• The Journal of Engineering Geology
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• v.26 no.4
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• pp.439-445
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• 2016

The new airports apply the systematic runway foundation construction to build the high quality runways in order to take the leading position to win future aerial demands and stay ahead of competitors. This study is intended to supplement the weakness of existing standard compaction test to minimize residual settlement of lower weak foundation during operation of passenger berthage. The fill material was sampled from 4 construction sites using the fill material with diameter of 100mm or less, and the standard compacting test (KS F 2312), large circular mold compacting test, and water-replacement field density test (ASTM D 5030) were conducted. The regression analysis of correlation of the field density test and the standard indoor compaction test showed the unreliable value at P-value of 0.05, and the regression analysis of the field density test and the large indoor compaction test showed the high correlation with R value of 0.8878. It is judged that the construction of overall uniform quality can be assured as the site condition is truly reflected only if the compacting test method is selected in consideration of maximum size of fill material when evaluating the maximum dry density used in design and construction.

• International Journal of Highway Engineering
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• v.9 no.4
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• pp.55-63
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• 2007

Deformational characteristics of subgrade soils are important properties in the mechanistic analysis and design of pavement system. In this study, to evaluate the effect of specimen construction methods on deformational characteristics of subgrade soils in Korea, resonant column tests were performed for specimens constructed by various methods. Specimen construction method affected to the modulus value but the variation in the normalized modulus reduction curve was almost identical. The effects of specimen construction method on modulus are decreased with increasing confining pressure. The average maximum variation in the modulus value with different specimen construction methods was estimated as 16.8%. The differences in the modulus value of the specimens with same water content and dry density conditions that made by gyratory compaction and impact compaction were very small within 5.2%. The impact compaction method was proposed as a specimen construction method for determining the design input parameter testing considering that impact compaction method is much simpler and require less expensive specimen construction equipment and setup than gyratory compaction method.

• 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.

• The Science & Technology
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• s.476
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• pp.46-49
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• 2008

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.884-891
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• 2003

이 논문는 지오신텍스 보강토 구조물의 보강 메카니즘을 수치계산을 통해 규명하고자 하는 목적으로 쓰여졌다. 이 연구에서는 보강 메카니즘은 전단에 의한 다짐토의 체적 팽창(부의 다일렌탄시)을 지오신텍티스에 의해 구속 억제하는 과정에서 생성되는 효과로 간주하고 있다. 보강 메카니즘의 규명을 위해 1992년 일본 Kanazawa에서 실시된 실모형 실험과 실내 실험 결과를 이용하였으며. 수치계산에서는 다짐토의 다일렌탄시 특성을 표현 가능한 탄소성 구성모델을 이용하여 유한요소(FEM)을 이용하고 있다. 수치 계산에 의해 실모형, 실험 실내실험 결과를 비교 분석하였다.

• Journal of the Korean GEO-environmental Society
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• v.3 no.3
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• pp.65-77
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• 2002

Based from the results of various field and laboratory tests, it was determined that VCCP(Vibrated Crushed-stone Compaction Pile) Method is more effective compared to SCP(Sand Compaction Pile) Method. VCCP method effectively increases soil bearing capacity and reinforces soil and slopes, prevents liquefaction, enhances drainage. But when it comes to the engineering design these factors are not considered, instead designs are performed using practical methods and equations. Furthermore, this method is very economical since crushed stone can be used instead of sand and it can be also used in off-shore construction. In this paper, it will be synthetically considered technical state at the present time, research object after this and necessity of research for VCCP Method.

• Journal of the Korean Geotechnical Society
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• v.16 no.5
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• pp.157-168
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• 2000

토류구조물의 안정문제로는 장단기적으로 정적인 경우와 동적인 경우, 그리고 지반의 동적 거동특성, 흙의 강도저하 등을 미리 파악하여 기술적인 대처를 할 필요가 있을 것이다. 본 연구에서는 실내 모형 실험을 통하여 구조물의 배면에 토성이 다른 일반모래, 표준모래, 점성토를 뒷채움하여 다짐없이 강사만 하고, 룰러다짐, 진동다짐을 하여 토피의 수평 진동거리를 길게, 짧게 그리고 중간으로 하여 강성벽체에 작요？는 수평토압에 대한 정적, 동적 특성을 규명하는 것이다. 모형 실험장치로는 실험대, 토조, 토압측정장치, 진동하중 발생장치, 진동측정장치, 강사기, 롤러 등을 설치하여 거리에 따른 병진운동으로 가속도와 수평토압, 수평토압계수, 전체토압, 토압의 작용점, 지진토압증분 증을 구하여, 실험결과와 기존 이론결과, 그리고 유한요소 해석결과와 비교 고찰하였다.

• Journal of the Society of Disaster Information
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• v.19 no.4
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• pp.950-957
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• 2023

Purpose: The response technology is needed to prevent the spill of highly toxic oil contaminants in advance. Therefore, this paper described the results of an experimental study to predict the engineering properties of the developed reactive material. Method: Compaction tests and spectral information acquisition experiments were conducted on the reactive materials, and the results were evaluated. In addition, the correlation between spectral information and maximum dry unit weight was analyzed to evaluate the possibility of predicting the engineering properties for reactive materials. Result: The compaction test results showed that the maximum dry unit weight was in the range of approximately 9kN/m³ to 10kN/m³. The spectral information confirmed that the maximum reflectance decreased as the polynorbornene decreased. Conclusion: It was confirmed that the maximum dry unit weight of the reactive material for absorbing oil contaminants can be predicted using the maximum reflectance according to the component ratio of the reactive material.

• 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.

• Journal of the Korean GEO-environmental Society
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• v.21 no.9
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• pp.25-32
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• 2020

The underground utilities installed under the ground is an important civil engineering structure, such as water supply and sewerage pipes, underground power lines, various communication lines, and city gas pipes. Such underground utilities can be exposed to risk due to external factors such as concentrated rainfall and vehicle load, and it is important to select and construct an appropriate backfill material. Currently, a method mainly used is to fill the soil around the underground utilities and compact it. But it is difficult to compact the lower part of the buried pipe and the compaction efficiency decreases, reducing the stability of the underground utilities and causing various damages. In addition, there are disadvantages such as a decrease in ground strength due to disturbance of the ground, a complicated construction process, and construction costs increase because the construction period becomes longer, and civil complaints due to traffic restrictions. One way to solve this problem is to use a liquid filler. The liquid filler has advantages such as self-leveling ability, self-compaction, fluidity, artificial strength control, and low strength that can be re-excavated for maintenance. In this study, uniaxial compression strength test and fluidity test were performed to characterize the mixed soil using marine clay, stabilizer, and in-situ soil as backfill material. A freezing-thawing test was performed to understand the strength characteristics of the liquid filler by freezing, and in order to examine the effect of the filling materials on the corrosion of the underground pipe, an electrical resistivity test and a pH test were performed.