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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Geoenvironmental Society
Journal Basic Information
Journal DOI :
Korean Geo-Environmental Society
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Volume & Issues
Volume 13, Issue 12 - Dec 2012
Volume 13, Issue 11 - Nov 2012
Volume 13, Issue 10 - Oct 2012
Volume 13, Issue 9 - Sep 2012
Volume 13, Issue 8 - Aug 2012
Volume 13, Issue 7 - Jul 2012
Volume 13, Issue 6 - Jun 2012
Volume 13, Issue 5 - May 2012
Volume 13, Issue 4 - Apr 2012
Volume 13, Issue 3 - Mar 2012
Volume 13, Issue 2 - Feb 2012
Volume 13, Issue 1 - Jan 2012
Selecting the target year
A Study on the Applicability of Prediction Methods for Long-term Ground Settlement in Soft Ground of Gyeongnam Area
Park, Eunhyung ; An, Ducklae ; Chae, Hwiyoung ; Chun, Byungsik ;
Journal of the Korean Geoenvironmental Society , volume 13, issue 10, 2012, Pages 5~13
In this study, the degrees of consolidation were evaluated by analyzing the long-term settlement measured at the 3 work sites with soft ground in Gyeongnam Area. The Hyperbolic, Hoshino and Asaoka method were used, which were focused on prediction of long-term settlement of land on the basis of field measurement data. And the applicability of the settlement prediction method according to the measurement periods was investigated by analyzing the degree of consolidation at the target areas after dividing the terms into early and latter parts. According to the results obtained at the early stage of consolidation, the Hyperbolic method appeared to be in the highest applicability level, which was followed by Asaoka and Hoshino method in the order of level. In the case of latter stage of consolidation, Asaoka method appeared to be in the highest applicability level, which was followed by and the Hyperbolic, Hoshino method in the order of level.
Estimating Groundwater Level Variation due to the Construction of a Large Borrow Site using MODFLOW Numerical Modeling
Ryu, Sanghun ; Park, Joonhyeong ; Kim, Gyoobum ;
Journal of the Korean Geoenvironmental Society , volume 13, issue 10, 2012, Pages 15~23
A numerical model and field monitoring data are used to estimate a change in groundwater level at a borrow site, which will be constructed at the mountainous area with a large ground excavation in the study area, Hwaseong city. Lithologic data and hydraulic coefficients are collected at 9 boreholes and also groundwater levels are measured at these boreholes and existing wells in the study area. Additionally, groundwater recharge rate for the type of land cover is estimated using water budget analysis; 133.34mm/year for a mountainous area, 157.68mm/year for a farming area, 71.08mm/year for an urbanized area, and 26.06mm/year for a bedrock exposure area. The change in groundwater level in and around a borrow site is simulated with Modflow using these data. The result of a transient model indicates that a removal of high ground (over 40El.m) by an excavation will produce a decrease in groundwater levels, up to 1 m, around a borrow site in 10 years. It also explains that this ground excavation will bring about the decreases of 9.4% and 7.0% for groundwater recharge and surface runoff, respectively, which are the factors causing groundwater level's change. This study shows that it is required to construct the groundwater monitoring wells to observe the change of groundwater near a borrow site.
Variation of Electrical Resistivity Characteristics in Sand-Silt Mixtures due to Temperature Change
Park, Jung-Hee ; Seo, Sun-Young ; Hong, Seung-Seo ; Kim, YoungSeok ; Lee, Jong-Sub ;
Journal of the Korean Geoenvironmental Society , volume 13, issue 10, 2012, Pages 25~32
The application of electrical resistivity, which is related to charge mobility, has increased in the field of geotechnical engineering for the detection of underground cavern, faults and subsurface pollution level. The purpose of this study is to investigate the variation of electrical resistivity due to temperature change. Sand-silt mixture specimens prepared in the square freezing nylon cell are frozen in the frozen chamber. Four electrodes are attached on the four side walls of the freezing cell for the measurement of electrical resistance during temperature change. Electrical resistances of sand-silt mixtures with different degrees of saturation (0%, 2.5%, 5%, 10%, 20%, 40%, 60% and 100%) are measured as the temperature of specimens decrease from
. The electrical resistances determined by Ohm's law are transformed into the electrical resistivity by calibration. Experimental results show that the higher degree of saturation, the lower electrical resistivity at
. Electrical resistivity gradually increases as the temperature decrease from
. For the specimens with the degree of saturation of 15% or higer, electrical resistivity dramatically changes near the temperature of
. In addition, very high electrical resistivity is observed regardless of the degree of saturation if the specimens are frozen. This study provides the fundamental information of electrical resistivity according to the soil freezing and temperature change demonstrates that electrical resistivity be a practical method for frozen soil investigation.
Analyses of Widely Used Design Codes for Pile Foundation Using the t-z Method
Park, Sungwon ; Misra, Anil ;
Journal of the Korean Geoenvironmental Society , volume 13, issue 10, 2012, Pages 33~42
The efficiency of the current design methods for computing pile resistances is analyzed using field load-settlement tests results. Twelve load-settlement test data for drilled shafts and bored piles were obtained from the literature. These load-test data were fitted using the t-z method. Subsequently, the ultimate resistances were evaluated based upon the failure criteria from following methods: (1) the Davisson's approach and (2) settlement corresponding to 5% or 10% shaft diameter approach. The ultimate resistances for these drilled shafts and bored piles were also predicted using methods based on the design code from North America (United States, Canada), Europe, and Asia (Japan). The pile resistances determined from field load-settlement tests were compared with those calculated using the design codes. The comparisons show that most design codes predict a conservative resistance for drilled shafts and bored piles. However, in the case of drilled shafts, we find that some of the design codes can over-predict the resistance and, therefore, should be applied cautiously. This research also shows that the t-z method can be successfully used to predict the ultimate resistance and the load transfer mechanism for a single pile.
