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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Geotechnical Society
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Journal DOI :
Korean Geotechical Society
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Volume & Issues
Volume 23, Issue 12 - Dec 2007
Volume 23, Issue 11 - Nov 2007
Volume 23, Issue 10 - Oct 2007
Volume 23, Issue 9 - Sep 2007
Volume 23, Issue 8 - Aug 2007
Volume 23, Issue 7 - Jul 2007
Volume 23, Issue 6 - Jun 2007
Volume 23, Issue 5 - May 2007
Volume 23, Issue 4 - Apr 2007
Volume 23, Issue 3 - Mar 2007
Volume 23, Issue 2 - Feb 2007
Volume 23, Issue 1 - Jan 2007
Selecting the target year
Performance of IPS Earth Retention System in Soft Clay
Kim, Nak-Kyung ; Park, Jong-Sik ; Oh, Hee-Jin ; Han, Man-Yop ; Kim, Moon-Young ; Kim, Sung-Bo ;
Journal of the Korean Geotechnical Society, volume 23, issue 3, 2007, Pages 5~13
The performance of innovative prestressed support (IPS) earth retention system applied in soft clay was investigated and presented. The IPS wale system provides a high flexural stiffness to resist the bending by lateral earth pressure, and transfers lateral earth pressure to strut supports. The IPS wale system provides a larger spacing of support than conventional braced and anchored systems. The IPS earth retention system was selected for temporary earth support in a building construction in North Busan area. The excavation was made 28.8 m wide, 52.0 m long, and 16.1 m deep through loose fill to soft clay. The IPS system consists of 650 mm thick slurry walls, and five levels of IPS wales and struts. Field monitoring data were collected including wall deflections at six locations, ground water levels at four locations, IPS wale deflections at thirty locations, and axial loads on struts at twenty locations, during construction. The IPS earth retention system applied in soft clay performed successfully within a designed criterion. Field measurements were compared with design assumptions of the IPS earth retention system. The applicability and stability of the IPS earth retention system in soft clay were investigated and evaluated.
Effect of Stress-Dependent Modulus and Poisson's Ratio on Rutting Prediction in Unbound Pavement Foundations
Park, Seong-Wan ;
Journal of the Korean Geotechnical Society, volume 23, issue 3, 2007, Pages 15~24
This paper will present a simple approach (or predicting layer deformation of unbound pavement materials with stress-dependent material properties. The approach is based on an uncoupled formulation in which the resilient and deformation response of unbound materials are considered separately. As a result, an uncoupled approach incorporating a resilient stiffness and Poisson's ratio model is able to simulate field measured deformation in pavement foundations. In addition, a sensitivity analysis is conducted to identify the significant factors in the stress-dependent modulus and Poison's ratio model. The predicted trends of deformation from this analysis are presented and discussed.
Variation of Earth Pressure Acting on the Cut-and-Cover Tunnel Lining due to Geotextile Mat Reinforcement
Bautista, F.E. ; Park, Lee-Keun ; Im, Jong-Chul ; Joo, In-Gon ;
Journal of the Korean Geotechnical Society, volume 23, issue 3, 2007, Pages 25~40
Excessive earth pressure is one of the major mechanical factors in the deformation and damage of Cut-and-Cover Tunnel lining in shallow tunnels and portals of mountain tunnels (Kim, 2000). Excessive earth pressure may be attributed to insufficient compaction and consolidation of backfill material due to self-weight, precipitation and vibration caused by traffic (Komiya et al., 2000; Taylor et al., 1984; Yoo, 1997). Even though there were a lot of tests performed to determine the earth pressure acting on the tunnel lining, unfortunately there were almost no case histories of studies performed to determine remedial measures that reduce differential settlement and excessive earth pressure. In this study the installation of geotextile mat was selected to reduce the differential settlement and excessive earth pressure acting on the cut-and-cover tunnel lining. In order to determine settlement and earth pressure reduction effect (reinforcement effect) of geotextile mat reinforcement, laboratory tunnel model tests were performed. This study was limited to the modeling of rigid circular cut-and-cover tunnel constructed at a depth of
in loose sandy ground and subjected to a vibration frequency of 100 Hz. Model tests with varying soil cover, mat reinforcement scheme and slope roughness were performed to determine the most effective mat reinforcement scheme. Slope roughness was adjusted by attaching sandpaper #100, #400 and acetate on the cut slope surface. Mat reinforcement effect of each mat reinforcement scheme were presented by the comparison of earth pressure obtained from the unreinforced and mat reinforced model tests. Soil settlement reduction was analyzed and presented using the Picture Analysis Method (Park, 2003).
