• Journal of the Korean Geotechnical Society
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• v.17 no.4
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• pp.221-229
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• 2001

연약지반의 측방유동으로 인한 피해가 예상되는 국내 현장에 성토지지말뚝공법을 적용하기 위한 연구의 일환으로 실제 현장에서 성토지지말뚝이 발휘하는 효과를 규명하기 위한 현장시험이 계획되었다. 본 현장시험은 직경 40.64cm의 강관말뚝을 3본씩 총 4여로 시공하고, 각 열의 줄말뚝은 콘크리트캡보로 연결한 다음 총 8m까지 성토하였다. 현장시험은 총 2회에 걸쳐 수행하였으며, 성토지지말뚝의 하중분담효과를 확인하기 위해 하중계, 토압계, 지중경사계, 그리고 침하판을 이용한 계측을 실시하였다. 또한 계측결과를 제안이론식과 비교분석하였다. 이러한 연구 결과 성토지지말뚝을 시공할 경우 성토지지말뚝 위 성토지반속에 발달하는 지반아치에 의해 대부분의 성토하중이 말뚝으로 전이됨을 확인하였고, 말뚝캡보의 설치 간격이 좁을수록, 그리고 성토고가 높을수록 성토지지말뚝의 하중분담효과가 더 커지게 됨을 확인할 수 있었다. 또한 설계시 성토지지말뚝의 설치범위를 합리적으로 결정하기 위해서는 성토지지말뚝이 성토사면의 사면안정효과에 미치는 영향을 고려해야 함을 알 수 있었으며, 제안이론식이 현장상태의 성토지지말뚝에 합리적으로 적용될 수 있음을 입증하였다.

• Journal of the Korean Society of Safety
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• v.11 no.4
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• pp.151-155
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• 1996

The main purpose of this study was to develop a useful method for analysing slope stability by seepage force. The stability of an embankment impounding a water reservoir is highly depend upon the location of seepage line with the embankment, it is important to illustrate the seepage phenomenon. Of particular interest is the stability following a rapid rise change of reservoir level. Seepage forces in embankments are easily determined if frictional forces are expressed in relation to hydraulic gradient i. Seepage forces can combine with soil weights to improve stability or worsen it, depending on the direction in which the forces act ;n relation to the geometric cross section.

• Journal of the Korean GEO-environmental Society
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• v.20 no.1
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• pp.13-17
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• 2019

This paper presents case history of railway embankment excess settlement on soft clay during service in southern region of Korea. A lot of field observations show that the measured settlements are a lot larger than settlements actually calculated in this area. Back analysis is carried out to verify the soil parameters which are intended to investigate in the subsurface exploration phase and later in a laboratory test program. Recommendations and causes for the engineering practice are suggested to review the determination of excess settlements and, consequently, to improve the settlement prediction. This enormous discrepancy is due to the passing over secondary consolidation, and the design filling did not meet to real construction filling. Immediate settlement could be subsidiary factor of excess settlement.

• Advances in environmental research
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• v.4 no.3
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• pp.183-196
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• 2015

Migration of leachate generated through embankment of construction waste soil (CWS) in low-lying areas was studied through physical and chemical analysis. A leachate solution containing soluble cations from CWS was found to have a pH above 9.0. To determine the distribution coefficients in the alkali solution, column and migration tests were conducted in the laboratory. The physical and chemical properties of CWS satisfied environmental soil criteria; however, the pH was high. The effective diffusion coefficients for CWS ions fell within the range of $0.725-3.3{\times}10^{-6}cm^2/s$. Properties of pore water and the amount of undissolved gas in pore water influenced advection-diffusion behavior. Contaminants migrating from CWS exhibited time-dependent concentration profiles and an advective component of transport. Thus, the transport equations for CWS contaminant concentrations satisfied the differential equations in accordance with Fick's 2nd law. Therefore, the migration of the contaminant plume when the landfilling CWS reaches water table can be predicted based on pH using the effective diffusion coefficient determined in a laboratory test.

