Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Geotechnical Society
Journal Basic Information
Journal DOI :
Korean Geotechical Society
Editor in Chief :
Volume & Issues
Volume 15, Issue 6 - Dec 1999
Volume 15, Issue 5 - Oct 1999
Volume 15, Issue 4 - Aug 1999
Volume 15, Issue 3 - Jun 1999
Volume 15, Issue 2 - Apr 1999
Volume 15, Issue 1 - Feb 1999
Selecting the target year
An Experiment of Consolidation Behavior for Partly and Fully Penetrated SCP Ground
Jung, Jong-Bum ; Moriwaki, Takeo ; Lee, Kang-Il ; Kang, Kwon-Su ; Park, Byong-Kee ;
Journal of the Korean Geotechnical Society, volume 15, issue 3, 1999, Pages 3~16
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
Development of Landfill Material by Utilizing Waste Lime
Shin, Eun-Chul ; Oh, Young-In ;
Journal of the Korean Geotechnical Society, volume 15, issue 3, 1999, Pages 17~25
The feasibility of using waste lime, which is produced as a byproduct during the manufacture of sodium carbonate in Inchon, Korea. as a stabilization admixture with weathered granite soil was investigated. Laboratory tests were conducted to determine the chemical composition, pH, compaction characteristics, unconfined compression strength. X-ray diffraction analysis of waste lime and weathered granite soil admixtures. Based on the present tests, it appears that the admixtures are environmentally safe and can be used as landfill material.
Slope Failure Surface Using Finite Element Method
Ahn, Tae-Bong ;
Journal of the Korean Geotechnical Society, volume 15, issue 3, 1999, Pages 27~40
In limit equilibrium methods(LEM), all methods employ the same definition of the safety factor as a ratio of the shear strength of the soil to the shear stress required for equilibrium, employing certain assumptions with regard to equilibrium. In addition, in the conventional finite element method of analysis, the minimum safety factor is obtained assuming certain slip surfaces after the state of stress are found. Although the stress states are obtained from the finite element method(FEM), the slope stability analysis follows the conventional method that assumes a potential slip surface. In this study, a slope stability analysis based on FEM is developed to locate the slip surface by tracking the weakest points in the slope based on the local safety factor considering the magnitude and direction of the shear stresses. It has also been applied to be compared with the slip surfaces predicted by LEM. A computer program has been developed to draw contour lines of the local safety factors automatically. This method is illustrated through a simple hypothetical slope, a natural soil slope, and a dam slope. The developed method matches very well with the conventional LEM methods, with slightly lower global safety factors.
A Study on Stability Evaluation of the Nail-Anchor Mixed Support System
Kim, Hong-Taek ; Cho, Yong-Kwon ; Yoo, Han-Kyu ;
Journal of the Korean Geotechnical Society, volume 15, issue 3, 1999, Pages 41~70
The benefits of utilizing internal reinforced members, such as soil nails and ground anchors, in maintaining stable excavations and slopes have been known among geotechnical engineers to be very effective. Occasionally, however, both soil nails and ground anchors are simultaneously used in one excavation site. In the present study, a method of limit equilibrium stability analysis of the excavation zone reinforced with the vertically or horizontally mixed nail-anchor system is proposed to evaluate the global safety factor with respect to a sliding failure. The postulated failure wedges are determined based on the results of the
program analyses. This study also deals with a determination of the required thickness of the shotcrete facing. An excessive facing thickness may be required due to both the stress concentration and the relative displacement at the interface zone between the soil nailing system and the ground anchor system. A simple finite element method of analysis is presented to estimate the corresponding relative displacement at the interface zone between two different support systems. As an efficient resolution to reduce the facing thickness, the modified bearing plate system is also proposed. Finally with various analysis related to the effects of design parameters, the predicted displacements are compared with the results of the
Undrained Behavior of Clay-Sand Mixtures under Triaxial Loading
Shin, Joon-Ho ; Jeong, Sang-Seom ;
Journal of the Korean Geotechnical Society, volume 15, issue 3, 1999, Pages 71~81
A study on the undrained behavior of isotropically consolidated clay-sand mixtures was carried out using the automated triaxial testing apparatus. Overconsolidated ratio, effective mean pressure and clay content( up to 20% bentonite) were the factors varied in the experimental investigation. Undrained behavior(strength and pore water pressure generation during shear in triaxial loading) depends upon overconsolidation ratio, confining pressure and clay content. Significant changes in undrained compression characteristics occurred at around 20% of clay contents in the sand. The test results were analyzed and their behaviors were interpreted within the framework of plasticity constitutive model for clay-sand mixtures. Possible physical bases for the proposed forms are discussed. Validation of the applied model using the laboratory results is also given.
