• 한국지반환경공학회 논문집
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• 제3권3호
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• pp.65-77
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• 2002

여러 가지 현장 시험과 실내 시험 결과 진동쇄석말뚝공법은 기존의 모래말뚝공법에 비해 지지력증대, 지반보강, 사면보강, 액상화 방지억제 그리고 배수촉진 등의 효과를 극대화할 수 있는 공법으로 알려져 있으나, 설계실무에서는 경험적인 방법이나 공식에만 의존하여 설계가 이루어지고 있는 상태이다. 또한, 이 공법은 경제성을 갖춘 대체재료(즉, 쇄석)의 활용이 가능한 공법으로 해안 구조물의 시공에 적극적으로 활용가능한 공법이다. 본 연구에서는 쇄석말뚝에 대한 현 단계에서의 기술적 수준과 향후 연구방향 및 연구의 필요성에 대하여 고찰하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.1042-1050
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• 2008

In this study, SCP method was used by purpose to improve loose sand and soft clay that is drilled Sand Compaction Pile in underground. Settlement behavior of field analyzed through SCP method. When sand Compaction Pile drilled in clay, forming composite ground that foundation and Sand Compaction Pile behavior. According to SCP method can expect bearing capacity improvement, Settlement reduction, lateral flow protection. SCP increase the consolidation settlement of ground and it reduce settlement for that purpose increase liquefaction resistance, lateral Resistance. Because SCP had been widely used for sand. Area of Inchon-A by sand compose clay and silt to upper Ground and compose soft clay to under ground. After pre-loading, it measured settlement by extensometer and settlement extensometer that purpose of ground improvement with 13% in replacement ratio. The result analyzed settlement behavior is similar to Multi-layered Ground that it happened to elastic settlement at upper ground and to consolidation settlement at under ground.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.472-485
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• 2008

In this study, sand compaction pile method was adopted to improve the soft ground under the permanent dyke, namely west sea dyke of Incheon New Port. The row replacement ratio 30% was applied to consider the ground condition, environmental side and the construction cost of the site. The stability and displacement analysis was carried out by respectively SLOPE/W and PLAXIS 2D program. Based on this analysis, it is found that the safety factor and displacement is within an allowable criteria. The model experiment was carried out using the acryl soil box with $400(H){\times}1200(L){\times}250(W)mm$ to show the displacement of the dyke and behavior of soft ground. Based on this experiment results, it is found that the settlement does not occur from 1 and 2 loading phases and horizontal displacement of 0.0075% occurs from 2 phases. It is also found that the differential settlement occurs 0.05mm corresponding respectively 0.02% and 0.03% of the dyke height(15cm).

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.394-401
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• 2006

This study developed two dimensional finite element program(FE-SCP) for the analysis of a composite ground reinforced by sand compaction piles with a low area replacement ratio based on the Mohr-Coulomb elastic perfectly plastic constitutive model. Program FE-SCP give some conveniences to users such as automatic mesh generation according to the replacement ratio and the effective sand pile diameter in the post processor. Also, it contains optimum processor in calculation of In-situ stress equilibrium considering different coefficient of earth pressure between sand pile and surrounding clay. Estimated stress-strain behavior using FE-SCP and the measured one from a centrifuge test showed good agreement comparing to the result from a general finite element program.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.982-989
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• 2005

In this study, a series of laboratory tests based on 'Unit-cell concept' are performed to investigate improvement characteristics of clay ground in sand compaction pile method. Settlement reduction characteristics of composite ground and improvement characteristics of clay part could be qualified. In these procedure, the new strain-compression index($C_{\epsilon}$) of composite ground are adopted to show compressibility of composite ground according to the area replacement ratio, which is similar to the compression index($C_c$) in pure clay ground. Also, using normalization of reduction of water content in composite ground to the initial water content, improvement characteristics of clay part are investigated.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.362-371
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• 2006

