• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.3
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• pp.70-81
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• 1996

Solutions of geotechnical engineering problems require predictions of deformation and stresses during various stages of loading. Powerful numerical methods are available to make such predictions even for complicated problems. To get accurate results, realistic stress-strain relationships of soils are dependent on a number of factors such as soil type, density, stress level and stress path. Attempts are continuously being made to develope analytical models for soils incorporating all such factors. Isotropic compression-expansion test and a series of drained conventional triaxial tests with several stress path for Baekma river sand were performed to investigate stress-strain and volume change characteristics of Lade's single work hardening model dependant on the stress path. In order to predicted of stress-strain and volumetric strain behavior were determined the values of parameters for the mode by the computer program based on the regression analysis. Predicted stress-strain behavior of triaxial compression tests and optional stress path tests for increasing confining pressure with parameters obtained conventional triaxial compression tests agreed with several test results but the prediction results for decreasing confining pressure reduced triaxial compression tests make a little difference with test results.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.311-318
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• 2000

In constructions of dams and ports structure, gravels are used as principle structural materials. Gravels have different material property compared with other materials like soil and concretes, etc. For example, material properties of gravels obtained from normal triaxial compression test are usually overestimated due to scale and penetration effects. Also, material properties of gravels under dynamic loads are the main interest when structural behavior of rockfill dam under earthquake loads is analyzed. The development of large triaxial compression apparatus is needed for the better estimation of material property of gravel. This paper reports work in progress to development of large triaxial compression apparatus.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.668-673
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• 2008

In this paper, we developed a physically-based micromechanical model for inelastic deformation of ceramic powders. The aggregate response of ceramic particles was modeled using the two-surface yield function which considered the shear-induced dilatancy caused by friction, rolling resistance and cohesion between powder particles and consolidation caused by plastic deformation of powder themselves under high compression. The constitutive equations were implemented into the user-subroutine VUMAT of finite element program ABAQUS/Explicit. The material parameters in the constitutive model were identified by calibrating the model to reproduce data from triaxial compression tests and simple compression tests. The density distribution obtained by using the proposed model was in good quantitative agreement with the experimental results of the triaxial compression and cold isostaic compression as well.

• Geotechnical Engineering
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• v.12 no.2
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• pp.9-18
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• 1996

The results of a series of triaxial compression tests on remolded normally consolidated clay are compared with the predictions .by the isotropic single -hardening constitutive model, which incorporates eleven parameters. The parameters can be determined from undrained triaxial compression tests on isotropically consolidated specimens of remolded clay. The model with the determined parameters is applied to predict the stress-strain and pore pressure behaviors for untrained triaxial compresion tests on anisotropically consolidated specimens. Also the model is utilized to predict the stress strain and voltmetric strain behavior for drained triaxial compression tests on both isotropic and anisotropic specimens. The predicted response agrees well with the measured behavior for undrained triaxial compression tests on not only isotropically but also anisotroically but also anisotropically consolidated specimens. The initial volumetric strain is, however, predicted to be less than the measured value from drained triaxial compression tests, while the predicted volumetric strain close to failure is greater than the measured value. Nevertheless, it may be stated generally that overall acceptable predictions are produced. Therefore, the results of this study indicate that the applicability of the model on prediction of the behavior of normally consolidated clay is achieved sufficiently.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.02a
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• pp.71-78
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• 2000

SHANSEP method involves the consolidation to stresses in excess of the preconsolidation pressure in order to overcome sample disturbance effect. The concept of SHANSEP is based on an approach to laboratory test which attempts to reproduce the in-situ conditions more closely than is possible in routine tests and evaluates normalized strength parameters for the soil as a function of OCR. But SHANSEP method can be applied only to fairly uniform clay deposits, and is unsuitable for a random deposit. In this study, CK/sub o/U triaxial compression test and incremental loading consolidation test were performed for the application of SHANSEP method on Yangsan clay. During the K/sub o/-consolidation, triaxial specimens were consolidated to stress equal to two times the in-situ vertical effective stress. And for overconsolidated condition, the specimens were swelled to a known vertical effective stress in order to have the desired OCR. With the results of CK/sub o/U triaxial compression test using the block samples, the relationship between c/sub u//σ/sub vc/' and OCR on Yangsan clay was established. For evaluating the undrained shear strength of Yangsan clay with depth, CK/sub o/U triaxial compression test was performed using the piston samples taken from Yangsan site. And also undrained shear strength was analyzed from the in-situ test such as Cone Penetration Test(CPT), Dilatometer Test(DMT), and Field Vane Test(FVT) and was compared with that of CK/sub o/U triaxial compression test.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.3
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• pp.947-954
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• 2014

