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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Geoenvironmental Society
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Journal DOI :
Korean Geo-Environmental Society
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Volume & Issues
Volume 8, Issue 6 - Dec 2007
Volume 8, Issue 5 - Oct 2007
Volume 8, Issue 4 - Aug 2007
Volume 8, Issue 3 - Jun 2007
Volume 8, Issue 2 - Apr 2007
Volume 8, Issue 1 - Feb 2007
Selecting the target year
An Experimental Study on the MSG Reinforcement of Steel Pipe Pile Installed by PRD
Chun, Byungsik ; Kang, Heejin ; Kong, Jinyoung ;
Journal of the Korean Geoenvironmental Society , volume 8, issue 6, 2007, Pages 5~12
Mudstone has characteristics that it has high enough strength and stiffness in a dry condition, but the strength and stiffness decrease in a wet condition with groundwater infiltration. The sliding of cut slope frequently encountered in Pohang area has been reported due to the rapid reduction of shear strength in mudstone after being exposed to the air. The study in this paper shows that mudstone having enough strength in a boring stage has lost the strength after installing PRD (percussion rotary drill) steel pipe pile inducing an insufficient bearing capacity. Field test has been performed to investigate the most favorable method for increasing a pile bearing capacity in mudstone with various methods such as MSG (Micro Silica Grouting) around the tip and side of a pile, the perimeter grouting combined with Micro pile reinforcement, and concrete filling after tip reinforcing grouting. MSG has been turned out to be the most favorable method for increasing a pile bearing capacity in mudstone, confirmed by the static load test.
The Effects of Sand Compaction by Watering through Field Compaction Test and Numerical Analysis
Chun, Byungsik ; Jang, Younsoo ; Kim, Kwanggyu ; Park, Dukhyum ; Sung, Hwadon ;
Journal of the Korean Geoenvironmental Society , volume 8, issue 6, 2007, Pages 13~19
This study examines a cause for damage of synthetic resins straight pipe occurred after pipe construction of underground electric power duct pipelines of
city railroad. For this, we analyzed a parameter used for plan and structural analysis through a literature review. And the site condition was analyzed in detail, and test construction of the pipe line that simulated the site pipe line and test on compaction by watering were performed. In addition, an examination on subsurface settlement influence of foundation ground through a structural safety and a numerical analysis of power transmission pipe line was performed. As a result of the performance, relative density gained by compaction by watering was more than average and relative degree of compaction according to technical specification standard showed the result of about 90% in the case of good compaction by watering.
Sewage Treatment using Membrane Bioreactor(MBR) and Reverse Osmosis(RO) Process
Oh, Seungwook ; Jung, Jongtae ; Lee, Jinwoo ; Kim, Jongoh ;
Journal of the Korean Geoenvironmental Society , volume 8, issue 6, 2007, Pages 21~28
The objective of this study was to investigate the effect of hydraulic retention time (HRT) on removal efficiencies of organic matter, nitrogen and phosphorus in MBR-RO process for treating synthetic sewage. In MBR process, turbidity was less than average 2 NTU and average removal efficiency showed more than 99% during the operation period(MBR 105 day). As a result of HRT variation, average removal efficiencies of
on HRT 6, 12, 18 and 24hour were about 72.4, 84, 88.6 and 92.5%, respectively. The
removal efficiency was about 60.2 85.5, 91.3 and 92.2%, respectively. T-N and T-P removal efficiencies increased from 53.7 and 56.8 to 82.5 and 86.4%, respectively as the HRT increased from 6 hour to 24 hour. In RO process, average removal efficiencies of color and
in RO permeate were about 99.9% and 96.8%, respectively. Also, removal efficiencies of T-N,
and T-P were all above average 90%.
Deformation Analysis of a Shallow NATM Tunnel using Strain Softening Model and Field Measurement
Lee, Jaeho ; Kim, Youngsu ; Moon, Hongduk ; Kim, Daeman ; Jin, Guangri ;
Journal of the Korean Geoenvironmental Society , volume 8, issue 6, 2007, Pages 29~36
The control and prediction of surface settlement, gradient and ground displacement are the main factors in urban tunnel construction. This paper carried out the estimation and prediction of ground behavior around tunnel due to excavation using computational method and case study in detail for the analysis of deformation behavior in urban NATM tunnel. Computational method was performed by FLAC-2D with strain softening model and elastic plastic model. Field measurements of surface subsidence and ground displacement were adopted to monitor the ground behavior resulting from the tunneling and these values were applied to modify tunnel design parameters on construction.
Layer Interface and Approximated Nonlinear Analysis Method for Consolidation Prediction
Lee, Kyuhwan ; Jeon, Jesung ; Kim, Kiyoung ; Jung, Daeesuk ;
Journal of the Korean Geoenvironmental Society , volume 8, issue 6, 2007, Pages 37~43
The interface layer having different consolidation properties and nonlinear material function with permeability needs to be considered to predict consolidation behavior. In this study, interface equation between different layers has been derived and then applied to existing finite difference scheme for conducting consolidation analysis. These results have been compared with those by conventional method in which different layers are converted to single layer having conversion value of properties. Also, although the conventional consoilidation analysis is used to consider non-linearity of the permeability with effective stress, an approximated nonlinear method as a function of consoilidation coefficient with effective stress have been developed and applied to the consoilidation analysis for various cases.