Interaction between Flexible Buried Pipe and Surface Load
Yoo, Chung-Sik ; Chung, Suk-Won ; Lee, Kwang-Myung ; Kim, Joo-Suk ;
Journal of the Korean Geotechnical Society, volume 15, issue 3, 1999, Pages 83~97
This paper presents the results of a parametric study on the interaction between buried pipes and surface load using the finite element method of analysis. A series of laboratory model tests were also performed in order to validate the adopted finite element model and to capture essential features of the physical behavior of buried pipes subjected to surface load. In the parametric study, a wide range of boundary conditions were analyzed with emphasis on the response of the buried pipes to surface load. The results of analysis such as contact stress distribution at the soil/pipe interface and axial thrust of the pipe were thoroughly analyzed, and a database on the response of buried pipe under surface load was established for future development of a semi-empirical design/analysis method. The results indicated that the degree of interaction between buried pipes and surface load significantly varies with the vertical and lateral location of pipe with respect to surface load, and that the current design method, which does not consider soil-structure interaction, cannot correctly capture the pipe response to surface loading. Furthermore, based on the results of analysis, a semi-empirical equation was suggested, which estimates the maximum pipe thrust due to surface load for flexible buried pipes.
An Experimental Study on the Bearing Characteristics of Auger-Cast Pile Installed Using Expansive Mortar
Yoon, Sung-Soo ; Lee, Won-Je ; Lee, Woo-Jin ;
Journal of the Korean Geotechnical Society, volume 15, issue 3, 1999, Pages 99~111
The frictional capacity of auger-cast piles is often very small because of the disturbance of the soil surrounding the pile during the excavation process. Usage of expansive agents and a pressurized injection technique for auger-cast piles should improve the frictional resistance between pile and soil. This paper presents the test results of auger-cast model piles installed with expansive mortar in laboratory compacted weathered soil. The model piles were installed in a calibration chamber with a variation in the amount of expansive agent, the injection process and the chamber pressure. It was observed that the pile shaft resistance increases with the increased amount of expansive agent, and also increases when mortar is pressure injected. The shaft resistance increased up to 24% for the pile installed only with expansive mortar and increased up to 56% for the pile installed with the pressurized injection of expansive mortar, compared with that of piles with plain mortar.
Evaluation of the Sequential Behavior of Tieback Wall in Sand by Small Scale Model Tests
Seo, Dong-Hee ; Chang, Buhm-Soo ; Jeong, Sang-Seom ; Kim, Soo-Il ;
Journal of the Korean Geotechnical Society, volume 15, issue 3, 1999, Pages 113~129
In this study, a total of 12 types of sequential model tests were conducted at the laboratory for small scale anchored walls. The sequential behavior for flexible wall embedded in sand was investigated by varying degrees of relative density of Joomoonjin sand and flexibility number of model wall. The model tests were carried out in a 1000mm width, 1500mm length, and 1000mm high steel box. Load cells, pressure cells, displacement transducer and dial gauges were used to measure the anchor forces, lateral wall deflections, lateral earth pressures and vertical displacements of ground surface, respectively. Limited model tests were performed to examine the parameters for soil-wall interaction model and the formulation of analytical method was revised in order to predict the behavior of anchored wall in sand. Based on the model tests and proposed analytical method, model simulations were performed and the predictions by the present approach were compared with measurements by the model tests and predictions by other commercial programs. It is shown that the prediction by the present approach simulates qualitatively well the general trend observed for model test.
Quantification of Surface Topography Using Digital Image Analysis
Lee, Seok-Won ;
Journal of the Korean Geotechnical Society, volume 15, issue 3, 1999, Pages 131~149
It was found that surface roughness has a first-order effect on the interface shear strength and accordingly it should be accurately quantified if its role is to be properly understood. To quantify the surface topography, first of all, a variety of commonly used surface roughness parameters and profiling methods were reviewed in this study. Based on this review, the normalized roughness parameter.
