• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.273-276
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• 2005

Packing characteristics of amorphous alloy particles were investigated by scanning electron microscopy, compositional analysis, micro-hardness test and finite element method (FEM). Electroless Ni-plating was made on the surface of the Cu-based amorphous particles before consolidation in ambient atmosphere at an intermediate region of glass transition and crystallization temperatures $(T_g\;and\;T_x)$. Some parts of the Ni-layer in the interfaces of the consolidated particles disappeared, while some of them still remained without appreciable change in compositions. No cracks or fractures were found in the particles, which may occur at low temperatures below or near $T_g$ as anticipated by the FEM analysis. Crystallization and change in hardness were not observed after consolidation.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1204-1211
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• 2008

Compression index is one of the important characteristic numbers in soft soil engineering. Since 1940's, many researchers have suggested various practical solutions to define the compression index of clay using other soil properties. But, these results are only can give us an outline of soft soil behavior. In this study, the relationships between pore water pressure dissipation test results and compression index were suggested using comparison results of both tests. This relationships are based on basic concept of consolidation phenomena, essential difference between pore water pressure dissipation test and consolidation test, and disagreements between theoretical time factor and real time factor. To identify proportional factor of proposed equation, Geotechnical investigation results of Kwang-Yang(KY) site and Busan New Port(BN) site were used. The proportional factor was 0.0031 from 20 to 50% of consolidation rate where correlation parameter($R^2$) is 0.9051.

• Proceedings of the KAIS Fall Conference
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• 2004.06a
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• pp.39-41
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• 2004

The engineering properties of the geomaterial, an essential material in construction engineering, are significantly influenced by consolidation mode, which is called inherent anisotropy. Speically cohesive soils feature the anisotropy mainly due to their flate-like minerals and chemical interactions. In this research, an experimental study was conducted for the investigation of the anisoropy. Three isotropic and four anisotropic consolidated-undrained triaxial compression tests were performed for the cohesive specimens with various stress ratios of consolidation. The effects of the consolidation mode for cohesive soils were presented and investigated in stress-strain behavior, pore water pressure, and undrained shear strength of the test results.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.3
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• pp.183-193
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• 1987

After clay particles have been sedimented isotropically, the clay deposits have been consolidated under $K_0$-stress system. Therefore, in order to predict the behavior in-situ of normally consolidated clays, the effect of $K_0$-consolidation should be considered. A series of undrained and drained triaxial compression tests was performed on remolded specimens of clay consolidated under both $K_0$-and isotropic stress systems and the effect of $K_0$-consolidation was investigated. $K_0$-consolidation has much effect on the deviator stress, especially at initial deformation stage of consolidated-undrained tests, but has little effect on the principal effective stress ratio. Thus, the undrained strength behavior of $K_0$-consolidated samples can not be predicted from isotropically consolidated test data. However, the failure envelop, provided by the maximum principal effective stress ratio failure criterion, is unique and curved.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2000.09a
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• pp.105-115
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• 2000

As large underground projects such as radioactive waste disposal, hot water and heat storage, and geothermal energy become influential, the study, which consider all aspects of thermics, hydraulics and mechanics would be needed. Thermo Hydro-Mechanical coupling analysis is one of the most complex numerical technique because it should be implemented with the combined three governing equations to analyze the behavior of rock mass. In this study, finite element code, which is based on Biot's consolidation theory, was developed to analyze the thermo-hydro-mechanical coupling in continuum rock mass. To verify the implemented program, one-dimensional consolidation model under the isothermal and non-isothermal conditions was analyzed and was compared with the analytic solution. The parametric study on two-dimensional consolidation was also performed and the effects of several factors such as poisson's ratio and hydraulic anisotropy on rock mass behavior were investigated. In the future, this program would be revised to be used for analysis of general discontinuous media with incorporating discrete joint model.

