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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 25, Issue 12 - Dec 2009
Volume 25, Issue 11 - Nov 2009
Volume 25, Issue 10 - Oct 2009
Volume 25, Issue 9 - Sep 2009
Volume 25, Issue 8 - Aug 2009
Volume 25, Issue 7 - Jul 2009
Volume 25, Issue 6 - Jun 2009
Volume 25, Issue 5 - May 2009
Volume 25, Issue 4 - Apr 2009
Volume 25, Issue 2 - Feb 2009
Volume 25, Issue 1 - Jan 2009
Selecting the target year
Calibration of Borehole Roughness Measurement System for Large Diameter Drilled Shafts in Water
Park, Bong-Geun ; Nam, Moon-S. ; Choi, Yong-Kyu ;
Journal of the Korean Geotechnical Society, volume 25, issue 8, 2009, Pages 5~21
Based on recent studies on rock socketed drilled shafts, it was found that the side resistance of rock socketed drilled shafts is affected by unconfined compressive strength of rock, socket roughness, rock types and joints, and initial normal stress. Especially, the socket roughness is affected by rock types and joints, drilling methods, and diameters. Since existing roughness measurement systems could be conducted only in the air, a new roughness measurement system, which can measure rock socket roughness in the air and also in the water, is needed. However, the development of new roughness measurement system fur civil engineers has been faced with difficulties of electrical applications. In this study, the laboratory verification system far BKS-LRPS (Backyoung-KyungSung Laser Roughness Profiling System) was developed, which can be applied both in the water and air. Based on the laboratory verification, it was found that the improved BKS-LRPS could define effective measurement distances for the conditions reflecting the apparatus and in-situ situations.
Development of New Settlement Model for Prediction of Settlement Characteristics of SCP Composite Ground
You, Sang-Ho ; Park, Hyun-Il ; Im, Jong-Chul ; Park, Lee-Keun ;
Journal of the Korean Geotechnical Society, volume 25, issue 8, 2009, Pages 23~32
In this study, the reliable and simple analysis method was proposed to predict the settlement characteristic of composite ground in stage of design and construction of sand compaction pile (SCP). Model parameters could be obtained by the optimization process based on genetic algorithm. In order to examine the proposed method, laboratory consolidation tests on the settlement characteristic of SCP composite ground were performed for various replacement ratio of sand such as 0 (no replacement), 20, 36, and 56%. The proposed model showed very good agreements with measured data in the relation of void ratio-log scaled stress and time-compression far each replacement ratio.
Comparison on the Performance of Soil Improvement in Thick Soft Ground Using Single-Core and Double-Core PBD
Yang, Jeong-Hun ; Hong, Sung-Jin ; Kim, Hyung-Sub ; Lee, Woo-Jin ; Choi, Hang-Seok ;
Journal of the Korean Geotechnical Society, volume 25, issue 8, 2009, Pages 33~45
The conventional single-core PBDs have been widely used in order to accelerate consolidation settlement of soft grounds. When using the single-core PBD in a thick clay deposit, a delay of consolidation may occur due to high confining pressure in the thick deposit and necking of drains. This study is to compare the performances of soil improvement by the single-core and double-core PBD installed at a site in Busan New Port which exhibits approximately a 40m-thick clay layer. An in-situ test program was performed at the test site where a set of the double-core PBDs and single-core PBDs were installed to compare the efficiency of each drain. In addition, the discharge capacity of each PBD has been measured using the modified Delft Test. A series of laboratory tests for estimating in-situ soil properties have also been performed in order to obtain input parameters for a numerical program ILLICON. The discharge capacity of the double-core PBD is higher than that of the single-core PBD in the modified Delft Test. However it is observed from the comparative in-situ test and numerical analysis that there is no difference in the performance of ground improvement between the two drain systems. This discrepancy comes from the fact that the amount of water released during consolidation in most common field conditions is much smaller than the capacity of even the single core PBD. And thus, considering actual field conditions, it can be concluded that the single-core PBD has enough discharge capacity even in the thick clay deposit such as this test site.