• Magazine of the Korean Society of Agricultural Engineers
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• v.14 no.2
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• pp.2661-2667
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• 1972

In the construction of earth dam, embankment, highway by filling, a compaction is to increase the density of applying pressure. By compaction interspaces between the soil graivos decrease so that density and adhesion increase but void and permeability decrease. Good compaction results in higher stablilty. The effect of the compaetion depends on a number of factors, of which the most important are soil charactesistics. Water content, and external force. In this study discussed is about sandy loam that since, with indentical force exerted and indentical compaction method, the effect of the compaction will be different due to the soil characteristics, the change of optimum moisture content and of maximum dry density by compaction yields difference in Compaction for a same sample.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.09a
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• pp.73-78
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• 2000

The reinforced soil has been widely used for constructing retaining walls and embankment with steep slope. However, the benefits of soil reinforcing are often-restricted by a lack of good quality backfill material. In this study, plane strain compression tests were carried out to study the effects of preloading on the behavior of geosynthetic-reinforced saturated clay. For the unreinforced and reinforced soil, drained and undrained shearing tests were peformed after anisotropic consolidation in a constant strain rate. A preoading test was carried out by preloading, creep, unloading, aging and undrained shearing after anisotropic consolidation(K=0.3, σ'₃=50 kPa). It was observed that a reinforced clay, Kanto loam, can have a great initial secant modulus in undraind condition by well compaction and over consolidation. The results shown that the increasing of drained strength should be used to apply a large preloading in the case of reinforced clay.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.177-184
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• 2000

Geotube is a tube made of geotextile and hydraulically filled with dredged soil. This technological method has been widely used in the advanced countries of the world to build the shore protection embankment. The dredged contaminated sediments from the lake, river, and harbor can be pumped into the geotube by using the hydraulic pump. So, environments effects can be minimized and enhanced by using this method. This paper presents a field test result of a geotube in the land reclamation project for the Songdo New City construction site. The dredged silty clay was dredged by the dredging ship and hydraulically pumped into the geotube. The height of geotube was measured at every filling stage and also measured width and diameter of geotube with the elapsed time. The unit weight of soil and undrained shear strength of filled soil in a tube were measured at the various locations and heights of geotube with the elapsed time. Geotube technique can be effectively implemented for the silty clayey soil with using the dredging ship.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.235-242
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• 2004

For this study, a Peliyagoda area located on a route was selected among many sections of a CKE(Colombo to Katunayake Expressway) route in Sri-Lanka. Its subground consists of a very weak and thick peat soil named amorphous or fibrous peat. All of data, obtained in the design process of soft ground treatment were analyzed to evaluate the settlement characteristics resulted from an embankment load and to present reasonable methods for estimation of secondary compression settlement. For these purposes, soil parameters were used obtainedby field and laboratory tests the settlement analyses were conducted base on the field monitoring results within 20 months. In addition, Reasonable methods were studied to estimate primary consolidation and secondary compression settlement.

• Magazine of the Korean Society of Agricultural Engineers
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• v.41 no.5
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• pp.93-98
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• 1999

The results of an experimental investigation on the characteristics of compaction and compressive strength of polypropylene fiber reinforced soil are presented in this paper. This study has been performed to obtain the physical properties of PFRS(polypropylene fiber reinforced soil) such as strain-stress relationships, OMC(optimum moisture contents) and ${\gamma}$dmax (maximum dry unit weight), with four different contents (i.e., 0.1%, 0.3%, 0.5% and 1.0% weights ) of mono-filament and fibrillated polypropylene fibers. From the compaction test results, it is found that OMC increased with the contents ratio of fiber, but ${\gamma}$dmax decreased. It means that the improvement of the workability and the reduction of the weight of embankment structures by the asddtion of the polypropylene fiber. And, from the compression test results, it is found that the additon of the polypropylene fiber remarkably improved the compressive strength of PFRS. And it was observed in the viewpoint of strength that the fibrillated polypropylene fiber reinforced soil is more effective than the mono-filament polypropylene fiber reinforced soil.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1090-1094
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• 2009

Many problems in geotechnical engineering such as slop failure, debris flow, ground heaving due to embankment, and lateral flow caused by liquefaction are related to large deformation rather than small deformation. Traditional numerical methods such as finite element and finite difference methods have a difficulty to solve such large deformations because they use grids. A particle method was developed for fluid dynamics. The particle method can solve large deformation problems because it uses particles to discretize differential equations. It can also include soil constitutive model and thus solve soil behavior on various boundary conditions. In this study, a particle method, which is based on particles rather than grids, is introduced and used to simulate large deformation including soil failure. The developed method can be applied for various large deformation problems in geotechnical engineering because it incorporates soil constitutive models.