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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 :
Seong Wan Park
Volume & Issues
Volume 22, Issue 12 - Dec 2006
Volume 22, Issue 11 - Nov 2006
Volume 22, Issue 10 - Oct 2006
Volume 22, Issue 9 - Sep 2006
Volume 22, Issue 8 - Aug 2006
Volume 22, Issue 7 - Jul 2006
Volume 22, Issue 6 - Jun 2006
Volume 22, Issue 5 - May 2006
Volume 22, Issue 4 - Apr 2006
Volume 22, Issue 3 - Mar 2006
Volume 22, Issue 2 - Feb 2006
Volume 22, Issue 1 - Jan 2006
Selecting the target year
Bearing Capacity Characteristic of Dredged and Reclaimed Ground Reinforced by Bamboo Net
Kang, Myoung-Chan ; Yang, Kee-Sok ; Lee, Song ;
Journal of the Korean Geotechnical Society, volume 22, issue 8, 2006, Pages 5~11
A series of large scale plate loading tests are performed to assess bearing capacity characteristic of dredged and reclaimed ground that is reinforced by bamboo net and geotextile as a surface strengthen method. Bearing capacity ratio is distributed from 3.46 to 6.03 for bamboo net and from 2.19 to 3.59 for Geotextile In case of bamboo net, BCR was obtained from 1.6 to 1.7 times than Geotextile. As the comparison of each bearing capacity from test and theory shows, bearing capacity theory for geotextile was not suited for bamboo net. The bearing capacity analysis reinforced by bamboo net shows a good relationship between sand mat thickness (H) / bamboo net space (S), and bearing capacity ratio (BCR).
The Stability of Bridge Abutment Reinforced by Pile-slab on Soft Ground Undergoing Lateral Flow
Hong, Won-Pyo ; Song, Young-Suk ;
Journal of the Korean Geotechnical Society, volume 22, issue 8, 2006, Pages 13~24
A site investigation has been performed for bridge abutments constructed on soft ground, which are deformed laterally by backfill. As the result from the evaluation of lateral movement in bridge abutment, the foundation piles were not considered as the passive pile at the design stage and the period for soft ground improvement was not proper. In order to prevent lateral movement of bridge abutment, the pile slab is proposed as a countermeasure. This method can effectively prevent the lateral flow of soft ground, since the overburden surcharge due to backfill on soft ground would be effectively delivered to bedrock through the piles in soft ground. The instrumentation system is designed and installed to investigate the behavior of bridge abutment on soft ground reinforced by pile slab. The instrumentation results show that pile slab effectively resists to the lateral movement of bridge abutment due to backfill. Also, the surcharge loads due to backfill are transmitted to the bedrock through piles. It confirms that the pile slab effectively resists to the lateral movement of bridge abutment due to backfill and the applied design method is reasonable.
The Influence of Negative Skin Friction on Piles in Groups Connected to a Cap
Lee, Cheol-Ju ; Park, Byung-Soo ;
Journal of the Korean Geotechnical Society, volume 22, issue 8, 2006, Pages 25~31
Over the years the investigation of behaviour of piles in groups connected to a cap in consolidating soil has attracted far less attention than the study of isolated piles in groups. In this paper, a series of three-dimensional numerical simulations have been performed to study the behaviour of pile groups connected to a cap in consolidating ground. Both elastic no-slip and elasto-plastic slip analyses were considered. Based on the analysis results, when piles were connected to a cap, tensile forces were developed near the pile head at the outer piles. Elastic solution and no-slip analysis over-predicted the tensile force near the pile head for outer piles. Relatively speaking, the number of piles in a group is more important than the pile spacing in terms of the influence of negative skin friction on the pile behaviour. The issue on the development of tensile forces on the pile head at the outer piles is perhaps needed to be carefully considered in the pile design to prevent the damages of the pile-cap connection.
Long Term Behaviors of Geosynthetics Reinforced Soil Walls
Won, Myoung-Soo ; Lee, Yong-An ; Kim, You-Seong ;
Journal of the Korean Geotechnical Society, volume 22, issue 8, 2006, Pages 33~42
Geosynthetics reinforced soil (GRS) walls with a flexible wall face allow deformation. GRS walls constructed on the weak ground change in both horizontal earth pressures on wall faces and the tensile stress of geosynthetics, affecting the backfill in time until the deformation of the backfill and the foundation is completed. However, there are few studies that were done to measure and analyze the horizontal earth pressures and geosynthetics deformation on GRS walls constructed on the soft ground for a long period of time. Two field GRS walls in this study are constructed on a shallow layer of a weak foundation to measure and analyze geostynthetics deformation, horizontal earth pressures, and pore water pressures for the duration of approximately 16 months. Strain gauges are used to measure geosynthetics deformation; this study specifically suggests a new method of measuring nonwoven geotextile using strain gauges. Most geosynthetics deformation occurred within a month after the construction of GRS walls. The maximum deformation measured for approximately 16 months appeared as follows: nowoven geotextile: 6.05%, woven geotextile: 2.92%, and geogrid: 2.33%. Pore water pressures on the GRS wall can be ignored; however, horizontal earth pressures on the bottom and the upper part of the wall face appear larger than earth pressures at rest.
