• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.861-866
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• 2003

While coarse geomaterials with abundant fine particles are common, comparatively little information is available to know their engineering behaviour. In this study, the effects of fine particle content of coarse geomaterials on engineering properties, such as shear strength, deformability and permeability were investigated. It was known through large triaxial compression tests that when they are compared with good rock materials, the rock materials with abundant fine particles have different compaction characteristics, low shear strength, low stiffness, and low permeability.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.198-205
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• 2003

We considered the variation of elastic wave velocity due to the anisotropy of rock materials and stress level for acoustic emission (AE) source location in cylindrical rock specimens. Elastic wave velocity and AE were measured for Keochang granite and Yeosan marble under various axial stresses and confining pressures. Partition approximation method was suggested and it was compared with the difference approximation method and the least square method.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 가을 학술발표회 논문집
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• pp.353-360
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• 2000

We developed large diameter sampler (we called KICT type large diameter sampler) to obtain undisturbed clay and sand samples. In-situ test carried out in the In-Chon international airport and Kim-Hae. Also we obtained undisturbed sample with a hydraulic piston sampler in the nearly site and carried out unconfined compression test, consolidation test and triaxial test. The result, unconfined compression strength, secant modules, preconsolidation pressure and undrained shear strength of samples to obtain KICT type large diameter sampler are larger than that of samples to obtain hydraulic piston sampler. But failure strains and volume changes at the consolidation of samples to obtain KICT type large diameter sampler are smaller than that of samples to obtain hydraulic piston sampler

• 한국지반공학회논문집
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• 제16권2호
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• pp.79-89
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• 2000

The application of stabilization method has increased because of short construction periods, no environmental problems with dumped and replaced soil, assurance of required strength and economical effect with mid to small size construction. The unconfined and triaxial(UU-condition) compression tests were executed with each mixing sample for the study of the improvement effects and the effect of design-parameters by the stabilization methods. Three typical stabilizers, which are representative in Korea, were applied in this study, and three common soils(very soft clay, general weathered soil, common clay), which are common in Korea, were used in this study. In this study, the effect of engineering factors(soils, stabilizers and water contents, etc.) which are important parameters for the improvement effects of mixed ground by stabilizers, was analyzed. As results, the tendencies of design-parameters(unconfined compression strength, deformation modulus and strength parameter) are presented and the criteria of the application of stabilization methods are suggested.

• 한국안전학회지
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• 제21권2호
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• pp.89-97
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• 2006

Recently, experimental and theoretical studies about nonlinear behavior of large concrete structures are in progress. The purpose of this study is to describe the nonlinear behavior of a concrete specimen under compression using several plastic models and to choose the best plastic model for later use in numerical analyses of concrete structures. ABAQUS is a general-purpose FEM program and we tested all suitable embedded material models for concrete. To verify the effectiveness of nonlinear analyses, results were compared with uniaxial and triaxial compression test results.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 가을 학술발표회 논문집
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• pp.673-680
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• 2002

The mechanical characteristics and compressibility of Light-Weighted Foam Soil (LWFS) are investigated. LWFS is composed of the dredged soil from offshore, cement and foam to reduce the unit-weight and increase compressive strength. For this purpose, the unconfined compression tests and triaxial compression tests are carried out on the prepared specimens of LWFS with various conditions such as initial water contents, cement contents, and confining stresses. The test results of LWFS indicated that the stress-strain relationship and the compressive strength are strongly influenced by the cement contents rather than the intial water contents of the dredged soils. In this study, the normalized factor considering the ratio of initial water contents, cement contents, and foam contents is suggested to evaluate the relationship between compressive strength and normalized factor.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.1181-1192
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• 2008

A laboratory investigation was carried out into effects of strain rate on undrained shear behavior of Holocene clay underneath Kobe Airport with an objective to evaluate the factor of safety of the retaining structure built on it. It was examined in a series of triaxial compression and extension tests performed using different rate of axial straining. A comparative compression test in which the strain rate was changed in steps was also carried out. Similar tests were performed in constant-volume direct shear box (DSB) test. And, the deformation characteristics of the clay were also examined in order to evaluate the variation of stiffness during undrained shearing. It was found that the undrained strength increased with not only the shear rate but also the consolidation period. ISOTACH properties seemed a key to govern the undrained shear behavior.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.179-180
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• 2006

Densification behavior of various metal and ceramic powder was investigated under cold compaction. The Cap model was proposed based on the parameters obtained from axial and radial deformation of sintered metal powder compacts under uniaxial compression and volumetric strain evolution. For ceramic powder, the parameters were obtained from deformation of green powder compacts under triaxial compression. The Cap model was implemented into a finite element program (ABAQUS) to compare with experimental data for densification behavior of various metal and ceramic powder under cold compaction.

• 한국지반신소재학회논문집
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• 제5권1호
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• pp.15-23
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• 2006

모래다짐말뚝 및 쇄석말뚝 공법의 경우, 연약지반의 보강, 극한지지력의 증대 및 기초지반의 압밀을 가속화시키기 위한 목적으로 지난 수십 년간 폭넓게 적용되고 있다. 쇄석말뚝공법은 비교적 강성이 크고 압축성이 작은 쇄석 등을 이용하여 다짐말뚝을 형성, 연약지반을 개량하는 공법이지만 횡방향 구속압력이 충분하게 발휘되지 않는 지반에서는 팽창파괴(bulging failure)에 대한 저항이 없어 적용이 불가능하게 된다. 따라서 본 연구에서는 쇄석말뚝의 활용도를 높이기 위해 팽창파괴 및 전단파괴 등을 방지하여 침하량을 상당부분 억제시킬 수 있는 고강도 지오그리드 보강 쇄석말뚝공법을 개발하였다. 본 공법 개발을 위해 삼축압축시험을 통하여 치환율 및 구속압력에 따른 일반적인 쇄석말뚝의 거동특성을 우선 살펴보았다. 아울러 유한요소 해석을 통한 3차원 수치해석을 시행하여 지오그리드의 종류 및 지오그리드 보강심도변화에 따른 지오그리드 보강 쇄석말뚝공법의 거동특성 및 침하저감효과를 평가함으로써 지오그리드 보강 쇄석말뚝의 적용성을 평가해 보았다.

• 한국지반공학회논문집
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• 제21권4호
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• pp.41-49
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• 2005

점토의 거동은 온도변화에 민감하기 때문에 고온이력을 받는 점토의 공학적 성질에 관한 연구가 최근 증가하고 있다. 이러한 증가 현상은 온도의 영향을 연구함으로서 점토의 거동을 지배하는 본질적인 메커니즘을 해명할 수 있고 최근 경제활동의 증가와 더불어 화학적인 지반개량, 토양 열 비축시스템 및 방사성 핵폐기물 지하처리 시스템 등 지반이 고온환경에 노출되는 기회가 증가하고 있기 때문이다. 이러한 측면에서 열 이력을 받는 점토 지반의 압밀 및 강도특성을 파악하는 것은 매우 중요하다 따라서 본 연구에서는 고온조건에 있는 점토의 역학적 거동을 삼축압축 시험을 통해 조사하였다. 구체적인 방법으로는 고온고압형 삼축압축시험기를 이용해서 압밀비배수 삼축압축시험을 $20^{\circ}C,\;50^{\circ}C,\;75^{\circ}C,\;80^{\circ}C$ 및 $100^{\circ}C$등으로 온도를 변화시켜 실온 및 고온조건에 있는 점토의 변형${\cdot}$전단강도 및 압축${\cdot}$압밀특성 등을 조사하였다.