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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Geotechnical Society
Journal Basic Information
Journal DOI :
Korean Geotechical Society
Editor in Chief :
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
Improvement of Consolidation Characteristics around PVD Using the Thermal Method
Bergado, Dennes T. ; Shin, Eun-Chul ; Park, Jeong-Jun ;
Journal of the Korean Geotechnical Society, volume 23, issue 10, 2007, Pages 5~11
This paper is to investigate the removal of the smear at elevated temperatures. This study utilized both small cylinder cell and large consolidometer apparatus to investigate the combination of PVD with heat and without heat. Two types of heaters are used in this study. The heater drain made of copper tube is used for all tests except large consolidometer and flexible wire heater is used for large consolidometer. Specimens demonstrated volume contraction upon heat and without heat. This contraction is dependent on temperature magnitude. When the specimen is heated, the magnitude of settlements is higher and rate of consolidation is faster. After treatment using PVD combined without heat and with heat for undisturbed specimens the
values obtained were
, respectively, from
before treatment. The
ratios were 3 for the specimen without heat and 2 for the specimen with heat. Similarly, in reconstituted specimens without heat and with heat, the
ratios of 1.75 and 1.5, respectively.
Development of Dissipation Model of Excess Pore Pressure in Liquefied Sand Ground
Kim, Sung-Ryul ; Hwang, Jae-Ik ; Ko, Hon-Yim ; Kim, Myoung-Mo ;
Journal of the Korean Geotechnical Society, volume 23, issue 10, 2007, Pages 13~22
Recently, many researches on the dissipation of excess pore pressure in liquefied sand grounds have been performed to evaluate post-liquefaction behavior of structures. In this research, centrifuge tests were performed to analyze liquefaction behavior of level saturated sand grounds. Based on the test results, the evaluation model of solidified layer thickness was developed to simulate non-linear variation of the thickness with time. The thickness evaluation model was combined with the solidification theory and the consolidation theory in order to simulate dissipation of excess pore pressure. The suggested dissipation model properly estimated the solidified layer thickness and the time history of excess pore pressure.
An Experimental Study for Suggestion of Simple Method of Determining the Maximum Relative Density
Lee, Jong-Jin ; Kim, Myong-Mo ; Lee, Seung-Hyun ; Kim, Byoung-Il ;
Journal of the Korean Geotechnical Society, volume 23, issue 10, 2007, Pages 23~31
Although the relative density is an important factor showing mechanical properties of granular soils, the methods for its estimation have not been satisfactorily standardized. Many researchers have proposed various methods to determine max, and min, dry density, but the results, especially for max, dry density, show significant differences. In this study, a simple and practical method of evaluating the max, relative density was proposed, which could give reliable results in comparison with conventional methods. The experiment was carried out by varying the number of blows and the layers of the sample for each mold and the results were compared with those of Bowles method.
Stability Assessment of Concrete Lining and Rock Bolts of the Adjacent Tunnel by Blast-Induced Vibration
Jeon, Sang-Soo ; Kim, Doo-Seop ; Jang, Yang-Won ;
Journal of the Korean Geotechnical Society, volume 23, issue 10, 2007, Pages 33~45
In this study, the blast-induced vibration effects on the structural stability of the adjacent tunnel were estimated with respect to the allowable peak particle velocity (PPV). The blasting distance from the tunnel satisfying the allowable PPV was estimated based on the analytical solutions, United States Bureau of Mines (USBM) suggestions, and the equations used in the subway in Seoul. The allowable blasting distance was estimated by using finite difference analysis (FDA) and the behavior of the concrete lining and rock bolts was examined and the stability of those was estimated during the blast. Research results show that the blast-induced vibration effects on the structural stability are negligible for the concrete lining but relatively large for the rock bolts.