Characteristics of Shear Behavior of Remolded Nak-dong River Sandy Silt
Kim Young-Su ; Tint Khin Swe ; Kim Dae-Man ;
Journal of the Korean Geotechnical Society, volume 23, issue 3, 2007, Pages 41~50
The results from normally consolidated isotropic drained and undrained triaxial compression tests (NCIU and NCID) on sand with high silt content were presented in this paper. The experiments were performed on specimens of Nak-dong River sand with 63% silt content under effective confined pressures, 100 kPa to 400 kPa. From test results, Sandy silt became initially compressive but eventually appeared to provide dilatancy response throughout the entire stress-strain curve The behavior of sandy silt was more difficult to characterize than that of clay and sand due to lower plastic characteristic. Especially, the samples exhibited dilatancy development during shear after failure. The shear behavior and shear strength parameters of sandy silt can be determined as stress-strain behaviors are described by the Mohr-Coulomb failure criterion. The shear behaviors were observed increasing dilatancy volume change tendency with strain-softening tendency after failure. In this paper, the behavior of dilatancy depends on not only sand content but also fine content with low-cohesion during shear in the samples of sandy silt.
Reliability Analysis of Slope Stability with Sampling Related Uncertainty
Kim, Jin-Man ;
Journal of the Korean Geotechnical Society, volume 23, issue 3, 2007, Pages 51~59
A reliability-based approach that can systematically model various sources of uncertainty is presented in the context of slope stability. Expressions for characterization of soil properties are developed in order to incorporate sampling errors, spatial variability and its effect of spatial averaging. Reliability analyses of slope stability with different statistical representations of soil properties show that the incorporation of sampling error, spatial correlation, and conditional simulation leads to significantly lower probability of failure than that obtained by using simple random variable approach. The results strongly suggest that the spatial variability and sampling error have to be properly incorporated in slope stability analysis.
Comparative Study between Design Methods and Pile Load Tests for Bearing Capacity of Driven PHC Piles in the Nakdong River Delta
Dung, N.T. ; Chung, S.G. ; Kim, S.R. ; Chung, J.G. ;
Journal of the Korean Geotechnical Society, volume 23, issue 3, 2007, Pages 61~75
Deep foundations have been popularly installed in hard stratum such as gravels or rocks in Korea. However, it is necessary to consider sand or sandy gravel layers that locate at the mid-depths as the bearing stratum of piles in the thick Nakdong River deltaic deposits, as done in the Chaophraya (Bangkok) and Mississippi River deltas. This study was focused on the finding of suitable methods for estimating bearing capacity when driving prestressed high-strength concrete (PHC) piles to a required depth in the deltaic area. Ground investigation was performed at five locations of two sites in the deltaic area. Bearing capacity of the driven piles has been computed using a number of proposed methods such as CPT-based and other analytical methods, based on the ground investigation and comparison one another other. Five PDA (pile driving analyzer) tests were systematically carried out at the whole depths of embedded piles, which is a well-blown useful technique for the purposes. As the results, the bearing capacities calculated by various methods were compared with the PDA and static load testing results. It was found that the shaft resistance is significantly governed by set-up effects and then the long-term value agrees well with that of the
method. Also, the design methods for toe resistance were determined based on the SLT result, rather than PDA results that led to underestimation. Moreover, using the CPT results, appropriate methods were proposed for calculating the bearing capacity of the piles in the area.
Elastic-plastic Micromechanics Modeling of Cross-anisotropic Granular Soils: I. Formulation
Jung, Young-Hoon ; Chung, Choong-Ki ;
Journal of the Korean Geotechnical Society, volume 23, issue 3, 2007, Pages 77~88
A micromechanics-based model to simulate the elastic and elastic-plastic behavior of granular soils is developed. The model accounts for the fabric anisotropy represented by the statistical parameter of the spatial distribution of contact normals, the evolution of fabric anisotropy as a function of stress ratio, the continuous change of the co-ordination number relating to the void ratio, and the elastic and elastic-plastic microscopic contact stiffness. Using the experimental data for metallic materials, the elastic-plastic contact stiffness is derived as a power function of the normal contact force as well as the contact force initiating the yielding of contact bodies. To quantitatively assess microscopic model parameters, approximate solutions of cross-anisotropic elastic moduli are derived in terms of the micromechanical parameters.
Elastic-plastic Micromechanics Modeling of Cross-anisotropic Granular Soils: II. Micromechanics Analysis
Jung, Young-Hoon ; Chung, Choong-Ki ;
Journal of the Korean Geotechnical Society, volume 23, issue 3, 2007, Pages 89~100
In the companion paper, we provided the novel elastic-plastic constitutive model based on the micromechanics theory. Herein, the elastic and elastic-plastic deformation of granular soils is meticulously analyzed. To guarantee high accuracy of the microscopic parameter, the systematic procedure to evaluate the parameters is provided. The analysis of the elastic response during the isotropic and triaxial compression shows that the stress-level dependency of cross-anisotropic elastic moduli is induced by the power relationship of the contact force in the normal contact stiffness, while the evolution of fabric anisotropy is more pronounced during triaxial compression. The micromechanical analysis indicates that the plastic strains are likely to occur at very small strains. The plastic deformation of tangential contacts has an important role in the reduction of soil stiffness during axial loading.
