained naturally, was evaluated. The dredged soils of western sea of Korea show that unit weight and shear strength is increased as natural drain time elapses.

Characteristics of Dynamic Compaction Energy for a Non-plastic Dredged Soil (비소성 준설토의 동다짐 에너지 특성 연구)

  • Hwang, Seong Chun;Yoon, Sang Chun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.6
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    • pp.110-117
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    • 2011
  • Seashore landfill projects use undersea pump dredging method for construction of airport and factory site. Coarse grain soil from the dredging is considered for use at inland. West sea shore bottom consists of primarily coarser grained silt-sand and this component contains far more percentage than is the case with East sea and South sea area. This soil shows very different characteristic at consolidation and compaction behavior. This research targets to utilize this type of dredging soil. Test specimen is from West sea (Saemangum) dredged soil landfill site. Model analysis is done for getting prediction of original soil relative density and N-value from dynamic compaction energy variance. Dynamic compaction energy is calculated for efficient foundation design.

Seismic Behaviour of Eco-BELT System and Seismic Effectiveness of T-shaped Deadman Considering Soil-Structure Interface Based on Dynamic Numerical Analysis (흙-구조물 접촉면을 고려한 친환경 옹벽 구조물의 지진시 거동 및 T형 후방지지물의 보강효과에 대한 동해석 분석연구)

  • Kwak, Chang-Won;Park, Inn-Joon
    • Journal of the Korean Geotechnical Society
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    • v.37 no.8
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    • pp.37-49
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    • 2021
  • A retaining wall system is widely constructed civil structure to maximize the effectiveness of practical use of the land. Recently, the technology which is more eco-friendly and owns seismic stability of the retaining wall system becomes important. In this study, an Eco-BELT system using natural rocks as the front wall is introduced and the seismic characteristics of the Eco-BELT system are analyzed based on 2 and 3 dimensional numerical analysis. The soil-structure interface comprises between backfill soil and natural rocks are considered. The relative density is mainly considered to influence the seismic behavior of Eco-BELT system, and T-shaped deadman is also considered to judge the increase of seismic stability. As a result, lateral displacement of the wall decreases 29.5% in maximum under 90% of relative density and decreases 21.2 to 21.9% with T-shaped deadman, therefore, the seismic effectiveness of T-shaped deadman and increasing relative density of backfill are verified by numerical analysis.

A Study on Various Soil Stiffness Evaluation Methods with Field Test (현장시험을 통한 다양한 지반강성 평가방법에 대한 연구)

  • Yoo, Wan-Kyu;Kim, Byoung-Il;Kim, Ju-Hyong;Park, Keun-Bo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.4
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    • pp.1373-1380
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    • 2010
  • The plate loading test(PLT) and the field density test are mainly used on the construction of embankments to control the compaction of a limited layer thickness. These two test methods are very time consuming and inefficient, but they are still commonly used as the methods of quality control for soil compaction. In the last 3 decades, many devices such as geogauge, light falling weight deflectometer(LFWD) and dynamic cone penetrometer(DCP) etc., have been introduced into the engineering market with the objective of acquiring in situ stiffness properties of the compacted soil layers. Recently, a new type of sensor, called compactometer, which in mounted on the drum of a roller and measures impact forces continuously with GPS, called as Continuous Compaction Control(CCC), has come into use in many countries such as America, Germany, Japan and so on. The main objective of this paper is to assess the potential use of these new devices as quality control and assurance devices for compacted soil layers. Based on this study, compactometer and the LFWD results werestrongly correlated with the result obtained from the PLT and the field density test.

Temperature Effect on the Compaction Characteristic of Cohesionless Soil (온도에 따른 사질토의 다짐 특성)

  • Lee, Kicheol;Ji, Subin;Kim, Hobi;Kim, Dongwook
    • 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.

The Influence of Field Compaction Method on the Efficiency of Compaction and the C. B. R. Value (전압방법(轉壓方法)이 전압효과((轉壓效果) 및 C. B. R. 값에 미치는 영향(影響))

  • Chung, Sang;Kang, Yea Mook
    • Korean Journal of Agricultural Science
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    • v.10 no.2
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    • pp.292-309
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    • 1983
  • This study is intended to find out the degree of compaction in field compaction, with soil type, the thickness of soil layer and the number of roller passing through the field density test and the field C. B. R. test by comparing vibration and non-vibration compactions. The results in this study are summarized as follows. 1. When the number of roller passing is few, it shows that the efficiency of the compaction by vibratory compaction is greater than that by non-vibratory compaction, the difference of the compaction ratio between vibratory and non-vibratory compaction is decreased according as the number of roller passing is more frequent. 2. Mechanizing on a large scale it is possible for a large equipment to be able to reach the point of A-1 compact ion method with three to five times of roller passing. To provide for mechanizing on a larger scale it is advisable to fix the standard by the D-2 compaction method. 3. As dry-density increases, the C. B. R. value increases, but the increasing ratio of C. B. R. value showed greater in vibrating compacting. 4. According as the number of roller passing increases, the increasing tendency of the C. B. R. Value is slow and the difference of the C. B. R. value between vibration and non-vibration compaction is large, the C. B. R. value showed greater about 20% in vibration compaction than in non-vibration compaction. 5. In C-5 soil type, with increasing the thickness of compaction, the degree of compaction is decreased. When the thickness of compaction is increased from 20cm to 30cm, the degree of compaction is decreased slowly, while the thickness of the compaction is increased from 30cm to 40cm the degree of compaction is decreased remarkably. Therefore it is advisable to compact the ground under the thickness of 30cm.