Liquefaction Resistance of Gravel-Sand Mixtures
Kim, Bang-Sig ; Kang, Byung-Hee ; Yoon, Yeo-Won ;
Journal of the Korean Geotechnical Society, volume 23, issue 10, 2007, Pages 47~56
In this research, the effects of the gravel content on the liquefaction behavior for both of the isotropically and
consolidated gravel-sand mixtures are investigated. for this purpose, the cyclic triaxial tests for the specimens with the same relative density (Dr=40%) and variations of gravel content were performed. On the other hand, a series of undrained cyclic triaxial tests were carried out on the isotropically consolidated gravel-sand mixtures with the same void ratio (e=0.7) and from 0% to 30% gravel contents. Void ratios of gravel-sand mixtures with the same relative density (Dr=40%) are found to decrease significantly with the increase of the gravel content from 0% to about 70% and increase thereafter. But the void ratio of the sand matrix among the gravel skeleton increases with the increase of the gravel contents. Test results are as follows : for the isotropically consolidated specimen with 40% of relative density and low gavel contents (GC=0%, 20%, 40%), pore water pressure development and axial strain behavior during undrained cyclic loading show similar behavior to those of the loose sand because of high void ratio, and the specimens with high gravel content (70%) both pore pressure and strata behaviors are similar to those of dense sand. And the isotropically consolidated specimens with the same void ratio (e=0.7) and higher gravel contents show the same behavior of pore water pressure and axial strain as that of the loose sand, but for the lower gravel content this behavior shows similar behavior to that of dense sand. The liquefaction strength of the isotropically consolidated specimens with the same relative density increases with gravel content up to 70%, and the strength decreases with the increase of the gravel content at the same void ratio. Thus, it is confirmed that the liquefaction strength of the gravel-sand mixtures depends both on relative density and void ratio of the whole mixture rather than the relative density of the sand matrix filled among gravels. On the other hand, the behavior of pore water pressure and axial strain for the
consolidated gravel-sand mixtures shows almost the same cyclic behavior of the sand with no stress reversal even with some stress reversal of the cyclic loading. Namely, even the stress reversal of about 10% of cyclic stress amplitude, the permanent strain with small cyclic strain increases rapidly with the number of cycles, and the initial liquefaction does not occur always with less than maximum pore water pressure ratio of 1.0. The liquefaction resistance increases with the gravel contents between 0% and 40%, but tends to decrease beyond 40% of gravel content. In conclusion, the cyclic behavior of gravel-sand mixtures depends on factors such as gravel content, void ratio, relative density and consolidation condition.
The Shear Characteristics of Unsaturated Sandy Soils
Lim, Seong-Yoon ;
Journal of the Korean Geotechnical Society, volume 23, issue 10, 2007, Pages 57~64
Since matric suction of unsaturated soil was related to soil and ground water contaminations, it is very important to analyze its mechanism that was represented by shear characteristics. In three phases of soil, a little air makes the condition of unsaturated soil on contract or shrinkage surface between water and air. Capillarity and suction in pore of unsaturated soil cause surface tension and surface force so it makes negative pore water pressure and increases effective stress as a result. Therefore, negative pore water pressure in partially saturated soil affects the soil structure and degree of saturation and it is important to evaluate accurately unsaturate flow and behavior. In this study, the shear strength characteristics of the seven sandy soils were investigated using consolidated drained triaxial tests with special emphasis on the effects of the negative pore pressure and the matric suction. These tests involved shearing under either a constant net confining pressure and varying matric suction or under a constant matric suction and varying net normal stress.