Estimation of Reinforcement Effect of Superannuated Fill Dam Repaired by the Permeable Grouting Method
Kim, Yungjin ; Heo, Yol ; Oh, Byunghyun ;
Journal of the Korean Geoenvironmental Society , volume 8, issue 6, 2007, Pages 45~52
Maintenance of structural and hydrological safety of the superannuated fill dam is very important subject on the viewpoint of disaster prevention. Mainly, the core of the superannuated fill dams have been damaged continuously by the various harmful external forces such as the typhoons, flash floods and earthquake, and these can be connected to the large scaled general dam failure. Therefore, the research on the repair, remediation and reinforcement of dam is necessary. In this study, the permeable grouting method for the remediation of fill dam was examined by the electrical resistivity survey and the change of permeability of core front. As a result, the permeable grouting method can be useful remediation method for the superannuated fill dam, the leakage from the core front decreased greatly before and after the construction of grouting. Furthermore, it can be said that the turbidity of fill dam may not be greatly increased by grouting.
Application of EPS Considering Long-term Durability
Chun, Byungsik ; Jung, Changhee ; Ahn, Jinhyun ;
Journal of the Korean Geoenvironmental Society , volume 8, issue 6, 2007, Pages 53~60
L/EPS, manufactured in the shape of block and used for civil engineering, is a lightweight material with an excellent resistance to compression, and provides a superb self-sufficient stability. EPS is a suitable material capable of resolving the problem of settlement and lateral flow if it is applied as the soil on soft ground. The Korean Standards (KS) has not yet proposed any testing method for use of EPS as an engineering banking material. Only its testing and quality ordinance as a heat insulation material has been standardized. The design criteria for EPS has been established and applied through the trial construction of KHC (Korea Highway Corporation) and quality test of manufacturer, but most studies on them have been confined to factory products. This study is focused on comparing and analyzing long-term durability by conducting cyclic load test, freezing and thawing test, absorption rate test and others. EPS used in the test was chosen from construction sites and factory products, focusing on the long-term durability of EPS depending on the passage of time. Unconfined compression test results indicated that the strength of collected samples was lower than factory products. While the triaxial compression test results indicated that the shear strength increased in proportion to the increase of confining pressure, and factory products had declining shear strength as the confining pressure rose.
An Evaluation Method of Deformation Moduli using Finite Element Analysis of Cyclic Plate Load Tests
Oh, Seboong ; Seo, Wonseok ; Kwon, Ohkyun ;
Journal of the Korean Geoenvironmental Society , volume 8, issue 6, 2007, Pages 61~68
The problem on cyclic plate load tests was analyzed by finite element method using an anisotropic hardening constitutive model. The constitutive model was coded to user subroutine in ABAQUS. Using the result of the analysis, Young's moduli corresponding to various strain levels were evaluated by a back calculation method and were very similar to those of input. On the basis of the back calculation method plate loading tests were verified. As a result, deformation moduli could be evaluated practically from cyclic plate load tests with respect site conditions.
Liquefaction Strength of Shelly Sand in Cyclic Simple Shear Test
Yoon, Yeowon ; Yoon, Gillim ; Choi, Jaekwon ;
Journal of the Korean Geoenvironmental Society , volume 8, issue 6, 2007, Pages 69~76
The sands which use for soil improvement of soft ground at coastal area contain more or less amount of shells. In this research the effects of shell contents on the liquefaction resistance of the shelly sand were studied. NGI cyclic simple shear tests were performed for the shell-sands with shell contents of 0%, 5%, 10%, 20%, 30% under the effective vertical stress of 50kPa, 100kPa and 150kPa for 40% and 55% of relative density, respectively. Cyclic simple shear test results showed that for the low effective vertical stress, the liquefaction resistance increased rapidly with increase of shell contents in both 40% and 55% relative density. On the other hand, for the high effective vertical stress, the liquefaction resistance increased slightly in 40% relative density and was almost same in 55% relative density. Liquefaction resistance decreased with increasing effective vertical stress for both 40% and 55% relative density. In the same effective vertical stress and shell contents, liquefaction resistance increased with the increase of relative density.
Deformation Behavior of Existing Concrete-Faced Rockfill Dam due to Raising
Shin, Donghoon ; Cho, Sungeun ; Jeon, Jesung ; Lee, Jongwook ;
Journal of the Korean Geoenvironmental Society , volume 8, issue 6, 2007, Pages 77~83
In this study, deformation behavior of existing concrete face rockfill dam, which is raised to a certain height to enhance storage capacity or to improve hydraulic and hydrologic stability, is examined using numerical analysis method. The results obtained from FEM analysis show a possibility that additional fill at downstram slope of existing CFRD dam body may lead undesirable deformations and stresses in existing dam body, especially in face concrete, such as settlements in upper part and bulging in lower part, excessive bending moments, and eventualy tensile cracks. Therefore, in designing multi-staged raising construction of CFRD, it is essential to consider deformations and stresses to be developed within and between exisiting dam body and added parts due to additional fill, and to prepare a proper measure to prevent abnormal deformations and stresses in the dam body including added parts.
Auxiliary Reinforcement Method for Collapse of Tunnel in the Coal Shale Fractured Zone
Kim, Nagyoung ; Moon, Changyeul ; Park, Yongseok ;
Journal of the Korean Geoenvironmental Society , volume 8, issue 6, 2007, Pages 85~95
It is difficult for seismic survey to get hold of characteristic of coal shale fractured zone and if coal shale zone did not come into contact with underground water, coal shale zone has characteristic of good strength. But in case coal shale zone is exposed by excavation or blasting to the air, strength of coal shale zone decreases in short term and weathering of coal shale zone progresses rapidly. Therefore, the prediction of tunnel collapse is not easy in the coal shale zone and the great portion of tunnel collapse takes place in a moment. From a view point of strength, after twelve hours form result of point load test strength of coal shale decreases by fifty six percent when coal shale zone come into contact with ground water. The standard reinforcement design of coal shale fractured zone was presented in the paper.