Characteristics of Shell-Residual Soil Mixture Deformation by Cyclic Loading
Chang, Yong-Chai ; Seo, Ji-Woong ; Lee, Seung-Eun ;
Journal of the Korean Geotechnical Society, volume 25, issue 8, 2009, Pages 47~55
This research has the purpose to examine the potential of shell, a byproduct of maritime products to be utilized as alternative environment-friendly construction material by mixing and applying it with residual soit which is used as burial or filling material to recycle it. To that end, the research looked into the mechanical characteristics of shell through cyclic triaxial test by mixing it with residual soil. With the mixing ratios of shell of 5 groups set at 5.0%, 10.0%, 20.0%, 40.0% and 60.0%, the mixture soils was processed through a series of cyclic triaxial tests. And it was shown that liquefation resistance has limitation in the mixed soils with shell substitute content ratios exceeding 20.0%. To increase the liquefaction resistance of the mixed soil, this research has shown that addition of moderate amount of glass fibers would suffice.
Estimation of Axial toad Capacity for Tapered Piles Using Equivalent Transformation
Jun, Sung-Nam ; Seo, Kyung-Bum ; Song, Won-Jun ; Lee, Jun-Hwan ;
Journal of the Korean Geotechnical Society, volume 25, issue 8, 2009, Pages 57~64
In this study, a method using equivalent transformation for estimation of the axial load capacity of tapered piles is proposed. While preexistent methods for estimating the axial load capacity of tapered piles have been based on the effect of soil state and taper angle, a new design method is proposed considering cone resistance
and equivalent transformation in sand. Through tapered pile simplified by using equivalent transformation, a new method fur quick and easy estimation of the axial load capacity of tapered pile is proposed for practical use. In order to verify the proposed method, calibration chamber test and field test were conducted. In calibration chamber test, comparison of estimated axial load capacity with measured one showed that the standard deviation and COV (Coefficient Of Variation) of estimated
respectively. For field test, axial load capacity by proposed method shows 2.5% under-estimation in comparison with measured value. As a result, it is found that proposed method produces satisfactory predictions for tapered piles.
Estimation of Uniaxial Compressive Strength and Elastic Modulus from Brazilian Test
Min, Tuk-Ki ; Moon, Jong-Kyu ; Ro, Jai-Sool ;
Journal of the Korean Geotechnical Society, volume 25, issue 8, 2009, Pages 65~76
Little attention has been paid to Brazilian test for the estimation of uniaxial compressive strength and elastic modulus of rocks as an indirect method despite high availability of civil engineering parameters. This paper employed Brazilian test value to estimate two parameters of igneous rocks (granite, andesite, rhyolite) of Korea. High reliability of Brazilian test has been supported by the conclusions drawn from point load test and Schmidt hammer strike values. It has also been found that this method can be applied easily and rapidly to the estimation of uniaxial compressive strength and elastic modulus of rock cores when direct tests are not available.
End Bearing Load Transfer Behavior of Rock Socketed Drilled Shafts
Cho, Hoo-Yeon ; Jung, Sang-Sum ; Seol, Hoon-Il ;
Journal of the Korean Geotechnical Society, volume 25, issue 8, 2009, Pages 77~93
The load distribution and deformation of rock socketed drilled shafts subjected to axial loads were evaluated by a load transfer approach. The emphasis was laid on quantifying the end bearing load transfer characteristics of rock socketed drilled shafts based on 3D Finite Difference (FD) analysis performed under varying rock strength and rock mass conditions. From the results of FD analysis, it was found that the ultimate unit toe resistance (
) was influenced by both rock strength and rock mass conditions, while the initial tangent of end bearing load transfer curve (
) was only dependent on rock strength. End bearing load transfer function of drilled shafts socketed in rock was proposed based on the FD analysis and the field loading tests which were performed on weathered rock in South Korea. Through the comparison with the results of the field loading tests, it is found that the load transfer curve by the present study is in good agreement with the general trend observed by field loading tests, and thus represents a significant improvement in the prediction of load transfer behavior of drilled shaft.
Long-term Compression Settlement of Granular (Rock/Soil Mixture) Fill Materials under Concrete Track
Lee, Sung-Jin ; Lee, Il-Wha ; Lee, Jin-Wook ; Lee, Jun-S. ;
Journal of the Korean Geotechnical Society, volume 25, issue 8, 2009, Pages 95~106
This study was intended to identify the effect of the wetting on a long-term compression settlement of the rock/soil mixture used as fill material, depending on compaction and grading conditions. The relatively large settlement happened under the fully-submerged condition, and a repeated settlement was monitored when moisture content increased over and over again like the rainfall infiltration. In case of the materials without fine fractions or compacted in wet condition, the settlement caused by wetting was relatively low. In conclusion, the long-term compression settlement of granular (rock/soil mixture) fill material is more affected by the increase of water content and temperature change (freezing and thawing) than creep.