(Uesugi and Kishida, 1986), the profile roughness parameter,
, and the surface roughness parameter,
(Dove and Frost, 1996), were selected to be appropriate candidates of roughness parameters and the digital image analysis based Optical Profile Microscopy(OPM) method(Dove and Frost, 1996) to be an appropriate profiling method for this study. Using a smooth and three textured HDPE geomembranes which encompass the range of textures and texture patterns commonly used, a series of roughness measurements on virgin and previously used geomembranes were performed. The results showed that both
values appropriately reflect the degree of texturing for the geomembranes used in this study, however,
value showed limited ranges of variation which may not be sufficient to permit distinction between roughness values for certain conditions. The results of this study will be extended to the investigation of the influence of surface roughness on interface strength in future study.
Numerical Predictions of the Load-Displacement Curves of Rock-Socketed Concrete Piles
Kwon, Oh-Sung ; Kim, Jeong-Hwan ; Jeon, Kyung-Soo ; Kim, Myoung-Mo ;
Journal of the Korean Geotechnical Society, volume 15, issue 3, 1999, Pages 151~160
The settlement limit concept is generally adopted as design criteria of rock-socketed pile foundations, therefore, the load-displacement
behavior of the rock-socketed piles should be well understood at the design stage, which, however, is hard to achieve due to its complexity. To help this out, field pile load tests are executed on cast-in-situ concrete piles, first, to figure out the
behavior of rock-socketed piles. Next, the
relations of the piles are simulated numerically using commercial package program(ELAC) varying a couple of input data which are sensitive in shaping the
curves. Finally, the relation between the best input data for the numerical simulations and the geotechnical field data are cultivated to generalize the numerical simulation procedures, which enables geotechnical engineers to predict the
behavior at the design stage, if appropriate geotechnical field data are provided.
Modeling the Effect of Water, Excavation Sequence and Reinforcement on the Response of Tunnels
Kim, Yong-Il ;
Journal of the Korean Geotechnical Society, volume 15, issue 3, 1999, Pages 161~176
A powerful numerical method that can be used for modeling rock-structure interaction is the Discontinuous Deformation Analysis (D D A) method developed by Shi in 1988. In this method, rock masses are treated as systems of finite and deformable blocks. Large rock mass deformations and block movements are allowed. Although various extensions of the D D A method have been proposed in the literature, the method is not capable of modeling water-block interaction, sequential loading or unloading and rock reinforcement; three features that are needed when modeling surface or underground excavation in fractured rock. This paper presents three new extensions to the D D A method. The extensions consist of hydro-mechanical coupling between rock blocks and steady water flow in fractures, sequential loading or unloading, and rock reinforcement by rockbolts, shotcrete or concrete lining. Examples of application of the D D A method with the new extensions are presented. Simulations of the underground excavation of the \ulcornerUnju Tunnel\ulcorner in Korea were carried out to evaluate the influence of fracture flow, excavation sequence and reinforcement on the tunnel stability. The results of the present study indicate that fracture flow and improper selection of excavation sequence could have a destabilizing effect on the tunnel stability. On the other hand, reinforcement by rockbolts and shotcrete can stabilize the tunnel. It is found that, in general, the D D A program with the three new extensions can now be used as a practical tool in the design of underground structures. In particular, phases of construction (excavation, reinforcement) can now be simulated more realistically.
The Variation of Compressional Wave Velocity with Degree of Saturation in Granites
Lee, Su-Gon ;
Journal of the Korean Geotechnical Society, volume 15, issue 3, 1999, Pages 177~197
The measurement of sonic velocities is commonly used as an index of engineering properties of rock, but it is not widely appreciated that this velocity can change markedly with the degree of saturation of the sample. This paper records the nature of this variation as seen in samples of Korean granite. The ISRM method of testing suggested for this index can also create difficulties, especially if vaseline is used as a coupling agent, and invades the samples, and if the sample volume changes with degree of saturation. Careful measurements of the natural variation in sonic velocity that occur in a sample whose saturation is gradually increased may be a means of assessing the relic stresses within it.