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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 21, Issue 10 - Dec 2005
Volume 21, Issue 9 - Nov 2005
Volume 21, Issue 8 - Oct 2005
Volume 21, Issue 7 - Sep 2005
Volume 21, Issue 6 - Aug 2005
Volume 21, Issue 5 - Jul 2005
Volume 21, Issue 4 - Jun 2005
Volume 21, Issue 3 - Apr 2005
Volume 21, Issue 2 - Mar 2005
Volume 21, Issue 1 - Feb 2005
Selecting the target year
Ratio of Hammer Energy and Dynamic Efficiency of Standard Penetration Test
Lee, Chang-Ho ; Lee, Woo-Jin ;
Journal of the Korean Geotechnical Society, volume 21, issue 9, 2005, Pages 5~12
SPT hammer energy and its delivery are hon to influence the N value. The SPT hammer energy is classified into theoretical energy, velocity energy, rod energy and dynamic efficiency. In this study, the rod energy and the velocity energy are measured directly by PDA and Digital Line-Scan Camera which are most widely used type of SPT apparatus in Korea. The Dynamic efficiency is calculated through measured data. As the results of this study, the averages of rod energy ratio of donut, safety and automatic hammer are measured at 49.57, 61.60, and at
by FV method. The averages of hammer velocity of donut, safety and automatic hammer are measured at
, and at
m/s by Digital Line-Scan Camera, with the dynamic efficiencies at 0.732, 0.801, and 0.973 respectively.
Estimation on Discharge Capacity of Prefabricated Vortical Drains Considering Influence Factors
Shin Eun-Chul ; Park Jeong-Jun ; Kim Jong-In ;
Journal of the Korean Geotechnical Society, volume 21, issue 9, 2005, Pages 13~23
The prefabricated vertical drains (PVDs) are one of the most widely used techniques to accelerate the consolidation of soft clay deposits and dredged soil. Discharge capacity is one of the factors affecting the behavior of PVDs. In the field, a PVD is confined by clay or dredged soil, which is normally remolded during PVD installation. Under field conditions, soil particles may enter the PVD drainage channels, and the consolidation settlement of the improved subsoil may cause 131ding of the PVD. These factors will affect the discharge capacity of the PVDs. In this study an experimental study was carried out to estimate the discharge capacity of three different types of PVDs by utilizing the large-scale laboratory model testing and small-scale laboratory model testing equipments. The several factors such as confinement condition (confined by soft marine clay or dredged soil) and variations of the discharge capacity were studied with time under soil specimen confinement, The test results indicated that discharge capacity decreases with increasing load, time, and hydraulic gradient. With load application, the cross-sectional area of the drainage channel of PVD decreases because the filter of PVD is pressed into the core. The discharge capacity of the soft marine clay-confined PVDs is much lower than that of the dredged soil-confined PVDs.
Evaluation of Geotechnical Parameters Based on the Design of Optimal Neural Network Structure
Park Hyun-Il ; Hwang Dae-Jin ; Kweon Gi-Chul ; Lee Seung-Rae ;
Journal of the Korean Geotechnical Society, volume 21, issue 9, 2005, Pages 25~34
This paper proposes a selection methodology composed of neural network (NN) and genetic algorithm (GA) to design optimal NN structure. We combine the characteristics of GA and NN to reduce the computational complexity of artificial intelligence applications and increase the precision of NN' prediction in the design of NN structure. Genetic selection approach of design parameters of NN is introduced to obtain optimal NN structure. Analyzed results for geotechnical problems are given to evaluate the performance of the proposed hybrid methodology.
Development of the Environmentally Friendly Filling Material for the Underground Cavities using the Rock-dust and an Assessment on Filling and Material Characteristics
Ma Sang-Joon ; Kim Dong-Min ;
Journal of the Korean Geotechnical Society, volume 21, issue 9, 2005, Pages 35~44
Recently, underground cavities such as limestone cavity and abandoned mine give rise to a lot of damage in SOC facilities. But there are many difficult problems such as delay of the working terms and enormous economic losses in finding a new method and changing construction design. In this study, a new filling material for underground cavities was developed using the stone-dust classified as industry waste polluting environment. As a result of test, filling material properties was that a compressive strength was
, a change ratio in length was
and water absorption was
. Also as a result of suspended mass test and pH test, it was confirmed that the developed filling material has a characteristic of non-separating in water and it was an environmentally friendly material.
A Study on the Interaction of Segmented Hydraulic Fractures
Sim Young-Jong ; Kim Hong-Taek ;
Journal of the Korean Geotechnical Society, volume 21, issue 9, 2005, Pages 45~52
Recent observations based on geological evidence and laboratory tests confirm that complex segmentation of hydraulic fractures is common phenomena. It is expected that the segmentation causes mechanical interaction between the fractures and affects fracture opening and measured net pressure. In this study, therefore, the opening of the fractures is computed using boundary collocation method to evaluate the mechanical interaction quantitatively. Also, improved boundary collocation method is suggested to evaluate the displacement of the fracture wall accurately and the reliability of this method is confirmed by comparing with that of the finite element method.