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Engineering Characteristics of the Light Weight Soil Used Recycled Stylofoam Beads and Disposal Soils (폐스티로폴 입자와 현장 발생토를 활용한 경량혼합토의 공학적 특성)

  • Shin, Bang-Woong;Lee, Jong-Kyu
    • Journal of the Korean GEO-environmental Society
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    • v.1 no.1
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    • pp.43-50
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    • 2000
  • This paper presents the engineering property of light weight soil made of soil mixed with recycled stylofoam and stabilizer. Recycled stylofoam beads is able to use by lightweight fill materials because it is light, adiabatic, and effective for vibration interception. Especially, recycled stylofoam beads is easy to supply because stylofoam have been recycle item in 1996. In this study, physical and geotechnical properties of the light weight mixed soil(weathered granite soil mixed with Stylofoam Beads) were analyzed by laboratory experiments to examine its suitability for backfill materials. Laboratory tests were performed to evaluated strength, bearing capacity, weight, permeability, microphotograph analysis with variation of mixing ratio. Based on the results, it is concluded that the use of recycled stylofoam beads is acceptable lightweight fill.

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A Study on Self-Hardening Characteristics of Coal Ash by Mixing Ratio of Fly Ash and Bottom Ash (비회와 저회의 배합비에 따른 석탄회의 자경성에 관한 연구)

  • Shin, Woonggi;Lim, Daesung;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.11 no.6
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    • pp.85-91
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    • 2010
  • As enormous construction projects of land development are carried out around Korea, useful construction materials are needed to perform the construction projects. However, there are no more enough of fill and reclamation materials in our country. That is why the coal ash is expected to be utilized as an alternative material. Since the coal ash has the characteristics of a pozzolan and a selfhardening material, it is adjudged that coal ash has a great possibility to be used as a fill and reclamation material. In this study, grain size analysis, Atterberg limit test, and specific gravity test were performed to examine the physical characteristics of the coal ash about a self-hardening material before utilizing the coal ash in the construction. Compaction test, unconfined compression test, direct shear test, and flexible wall permeability test were conducted to investigate the engineering characteristics according to mixture ratios of fly ash and bottom ash. As a result of the tests, it was confirmed that the mixing ratio 1:1 of fly ash and bottom ash is the most effective to use as a fill and reclamation material. If the mixture of coal ash is used as a backfill material with light weight around structure, it is expected to play a significant role in reducing earth pressure on the back of the structure. As the age of the mixture of coal ash goes by, it intends to decrease the coefficient of permeability. As described above, the coal ash should be considered as an alternative material of fill and reclamation materials since the result of the tests indicates that the coal ash is suitable to a useful material on the construction design.

Field Compaction Characteristics of Domestic Bed Sediment as Levee Fill Material (제체재료로서 국내 하상토의 현장다짐특성)

  • Kim, Jin-Man;Kim, Kyung-Min;Choi, Bong-Hyuck;Lee, Dae-Yeong
    • Journal of the Korean Geotechnical Society
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    • v.24 no.10
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    • pp.113-120
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    • 2008
  • It is difficult to acquire good-quality fill material for levee in field and it is the most important factor of levee construction technology to use the bed sediment for the safe and economic construction. So, it is necessary to evaluate geotechnical characteristics of bed sediment, design and construction method through field application tests. In this study geotechnical characteristics of Hyunpoong bed sediment (SP) in Daegu were analyzed, and laboratory/field compaction test for mixing granite weathered soil (SW) was performed. And field mixing method was suggested.

A Soil Mechanical Study for a Practical Application to Forest Road Construction (임도설계(林道設計)에의 응용(應用)을 위한 흙의 토질(土質) 역학적(力學的) 특성(特性))

  • Kim, Ki Weon
    • Journal of Korean Society of Forest Science
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    • v.84 no.2
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    • pp.166-177
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    • 1995
  • This study was carried out to discuss how soils in the area planned for a forest road construction can be mechanically tested and practically applied. For this, 16 soil test samples from 8 plots(2 samples per plot) were used. The major tests are focused on unit weight before and after cut, water content, liquid and plastic limits, sieve and hydrometer analysis etc. The total unit weight(${\rho}_t$) before and after cut are $1.69g/cm^3$ and $1.19g/cm^3$, respectively. Their water contents are 21.0% and 20.5%. The coefficient of uniformity U and coefficient of curvature C obtained from sieve and hydrometer analysis are 125 and 0.42, which mean generally not well graded. On the soil classification by USCS, SM(silty sand or silt-sand mixed soil)is a Key soil, but it seems to be not good for fill material. From the standard proctor test are resulted $1.40{\pm}0.065g/cm^3$ for the unit weight(${\rho}$) in the nature and $1.88{\pm}0.049g/cm^3$ for the optimum proctor unit weight(${\rho}pr$) each. With this to say, it is necessary more powerful compaction work at earth filling, with which this soil reachs enough the ${\rho}pr$, and more earth.

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