Effect of Fines on the Stability of Unsaturated Soil Slopes
Lee, Kyu-Hyun ; Jeong, Sang-Seom ; Kim, Tae-Hyung ;
Journal of the Korean Geotechnical Society, volume 23, issue 3, 2007, Pages 101~109
In South Korea, many weathered soil slopes are composed of soil mixtures with certain amount of clay fractions in natural soil deposits. Accordingly, it is very important to analyze that effect of the fines on the stability of unsaturated soil slopes. In this study, five different soil types classified by mixture portion of fines were used and experiment on the soil-water characteristic curve tests (SWCC) using GCTS (Geotechnical Consulting and Testing Systems) pressure plate were performed in order to analyze the stability of unsaturated soil slopes. Based on the infiltration analysis which contains SWCC test result by the SEEP/W, it is shown that the increasing rate of the wetting band depth was decreased as the fines content and the relative density were increased. According to the stability analysis result of the unsaturated soil slopes through the SLOPE/W, it is found that the transition from the wetting band depth to the variation of strength parameters which affect the stability of unsaturated soil slopes appears to occur around
of clay contents in the mixtures.
Reliability Analysis of Seismically Induced Slope Deformations
Kim, Jin-Man ;
Journal of the Korean Geotechnical Society, volume 23, issue 3, 2007, Pages 111~121
The paper presents a reliability-based method that can capture the impact of uncertainty of seismic loadings. The proposed method incorporates probabilistic concepts into the classical limit equilibrium and the Newmark-type deformation techniques. The risk of damage is then computed by Monte Carlo simulation. Random process and RMS hazard method are introduced to produce seismic motions and also to use them in the seismic slope analyses. The geotechnical variability and sampling errors are also considered. The results of reliability analyses indicate that in a highly seismically active region, characterization of earthquake hazard is the more critical factor, and characterization of soil properties has a relatively small effect on the computed risk of slope failure and excessive slope deformations. The results can be applicable to both circular and non-circular slip surface failure modes.
Relationship between the State Parameter and Cone Resistance of Busan Sand
Kim, Seung-Han ; Lee, Moon-Joo ; Choi, Sung-Kun ; Hong, Sung-Jin ; Lee, Woo-Jin ;
Journal of the Korean Geotechnical Society, volume 23, issue 3, 2007, Pages 123~131
A series of CIDC triaxial tests and cone penetration tests in calibration chamber were performed to investigate the relationship between state parameter and normalized cone resistance far dredged Busan sand. From the results of the triaxial tests, the critical state line of Busan sand was established, and the critical state parameters found to be
. By analyzing the state parameters and corresponding cone resistances for calibration chamber specimens, the relationship between normalized cone resistance and state parameter for Busan sand was defined as
. This relationship was also shown to be independent of the stress history. From the comparison of the slope of the normalized cone resistance, m, and the normalized cone resistance at
, with those of various sandy soils from over the world, the relationship of m and
of Busan sand was concluded to show a good agreement with the result published previously, while Busan sand had the largest
among the soils with similar
Case Studies of Penetration Characteristics of DCM Wall Using Spiral Mixing Blades in Soil Layers
Jung, Doo-Hoi ; Jeong, Gyung-Hwan ; Yang, Tae-Seon ;
Journal of the Korean Geotechnical Society, volume 23, issue 3, 2007, Pages 133~140
DCM (Deep Cement Mixing Method) has been applied to build structures such as self-supported earth retaining walls. DCM columns should be penetrability into the stiff layer to assure the self-supporting ability. On the penetration increase of blade attached to the DCM mixing tools, a spiral mixing blade has been revised. Penetration characteristics of spiral blades in the stiff soil layer were evaluated through Gimhae and Incheon areas. The spiral mixing blades could penetrate into the stiff soil layers which have the N-value of greater than 30 although the penetration rate is somewhat slow. Penetration characteristics and economical efficiency should be discussed to determine the critical depth of the spiral mixing blade because the penetration efficiency can decrease in the stiff layer in this paper.
Evaluation of the Dynamic P-Y Curves of Soil-Pile System in Liquefiable Ground
Han, Jin-Tae ; Kim, Sung-Ryul ; Kim, Myoung-Mo ;
Journal of the Korean Geotechnical Society, volume 23, issue 3, 2007, Pages 141~147
Various approaches have been developed for the dynamic response analysis of piles. In one of the approaches, the soil-pile interaction is approximated by using parallel nonlinear springs, namely the p-y curves. Currently available p-y curve recommendations are based on static and cyclic lateral load tests. Other researchers have attempted to extend the p-y curves by incorporating the effects of liquefaction on soil-pile interaction and derived scaling factors of p-y curves to account fur the liquefaction. However, opinions on the scaling factors vary. In this study, the sealing factors, which reflect the variation of the elastic moduli of surrounding soils, were established combining the relationship between excess pore pressures and the natural frequencies of a soil-pile system obtained from Ig shaking table tests and the relationship between the elastic moduli of surrounding soils and the natural frequencies of a soil-pile system obtained from numerical analyses. As a result, the scaling factors were presented in an exponential function.