Strength and Stiffness of Silty Sands with Different Overconsolidation Ratios and Water Contents
Kim Hyun-Ju ; Lee Kyoung-Suk ; Lee Jun-Hwan ;
Journal of the Korean Geotechnical Society, volume 21, issue 9, 2005, Pages 53~64
For geotechnical design in practice, soils are, in general, assumed to behave as a linear elastic or perfect plastic material. More realistic geotechnical design, however, should take into account various factors that affect soil behavior in the field, such as non-linearity of stress-strain response, stress history, and water content. In this study, a series of laboratory tests including triaxial and resonant column tests were peformed with sands of various silt contents, relative densities, stress states, OCR and water contents. This aims at investigating effects of various factors that affect strength and stiffness of sands. From the results in this study, it is found that the effect of OCR is significant for the intermediate stress-strain range from the initial to failure, while it may be ignored for the initial stiffness and peak strength. For the effect of water content, it is observed that the initial elastic modulus decreases with increasing water content at lower confining stress and relative density At higher confining stresses, the effect of water content Is found to become small.
Evaluation of Maximum Shear Modulus of Silty Sand in Songdo Area in the West Coast of Korea Using Various Testing Methods
Jung Young-Hoon ; Lee Kang-Won ; Kim Myoung-Mo ; Kwon Hyung-Min ; Chung Choong-Ki ;
Journal of the Korean Geotechnical Society, volume 21, issue 9, 2005, Pages 65~75
Maximum shear modulus of soil is a principal parameter for the design of earth structures under static and dynamic loads. In this study, the statistical data of maximum shear moduli of silty sands in Songdo area in the west coast of Korea evaluated by various field and laboratory tests - standard penetration test (SPT), cone penetration test (CPT), self-boring pressuremeter test (SBPT), downhole test (DH), seismic cone penetration test (SCPT) and resonant column test (RC) were analyzed. Based on the measurement of shear moduli using DH which is known as maximum value at very small strain, the new empirical correlations between shear moduli and SPT or CPT values were proposed. Predictions of maximum shear moduli using the proposed correlations were compared with the data obtained from DH. The good agreement confirmed that the proposed correlations reasonably predicted the maximum shear moduli of silty sands in the area.
Stability Analysis of the Concave Zone in a Slope Considering Rainfall
Sagong Myung ; Lim Kyoung-Jae ;
Journal of the Korean Geotechnical Society, volume 21, issue 9, 2005, Pages 77~86
Since slope sliding and loss of railway triggered by a rainfall produce instability in the operation of trains, a proper method to estimate the slope stability considering rainfall Is required. from the field study, sliding induced by rainfall depends on the engineering properties of soils, three dimensional aspect of the slope, rainfall intensity and geological conditions of the soil layers. In this study, among various types of sliding, slope Instability caused by the surface runoff water at the concave zones in a slope is investigated. The depth of runoff water is calculated by using the Rational method and Manning equation. The occurrence of runoff water is evaluated by a comparison between the calculated infiltration rate and rainfall intensity. Pressure heads which can be calculated from the modified Iverson model are used to calculate the factor of safety along the vertical depth of the slope. The modified Iverson model considers the depth of runoff water, thus the maximum hydraulic gradient along the depth of slope is greater than one.
A Study on the Pile Behaviour Adjacent to Tunnel Using Photo Imaging Process and Numerical Analysis
Lee Yong-Joo ;
Journal of the Korean Geotechnical Society, volume 21, issue 9, 2005, Pages 87~102
In the congested urban areas, tunnelling close to existing structures or services often occurs due to the lack of surface space so that tunnelling-induced ground movements may cause a serious damage to the adjacent structures. This study focused on the two dimensional laboratory model pile-soil-tunnelling interaction tests using a close range photogrammetric technique. Testing equipments and procedures were Introduced, particularly features of aluminium rods regarded as the frictional granular material. The experimental result showed that the photo imaging process by the VMS and EngVis programs proved to be a useful tool in measuring the pile tip movements during the tunnelling. Consequently, the normalised pile tip movement data for the influence zones can be generated by the laboratory model tests using the Photogrammetric technique. This study presents influence zones associated with the normalized pile tip settlements due to tunnelling in the cohesionless material. The influence zones were Identified by both a laboratory model test and a numerical analysis. The normalized pile tip movements from the model test were in good agreement with the numerical analysis result. The influence zones proposed in this study could be used to decide the reasonable location of tunnel construction in the planning stage. However, the scale of model pile and model tunnel sizes must be carefully adjusted as real ones for practical application considering the ground conditions at a given site.