In general, Fracture of the material is not occurring of the maximum normal stress or the maximum shear stress failure in the state. Maximum normal stress and maximum shear stress in the state of Critical coupling from being destroyed based on the Mohr-Coulomb theory. Couple of different mixtures, including permeable asphalt pavement, SMA and dense-graded asphalt mixture, were used for compression triaxial test at $45^{\circ}C$ and $60^{\circ}C$. Mohr-Coulomb theory to the analysis of compression triaxial test result of the internal friction angle $38.9^{\circ}{\sim}46.9^{\circ}$ measured somewhat irregularly, but in the case of cohesion, depending on whether the temperature and immersion of the specimen appeared differently. In addition, Indirect tensile test and compression triaxial test of the asphalt mixture to determine the correlation between compression triaxial test results assessed as cohesion and internal friction angle calculated using the theoretical Indirect tensile strength and measured indirectly tensile strength were analyzed. The Measured & Predicted IDT St values tended to be proportional.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.998-1003
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• 2008

It has been recognized unsaturated soil behaviour playing an important role in geomechanics. Up to now, only a few experimental data are available for the technical difficulties related to both volume changes and suction measurements. In this study, the volume changes of unsaturated compacted silty soil were monitored with proximeter (i.e. non-contactable transducer) during various triaxial compression tests, which gave a realistic estimation in the volume changes of unsaturated soil sample. Various triaxial compression tests for unsaturated soil under different drainage conditions are carried out. The behaviour of the pore pressure, namely, the pore-air pressure and the pore-water pressure, and matric suction during the shearing tests are investigated. The experimental results have revealed that the mechanical behaviour of unsaturated soil can be significantly affected by the matric suction.

• Journal of Ocean Engineering and Technology
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• v.25 no.3
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• pp.34-39
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• 2011

This study investigated the shear and CBR characteristics of dredge soil-bottom ash-waste tire powder-mixed lightweight soil, which was developed to recycle dredged soil, bottom ash, and waste tire powder. Test specimens were prepared with various contents of waste tire powder ranging from 0 to 100% at 50% intervals by the weight of the dry dredged soil. Several series of triaxial compression tests and CBR tests were conducted. The shear strength characteristics of the lightweight soil were compared using two different shear tests (triaxial compression test and direct shear test). The experimental results indicated that the internal friction angle of the lightweight soil obtained by the direct shear tests was greater than that by the triaxial shear tests. However, the cohesion value obtained by the triaxial shear tests was greater than that by the direct shear tests. The CBR value of the lightweight soil decreased from 35% to 15% as waste tire powder content increased.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.652-657
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• 2001

Densification behavior of aluminum alloy(A16061) powder was investigated under cold compaction. Experimental data were obtained under triaxial compression with various loading conditions. A special form of the Cap model was proposed from experimental data of A16061 powder under triaxial compression. The proposed yield function and several yield functions in the literature were implemented into a finite element program (ABAQUS) to compare with experimental data for densification behavior of A16061 powder under cold isostatic pressing and die compaction. The agreement between finite element calculations from the proposed yield function and experimental data is very good under cold isostatic pressing and die compaction.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.1
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• pp.95-104
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• 2002

Densification behavior of aluminum alloy(A16061) powder was investigated under cold compaction. Experimental data were obtained under triaxial compression with various loading conditions. A special form of the Cap model was proposed from experimental data of A16061 powder under triaxial compression. The proposed yield function and several yield functions in the literature were implemented into a finite element program (ABAQUS) to compare with experimental data for densifcation behavior of A16061 powder under cold isostatic pressing and die compaction. The agreement between finite element calculations from the proposed yield function and experimental data is very good under cold isostatic pressing and die compaction.