Friction Behavior at the Soil/Geosynthetic Interface in Respect of Efficiency
Ahn, Hyun-Ho ; Shim, Seong-Hyeon ; Shim, Jai-Beom ; Lee, Seok-Won ;
Journal of the Korean Geotechnical Society, volume 23, issue 10, 2007, Pages 65~72
Large-scale direct shear tests were conducted in order to investigate both the shear strength of soil itself and the friction behavior at the interface of soil/geosynthetics in respect of efficiency in this study. Sand, crushed stone and three types of geotextile (i.e. one woven geotextile and two nonwoven geotextiles) were used in the experimental program. The considered interfaces for the evaluation of interface shear strength in this study included sand/sand, crushed stone/crushed stone, sand/woven geotextile, crushed stone/woven geotextile, crushed stone/nonwoven geotextile-A and crushed stone/nonwoven geotextile-B. The results showed that the efficiency of 84% was obtained at the interface of sand/woven geotextile compared with the shear strength of sand itself (i.e. sand/sand interface). The efficiencies of 74%, 83% and 72% were obtained at the interface of crushed stone/nonwoven geotextile-A, crushed stone/nonwoven geotextile-B and crushed stone/woven geotextile, respectively compared with the shear strength of crushed stone itself (i.e. crushed stone/crushed stone interface).
Mechanism of Dilatory Dissipation during Piezocone Tests in Lightly Overconsolidated Cohesive Soil
Ha, Tae-Gyun ; Jung, Jong-Hong ; Kim, Hong-Jong ; Park, Lae-Seon ; Chung, Choong-Ki ;
Journal of the Korean Geotechnical Society, volume 23, issue 10, 2007, Pages 73~84
For standard piezocones with shoulder filter elements immediately behind the cone tip, general dissipation curves show monotonically decreasing pore pressure from the initial value. However, dilatory dissipation behavior, showing a temporary increase in pore pressure followed by a decrease in the hydrostatic pressure, has been observed in lightly overconsolidated cohesive soils $(1
, which is related to overconsolidation ratio (OCR) and hydrostatic pressure
, affects the dilatory dissipation.
Numerical Analysis of the Nail Behavior Considering Resisting Bending Moment
Jeon, Sang-Soo ; Kim, Doo-Seop ; Jang, Yang-Won ;
Journal of the Korean Geotechnical Society, volume 23, issue 10, 2007, Pages 85~96
The application of soil nailing method has increased because it provides easier construction, economic efficiency, and stability than existing support methods. The mechanical comprehension of the soil-nailing system has not been established and the resisting shear force and bending moment of the soil-nail have been disregarded for the design of soil-nailing system. The soil nail consists of cement associated with rebar and resists shear force and bending moment mobilized by applied loading or soil-self weight. In this study, the slope analysis in the consideration of the resisting shear force and bending moment of the nail has been performed using
, which is programed by the finite difference method.
Estimation Method of Key Block Size on a Large Scale Rock Slope by Simulation of 3-D Rock Joint System
Kim, Dong-Hee ; Jung, Hyuk-Il ; Kim, Seok-Ki ; Lee, Woo-Jin ; Ryu, Dong-Woo ;
Journal of the Korean Geotechnical Society, volume 23, issue 10, 2007, Pages 97~107
Accurate evaluation of the slope stability by assuming failure block as the entire slope is considered to be apposite for the small scale slope, whereas it is not the case for the large scale slope. Hence, appropriate estimation of a failure block size is required since the safety factor and the joint strength parameters are the function of the failure block size. In this paper, the size of failure block was investigated by generating 3-dimensional rock joint system based on statistical data of joints obtained from research slope, such as joint orientation, spacing and 3-dimensional joint intensity. The result indicates that 33 potential failure blocks exist in research slope, as large as 1.4 meters at least and 38.7 meters at most, and average block height is 15.2 meters. In addition, the data obtained from 3 dimensional joint system were directly applicable to the probability analysis and 2 and 3 dimensional discontinuity analysis.