• Tunnel and Underground Space
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• v.10 no.3
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• pp.355-365
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• 2000

As large underground projects such as radioactive waste disposal, hot water and heat storage, and geothermal energy become influential, the study, which consider all aspects of thermics, hydraulics and mechanics would be needed. Thermo-Hydro-Mechanical coupling analysis is one of the most complex numerical technique because it should be implemented with the combined three governing equations to analyze the behavior of rock mass. In this study, finite element code, which is based on Biot's consolidation theory, was developed to analyze the thermo-hydro-mechanical coupling in continuum rock mass. To verify the implemented program, one-dimensional consolidation model under the isothermal and non-isothermal conditions was analyzed and was compared with the analytic solution. The parametric study on two-dimensional consolidation was also performed and the effects of several factors such as poisson's ratio and hydraulic anisotropy on rock mass behavior were investigated. In the future, this program would be revised to be used for analysis of general discontinuous media with incorporating discrete joint model.

• Journal of the Korean Geotechnical Society
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• v.15 no.3
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• pp.3-16
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• 1999

A series of model tests was conducted to investigate the one-dimensional consolidation behavior of an improved ground where sand compaction piles(SCP) were either fully or partly installed in the model clay ground. In order to check the one-dimensional consolidation settlement and stress concentration ratios, earth pressure, pore pressure transducers and dial gauges were installed in the model clay ground. The test results revealed that the consolidation settlement of the partly penetrated SCP ground was larger than that of the fully penetrated SCP ground, and the stress concentration ratios (m) of the fully penetrated SCP ground were higher than these of the partly penetrated SCP ground. The stress concentration ratio was decreasing with the increase in the penetration depth of SCP.

• Journal of the Korean Geotechnical Society
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• v.38 no.8
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• pp.29-37
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• 2022

A three-dimensional analysis is required to interpret the drainage behavior of an improved ground with vertical drains, and the macroelement method enables efficient interpretation considering the three-dimensional drainage effect of vertical drains under two-dimensional plane strain condition. In this study, a novel finite element analysis program was developed by applying the macroelement method to the vacuum consolidation method used in ground improvement practice. The conventional macroelement method was used to calculate the amount of drainage from the vertical drain by setting the excess porewater pressure in the drainage material to zero; however, the program developed in this study was improved to consider negative excess porewater pressure as an actual vacuum consolidation condition. To verify the performance of the program, because of a comparison with the measurement values at the site where the vacuum consolidation method was applied, results predicted by the program and field measurement data showed similar settlement behavior.

• Journal of the Korean Geotechnical Society
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• v.39 no.9
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• pp.25-33
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• 2023

To effectively improve soft soils, it is necessary to perform ground behavior characteristics and stability management through measurement activities when embankment of structures on soft soils is conducted. However, there are many differences between the actual ground behavior and the initial design plan. To address this issue, this study analyzed the measured settlement in the Yeongam-Haenam areas using the Hyperbolic method to predict the settlement based on the measurement data. From the completion time of the embankment in the target area, the final settlement was predicted through the change in the degree of consolidation by the measurement period. Furthermore, the final settlement according to the change in degree of consolidation was compared and analyzed through finite element analysis and field measurement.

• Journal of Powder Materials
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• v.15 no.3
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• pp.214-220
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• 2008

In this study, consolidation behavior and hardness of commercially available molybdenum powder were investigated. In order to analyze compaction response of the powders, the elastoplastic constitutive equation based on the yield function by Shima and Oyane was applied to predict the compact density under uniaxial pressure from 100MPa to 700MPa. The compacts were sintered at $1400-1600^{\circ}C$ for 20-60 min. The sintered density and grain size of molybdenum were increased with increasing the compacting pressure and processing temperature and time. The constitutive equation, proposed by Kwon and Kim, was applied to simulate the creep densification rate and grain growth of molybdenum powder compacts. The calculated results were compared with experimental data for the powders. The effects of the porosity and grain size on the hardness of the specimens were explained based on the modified plasticity theory of porous material and Hall-Petch type equation.