Application of Bender Elements in Consolidation, Tomography, and Liquefaction Tests
Lee, Jong-Sub ; Lee, Chang-Ho ;
Journal of the Korean Geotechnical Society, volume 22, issue 8, 2006, Pages 43~54
The scope of this paper covers the applications of bender element tests in consolidation, tomography, and liquefaction. Loading and unloading time during consolidation are evaluated based on shear wave velocity. As S-wave velocity is dependent on effective stress, the loading step may be determined. However, cautions are required due to the different mechanism between the settlement and effective stress criteria. The stress history may be evaluated because the S-wave shows the cement controlled regime and stress controlled regimes. A fixed frame complemented with bender elements permits S-wave tomography The tomography system is tested at low confinement within a true triaxial cell. Results show that shear wave velocity tomography permits monitoring changes in the velocity field which is related to the average effective stress. To monitor the liquefaction phenomenon, S-wave trans-illumination is implemented with a high repetition rate to provide detailed information on the evolution of shear stiffness during liquefaction. The evolution of shear wave propagation velocity and attenuation parallel the time-history of excess pore pressure during liquefaction. Applications discussed in this paper show that bender elements can be a very effective tool for the detection of shear waves in the laboratory.
Behaviour of the Excess Pore Pressure Induced by Sand Mat on the Soft Clay
Kim, Hyeong-Joo ; Lee, Min-Sun ; Paek, Pil-Soon ; Jeon, Hye-Sun ;
Journal of the Korean Geotechnical Society, volume 22, issue 8, 2006, Pages 55~62
The design of sand mat should be reviewed by the behaviour of excess pore pressure which is obtained by combining characteristics of soft ground with the permeability of sand mat. In this paper, in order to investigate the distribution of hydraulic gradient of sand mat, a banking model test was performed using dredged sand as materials of sand mat, and these results were compared by the numerical analysis results utilizing Terzaghi's consolidation equation. The results show that the pore pressure was influenced by the settlement increasing in the central area of sand mat as the height of embankment increases, and uprising speed of excess pore pressure due to residing water pressure is delayed compared with the results of numerical analysis. Finally, the construction of sand mat should be spreaded to reduce the increased hydraulic gradient at the central area of embankment.
A Review of Strength Estimation Method on Ulsan Sedimentary Rocks
Min, Tuk-Ki ; Moon, Jong-Kyu ;
Journal of the Korean Geotechnical Society, volume 22, issue 8, 2006, Pages 63~72
In the ASTM and ISRM, an uniaxial compressive strength(
) has been estimated to be 23(ASTM) or
(ISRM) times of point load strength index using a diametral test regardless of the rock rating or geological conditions. This paper presents a relationship between
of a weak sedimentary rocks on Ulsan of the Kyung-Sang Basin in Korea. In the results of 291 for
test and 2310 for
test from 77 spots, the predicted errors of
determined by strength ratio of
have been relatively less than those determined by linear regression analysis. And in case of weak sedimentary rocks such as mudstones, shales and sandstones,
should be lower than those suggested by ISRM and ASTM.
A Study on the Lateral Behavior of Pile-Bent Structures with
Jeong, Sang-Seom ; Kwak, Dong-Ok ; Ahn, Sang-Yong ; Lee, Joon-Kyu ;
Journal of the Korean Geotechnical Society, volume 22, issue 8, 2006, Pages 77~88
In this study, the lateral behavior of Pile-Bent structures subjected to lateral loading was evaluated by a load-transfer approach. An analytical method based on the Beam-Column model and nonlinear load transfer curve method was proposed to consider material non-linearity (elastic and yielding) and
effect. Special attention was given to the lateral deflection of Pile-Bent structures depending on different soil properties, lateral load, slenderness ratio based on pier length and reinforcing effect of casing. From the results of the parametric study, it is shown that the increase of lateral displacement in a pile is much less favorable for an inelastic analysis than for an elastic analysis. It is found that for inelastic analysis, the maximum bending moment is located within a depth approximately 3.5D(D: pile diameter) below ground surface, but within 1.5D when
effect is considered. It is also found that the magnitude and distribution of the lateral deflections and bending moments on a pile are highly influenced by the inelastic analysis and
effect, let alone soil properties around an embedded pile.
The Thickness of Shear Zone in Granular Materials Using Digital Image Processing
Min, Tuk-Ki ; Kim, Chi-Young ;
Journal of the Korean Geotechnical Society, volume 22, issue 8, 2006, Pages 89~97
This study investigated the effect of relative density on the thickness of shear zone. Digital image processing was used to measure the thickness of shear zone under plane strain conditions. A suitable epoxy resin was injected into the sample and the thickness of the shear zone was investigated. Four independent condition samples were prepared and the thickness of the shear zone was measured. The results indicated that the thickness of shear zone increases as the initial density of sample increases, and during the shear, the void ratios of the shear zone were changed, but the thickness of shear zone was not changed. In addition, the result of measurement of the thickness showed that the thickness of shear zone was almost fixed before critical state, but beyond critical state, the thickness of shear zone sharply increases as relative density increases.