The behaviour characteristics of Granular Compaction Pile(GCP) are mainly governed by the lateral confining pressure mobilized in the matrix soft soil to restrain the bulging failure of the granular compaction pile. The GCP method is most effective in soft soil with untrained shear strength ranging from $15\sim50\;kPa$. However, the efficiency of this method is falling down in the more compressible soil conditions, which does not provide sufficient lateral confinement. In the present study, the GCP method reinforced with uniformly graded permissible concrete is suggested for the extension of application to the soft ground. Also, large triaxial compression tests are conducted on composite- reinforced soil samples for verification of availability of the suggested method and the settlement estimation method of the reinforced GCP is proposed. Further, for the verification of a validity of the proposed method, predicted settlements are compared with results of numerical analyses. Tn addition, parametric studies are performed together with detailed analyses of relevant design parameters.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.1132-1140
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• 2009

Recently soil improvement methods are using in many ways such as costal and soft ground of inland. Among them, sand compaction pile be widely used because of quiet few advantages. There are two ways for quality evaluation method of sand compaction pile. Especially standard penetration test is used the most general method. However, Current method have problems in that it is not consider the condition of construction site. Therefore this study is propose new quality evaluation method. Relation of N-$\Phi$ is always not fixed but changing by condition of construction site. By through the Laboratory test we can know relationship between relative density and internal friction. Also this study propose revision for effective stress. From these study, we can acquire more accurate and reasonable result than current method.

• 한국지반환경공학회 논문집
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• 제5권2호
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• pp.51-62
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• 2004

조립토 다짐말뚝(granular compaction pile)공법은 비교적 강성이 크고 압축성이 작은 자갈, 쇄석 및 모래 등의 조립질 재료를 사용하여 연약한 지반에 말뚝을 조성하는 공법으로, 기초지반의 지지력 증가, 침하량 감소 및 압밀배수 촉진 등에 의한 지반개량 효과뿐 아니라, 사질토 지반에 적용시 지진에 의한 액상화 방지효과도 큰 공법으로 알려져 있으나 국내에서는 아직까지 널리 사용되지 않고 있다. 일반적으로 조립토 다짐말뚝은 Piled-raft system으로 시공되므로, 이 때 조립토 다짐말뚝의 극한지지력에 대한 평가는 팽창파괴 중심부의 깊이에 따라 달라지게 된다. 또한 조립토 다짐말뚝과 주변지반과의 하중분담에 대한 영향 및 지반내에서 조립토 다짐말뚝에 작용하는 구속응력의 변화를 적절하게 고려하여 조립토 다짐말뚝의 극한지지력이 결정되어야 한다. 본 연구에서는, 김 등(1998)에 의하여 연구되었던 조립토 다짐말뚝의 극한지지력 평가에 대한 해석기법을 토대로, 단일 말뚝에 대하여 상재하중의 크기, 재하면적의 크기 및 파괴깊이에 따른 수평구속응력의 변화를 고려하여 극한지지력을 산정하기 위한 기법을 제안하였다. 또한 제안된 조립토 다짐말뚝의 극한지지력 평가기법의 타당성을 실내모형실험을 통하여 검증하였으며, 실험결과를 토대로 하여 군말뚝의 지지력 증가효과 및 압밀계수의 변화에 대하여 비교, 분석을 실시하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 가을 학술발표회 논문집
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• pp.71-76
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• 2000

In generally, grouting consists of injecting a suspension or solution into the voids of soils. The low slump mortar grout has been used in America since 1950's. The Compaction Grouting, the injection of a very stiff under relatively high pressure, form a cylinderical grout support pile. The grout generally does not enter soil pores but remains in homogeneous mass that gives controlled displacement either to compact loose soils, or for lifting of structures, or both. In this paper, on the case of the reinforcement construction of 00 plant that the foundation's bearing capacity is insufficient and is to reinforce the foundation, a study has been peformed to analyze the effectiveness of the ground improvement. The bearing capacity of the Compaction Pile has been verified by the S.P.T and the settlement of the improved ground has been monitored rising the magnetic extensometer.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.51-56
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• 2004

The sand compaction pile (SCP) method, which forms a composite ground by driving sand piles into clay deposit, is the most commonly used soil improvement techniques in many countries for more than 30 years. Installation of sand compaction piles reduces the amount of consolidation settlement and increases the bearing capacity of soft clay deposit. In this paper, field survey conducted to investigated the consolidation behavior of the composite ground improved by SCPs. It is suggested that the measured consolidation velocity is later than design theory, however measured consolidation settlement is higher than design theory.