• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.03a
• /
• pp.318-326
• /
• 2008

Recently, a new seismic probe, called "MudFork", has been developed and can be utilized for accurate and easy measurements of shear wave velocities of soft soils. To expand its use to estimate undrained shear strength and density, correlations between those and shear wave velocity were being attempted. Cone penetration tests and a seismic test, using MudFork, were performed at a soft ground site near Incheon, Korea. Also, undisturbed samples were obtained and shear wave velocities of the samples were measured as well as undrained shear strength, using triaxial compression test and bender elements. A simple linear relationship between shear strength and shear wave velocity was obtained, and a tentative relationship between density and shear wave velocity was also defined.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.03a
• /
• pp.673-678
• /
• 2010

In this paper, the limit load of granular materials was evaluated considering unsaturated shear strength. The unsaturated shear strength parameters were estimated using the results from triaxial compression test and soil-water characteristic curves test. In addition, the limit load of different rates of materials was compared. Also, two important design parameters, yield and failure load were defined utilizing 2-D nonlinear finite element analysis respectively.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.03a
• /
• pp.1313-1323
• /
• 2008

The purpose of this study is to understand behaviors of slopes and determine soil parameters of slopes through the triaxial compression test and the direct shear test. Following results were obtained by comparing and analyzing model tests and analysis programs of slope stability. The safety factors of the Bishop's simple method, the Morgenstern Price method, the Spencer method and the GLE method were similar to each other but safety factors of the Fellenius method and the Janbu method were different from the formers. It was found that the Bishop's simple method, the Morgenstern Price method, the Spencer method and the GLE method could be used for design but attention should be paid to the Fellenius method and the Janbu method since they underestimated safety factor.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2000.11a
• /
• pp.3-14
• /
• 2000

Anisotropic consolidation, shear, a transportational component during or after deposition each may produce anisotropic fabrics, which result in the anisotropic properties of soils. Nevertheless, the isotropically consolidated compression triaxial tests are commonly used in practice to determine the strength of the anisotropically consolidated soils because of their practicality and simplicity. In this paper the effects of anisotropic consolidation on the strength properties of soils are discussed. For the sandy soils consolidated under a constant vertical consolidation pressure, the deformation modulus decreases with decreasing consolidation pressure ratio($\sigma$$\sub$3c/'/$\sigma$ sub 1c/'), but the liquefaction resistance increases. For the saturated cohesive soils, both the undrained shear strength and undrained creep strength decrese with decreasing the consolidation pressure ratio. When the in-situ strength properties of the anisotropically and normally consolidated soils are determined by the isotropically consolidated tests, the undrained shear strength and creep strength of saturated cohesive soils as well as the deformation modulus of sandy soils are measured to be higher than the rear in-situ values. This, therefore, could lead to a dangerous judgement in stability analysis

• Journal of the Korean Geotechnical Society
• /
• v.15 no.5
• /
• pp.43-55
• /
• 1999

This study evaluated Yasufuku's constitutive model in terms of its capability to accurately consider the observed behavior of Iksan compacted weathered granite soil for various stress-paths. The strains calculated from the model are in reasonable agreement with those measured, but some discrepancies occur. The largest differences between measured and calculated strains occur for axial strain of proportional loading with increasing stress. Yasufuku's constitutive model can consider the observed behavior of Iksan compacted weathered granite soil with accuracy for conventional triaxial compression and for p'-constant loading with increasing stress ratio.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.3 no.3
• /
• pp.1-7
• /
• 2000

The aim of the work described in this paper is to study the shear characteristics of the weathered granite soil. To this end, a series of consolidated undrained triaxial compression tests are carried out to investigate the shear parameters-cohesion and internal friction angle for the degree of saturation and degree of weathering. From the results, it is found that the shear parameters of weathered granite soil are influenced on the degree of saturation, degree of weathering and disturbance. Especially, internal friction angle is more influenced on the upper factors than cohesion. And shear parameters are more acted on the degree of saturation than the degree of weathering in the test range. It is, therefore, recommended that must be considered the conditions of granite soil-degree of saturation, degree of weathering and disturbance etc-in case of the calculation of bearing capacity, stability analysis and other designs with shear parameters.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2000.04a
• /
• pp.17-20
• /
• 2000

Polymeric foams are excellent energy absorber and have found a wide range of applications especially in the automotive industry. The purpose of the present study is to develop experimental and theoretical methodology to characterize the pressure dependent yield behavior of polymeric foams. For the compression test in a triaxial stress sate a specially designed device was placed in a press machine to produce and control oil pressure. From the experiment results it was observed that the size of Mother circles is changed with mean normal stress in contrast to general metal. Then the Coulomb-Mohr criterion was applied to the data.

• Geotechnical Engineering
• /
• v.4 no.2
• /
• pp.45-55
• /
• 1988

Chemical grouting is one of the ground.improvement methods for the purpose of cutting o($\boxUl$ water and increasing the strength of soil. It has ben reported that the effect of strength increasement of groued roils is due to increase of cohesion. In this study, the effect of cohesion on the shearing resistance of grouted soil 9.as intr.estigated tall.ouch triaxial compression test. According to the result of this research, It is found that the improved cohesion increases rapidly up to the maximum value at a small strain and subsequent decrease of cohericn is due to the breaking of grout chemical at a larger strain.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.28 no.8 s.227
• /
• pp.1140-1151
• /
• 2004

This paper reports on the finite elements analysis for die compaction process of cemented carbide tool parts. Experimental data were obtained under die compaction and triaxial compression with various loading conditions. The elastoplastic constitutive equations based on the yield function of Shima and Oyane were implemented into an explicit finite element program (ABAQUS/Explicit) and implicit finite element program (PMsolver/Compaction-3D) to simulate compaction response of cemented carbide powder during die compaction. For simulation of die compaction, the material parameters for Shima and Oyane model were obtained by uniaxial die compaction test. Explicit finite element results were compared with implicit results for cemented carbide powder.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.3
• /
• pp.615-619
• /
• 2007

In this study, the MCC(modified Cam-Clay) model and the Hvorslev-MCC model, recently developed based on the critical state theory and with relatively few model parameters, were investigated by comparing the model predictions with the result of the conventional triaxial compression test strictly performed in laboratory. The discrepancy of the prediction capacities of the models exists on the heavily over-consolidated specimen. The Hvorslev-MCC model accurately predicts the peak strength envelope for heavily over-consolidated clayey specimens on the dry side of the critical state since it adopts the Hvorslev surface in the supercritical region other than the ellipse of the MCC model.