Effect of Hardening of Granulated Blast Furnace Slag on the Liquefaction Strength
Baek, Won-Jin ;
Journal of the Korean Geotechnical Society, volume 22, issue 8, 2006, Pages 99~106
In the present study, in order to clarify the effects of latent hydraulic property of granulated blast furnace slag (GBF slag) on the liquefaction, GBF slag was cured in the high temperature alkali water (adding the calcium hydroxide, pH=12, water temperature is about
), and then the cyclic and the static tri-axial compression tests were carried out. Then the results were compared with those for Japanese standard sand of Toyoura sand and natural sand of Genkai sand. From the test results, it is clarified that the liquefaction strength of the GBF slag increases with the increase of the curing period by the hardening due to the latent hydraulic property. It is also shown that GBF slag with Dr=50% and 80% which was cured for 189 days in the fresh-water shows cohesion due to developing of latent hydraulic property. In addition, as for the liquefaction strength of GBFS during the hardening process, a linear relation between the cyclic stress ratio
at the number of stress cycles Nc=20 and cohesion
was observed. It is also clarified that the liquefaction strength for cured GBF slag in the high temperature alkali water is predicted by the cohesive strength or the unconfined compressive strength.
Tunnel-lining Back Analysis Based on Artificial Neural Network for Characterizing Seepage and Rock Mass Load
Kong, Jung-Sik ; Choi, Joon-Woo ; Park, Hyun-Il ; Nam, Seok-Woo ; Lee, In-Mo ;
Journal of the Korean Geotechnical Society, volume 22, issue 8, 2006, Pages 107~118
Among a variety of influencing components, time-variant seepage and long-term underground motion are important to understand the abnormal behavior of tunnels. Excessiveness of these two components could be the direct cause of severe damage on tunnels, however, it is not easy to quantify the effect of these on the behavior of tunnels. These parameters can be estimated by using inverse methods once the appropriate relationship between inputs and results is clarified. Various inverse methods or parameter estimation techniques such as artificial neural network and least square method can be used depending on the characteristics of given problems. Numerical analyses, experiments, or monitoring results are frequently used to prepare a set of inputs and results to establish the back analysis models. In this study, a back analysis method has been developed to estimate geotechnically hard-to-known parameters such as permeability of tunnel filter, underground water table, long-term rock mass load, size of damaged zone associated with seepage and long-term underground motion. The artificial neural network technique is adopted and the numerical models developed in the first part are used to prepare a set of data for learning process. Tunnel behavior, especially the displacements of the lining, has been exclusively investigated for the back analysis.
A Study on Earth Pressure Properties of Granulated Blast Furnace Slag Used as Back-fill Material
Baek, Won-Jin ; Lee, Kang-Il ;
Journal of the Korean Geotechnical Society, volume 22, issue 8, 2006, Pages 119~127
Granulated Blast Furnace Slag (GBFS) is produced in the manufacture process of pig-iron and shows a similar particle formation to that of natural sea sand and also shows light weight, high shear strength, well permeability, and especially has a latent hydraulic property by which GBFS is solidified with time. Therefore, when GBFS is used as a backfill material of quay or retaining walls, the increase of shear strength induced by the hardening is presumed to reduce the earth pressure and consequently the construction cost of harbor structures decreases. In this study, using the model sand box (50 cm
100 cm), the model wall tests were carried out on GBFS and Toyoura standard sand, in which the resultant earth pressure, a wall friction and the earth pressure distribution at the movable wall surface were measured. In the tests, the relative density was set as Dr=25, 55 and 70% and the wall was rotated at the bottom to the active earth pressure side and followed by the passive side. The maximum horizontal displacement at the top of the wall was set as
. By these model test results, it is clarified that the resultant earth pressure obtained by using GBFS is smaller than that of Toyoura sand, especially in the active-earth pressure.
Characteristics of Engineered Soils
Lee, Jong-Sub ; Lee, Chang-Ho ; Lee, Woo-Jin ; Santamarina, J. Caries ;
Journal of the Korean Geotechnical Society, volume 22, issue 8, 2006, Pages 129~136
Engineered mixtures, which consist of rigid sand particles and soft fine-grained rubber particles, are tested to characterize their small and large-strain responses. Engineered soils are prepared with different volumetric sand fraction, sf, to identify the transition from a rigid to a soft granular skeleton using wave propagation,
, and triaxial testing. Deformation moduli at small, middle and large-strain do not change linearly with the volume fraction of rigid particles; instead, deformation moduli increase dramatically when the sand fraction exceeds a threshold value between sf=0.6 to 0.8 that marks the formation of a percolating network of stiff particles. The friction angle increases with the volume fraction of rigid particles. Conversely, the axial strain at peak strength increases with the content of soft particles, and no apparent peak strength is observed in specimens when sand fraction is less than 60%. The presence of soft particles alters the formation of force chains. While soft particles are not part of high-load carrying chains, they play the important role of preventing the buckling of stiff particle chains.