Centrifuge Test for Simulating Behavior of CFRD During Initial Impoundment
Seo, Min-Woo ; Kim, Yong-Seong ;
Journal of the Korean Geotechnical Society, volume 23, issue 10, 2007, Pages 109~119
As the number of CFRD constructions increases, the necessity of an accurate assessment on its behavior also has been increasing. The performance of concrete faced rockfill dam (CFRD) under different water levels is a great concern of dam engineers and designers in the world. However, domestic research on CFRD design and construction has not been performed sufficiently. This study deals with three centrifuge model tests, mainly investigates quantitatively the deformation of the concrete faced slabs and settlements on the crest with different face slab stiffness. The prototype of a centrifugal model dam is half size of domestic CFRD dam. Detailed material preparation, model design, model set-up, model instrumentation and testing procedures are presented. In order to simulate the prototype concrete faced slab, three kinds of thin fiberglass plates with different thickness were adopted in three model tests. Finally, the centrifuge test results were compared with field measurements of domestic dams, which showed that the centrifuge tests were performed successfully.
Model Tests for the Damage Assessment of Adjacent Buildings in Urban Excavation
Kim, Hak-Moon ; Hwang, Eui-Suk ;
Journal of the Korean Geotechnical Society, volume 23, issue 10, 2007, Pages 121~131
This study is to investigate the damage assessment of adjacent structures due to excavation in urban environment. Model tests were carried out for 2 story masonry building and frame structures in various shapes and locations. The damage level of adjacent structures were very differently estimated in accordance with the shape ratio (L/h) of structures, construction stages, and various locations. Therefore the most weak part (bay) of structure must be heavily instrumented and monitored in more details at early stage of constructions. The progressive crack development mechanism at various construction stages was revealed through model tests and crack size indicated more conservative side of damage level on the damage level graph.
Finite Element Modeling of Geogrid-Encased Stone Column in Soft Ground
Yoo, Chung-Sik ; Song, Ah-Ran ; Kim, Sun-Bin ; Lee, Dae-Young ;
Journal of the Korean Geotechnical Society, volume 23, issue 10, 2007, Pages 133~150
This paper presents the results of a research performed to investigate the finite element modeling approach for GESC (Geogrid-Encased Stone Column) method in soft ground within the framework of stress-pore pressure coupled analysis. GESC reinforcement mechanism and construction method was first examined and model verification of stone column on the results of FE analysis was identified. The results indicate that the 3D FE analysis and membrane elements play the most important role in the soft groung using GESC. Based on the results, a modeling method was suggested for stress-pore pressure coupled finite element modelling of GESC in soft ground.
Long-term Behavior Characteristics of Backfilled Ground by EPS
Chun, Byung-Sik ; Jung, Chang-Hee ; Choi, Hui-Rim ;
Journal of the Korean Geotechnical Society, volume 23, issue 10, 2007, Pages 151~161
EPS provides a superb self-sufficient stability. Studies on the process of EPS construction method focus on the inchoate phase of general construction, which is increasingly applied to construction sites throughout the world. Unfortunately, there has been little study on the durability and long-term soil behavior involving EPS materials. In this study, the boring, in-site and laboratory tests were conducted to examine the long-term soil behavior in the back-filling of alternating behind the side to which EPS was applied. And results of finite element analysis considering various test results and the soil behavior data measured during the construction show that EPS construction method is a superb process that relieves the load and consequently reduces the settlement, alleviates the stress on the abutment, and prevents lateral flow.
Behavior of Tunnel Due to Adjacent Ground Excavation with Pre-loading on Braced Wall
Kim, Il ; Lee, Sang-Duk ;
Journal of the Korean Geotechnical Society, volume 23, issue 10, 2007, Pages 163~174
A New pre-loading system, through which a large pre-load could be charged was developed and applied to the braced wall in order to stabilize the adjacent tunnel. A pre-load larger than the designated axial force of bracing was imposed to prevent the horizontal displacement of the braced wall during the ground excavation. For this purpose, real scale model tests (1/10) were conducted, without and with pre-load on braced wall. And numerical analyses were performed for both the cases without and with pre-load, which were half (50%) and full (100%) respectively, and larger scale of the design axial farce of bracing. FEM program called PLAXIS was used for numerical analysis. As a result, it was found that the stability of the existing tunnel adjacent to the braced wall could be greatly enhanced when the horizontal displacement of braced wall was reduced by applying a pre-load, which was larger than the designated axial force of bracing.