Experimental Study for Consolidation by Electric Heating Systems
Park, Min-Cheol ; Im, Eun-Sang ; Lee, Kum-Sung ; Han, Heui-Soo ;
Journal of the Korean Geoenvironmental Society , volume 13, issue 10, 2012, Pages 43~53
This study deals with the conventional consolidation methods like preloading and vertical drains. For it, Two different mechanism, i.e., increasing of permeability and evaporating of pore water were studied. The marine clays excavated in Incheon were heated at low temperature(
) to increase the permeability. Also, Microwave oven and high-temperature electric heater were used for pore water evaporation. Several points raised from the experiments. To fix them, the electric heating system was revised to upgrade the field application and drain efficiency of pore water, and the marine clays were heated by revised electric heater at high temperature(
). From Experimental result showed that results, high-temperature heater induced the pore water evaporation and displayed the excellent consolidation behavior. In addition, the cone index of heated clays were increased about 19 times, which suggested that electric heating system could be applied for ensuring the trafficability of heavy equipments.
Numerical Modeling of Large Triaxial Compression Test with Rockfill Material Considering 3D Grain Size Distribution
Noh, Tae Kil ; Jeon, Je Sung ; Lee, Song ;
Journal of the Korean Geoenvironmental Society , volume 13, issue 10, 2012, Pages 55~62
In this research, the algorithm for simulating specific grain size distribution(GSD) with large diameter granular material was developed using the distinct element analysis program
(Particle Flow Code). This modeling approach can generate the initial distinct elements without clump logic or cluster logic and prevent distinct element from escaping through the confining walls during the process. Finally the proposed distinct element model is used to simulate large triaxial compression test of the rockfill material and we compared the simulation output with lab test results. Simulation results of Assembly showed very well agreement with the GSD of the test sample and numerical modeling of granular material would be possible for various stress conditions using this application through the calibration.
Correlation Conditions for Marine Microalgae Isochrysis galbana under Illumination of Light Emitting Diodes
Choi, Boram ; Kim, Dongsoo ; Lee, Taeyoon ;
Journal of the Korean Geoenvironmental Society , volume 13, issue 10, 2012, Pages 63~68
This study was performed to determine optimum conditions of batch type cultivation of Isochrysis galbana cultivated under various wavelengths of light emitting dioes (LEDs). Among LEDs used in the cultivation, white LED was found to be the most effective light source, and light intensity of 3,000Lux resulted in the most effective for the cultivation of Isochyrysis galbana. Comparison with common light source, fluorescent light, showed less effective than that with white LED. Four different air flow rates were tested to overcome shading effects due to denser cell concentration in the solution. In results, cell growth rates and maximum cell concentrations were similar regardless of air flow rates. Three times greater cell concentrations, however, were observed when air was applied.
The Effects of Hydroxyl Radical Generation by Means of the Addition of
in the Electron-beam Process
Kwon, Bumgun ; Kwon, Joongkuen ; Kim, Jongoh ;
Journal of the Korean Geoenvironmental Society , volume 13, issue 10, 2012, Pages 69~76
This study focuses both on the quantitative measurement of hydroxyl radicals formed by an electron beam (E-beam) process and on the decomposition of pentachlorophenol(PCP) in the presence of
as additives. To attain this objective, the quantitative measurement of hydroxyl radical was performed with the hydroylation of benzoic acid (BA), producing hydroxybenzoic acid (OHBA). As a result, the concentrations of hydroxyl radical measured were lower than those of hydroxyl radical predicted. Probably, it indicates that the reactive species generated during E-beam irradiation are able to scavenge the hydroxyl radicals. In particular, the degradation of PCP was promoted by the addition of
(< 1mM). On the other hand, its degradation as well as the generation of chloride ions as a by-product was inhibited by the addition of
(> 1mM), and thus carbon yield(%) of oxalic acid as a by-product was increased. During E-beam irradiation the addition of
effectively decomposed the PCP, thus increasing the G-values. Considering the formation of OHBA and the decomposition of PCP, these results suggest that the addition of
in the E-beam process can produce the further hydroxyl radicals and enhance the efficiency of PCP decomposition at low dose.
A Study on the Ground Improvement Effect with Grouting in Backside of Retaining Wall
Chu, Ickchan ; Byun, Yoseph ; Baek, Seungin ; Chun, Byungsik ;
Journal of the Korean Geoenvironmental Society , volume 13, issue 10, 2012, Pages 77~83
Recently, excavations using propped walls were popularized in downtown due to reduced settlement of nearby structures. These excavations is induced strain to propped walls or settlement in near ground. In this study, the ground reinforcing effect was proven using NDS, which is an inorganic injection material. Injection tests were performed to compute optimum injection pressure and volume. Next, calibration chamber tests were performed by using computed injection pressure and volume, and wall behaviour was examined for overburden pressures of 50kPa and 150kPa. Ground reinforcing effect was shown when the material behind the propped wall was grouted. From test results, optimum injection pressure was 350kPa and the optimum volume was 10L considering economics. Calibration chamber test results show that after the material was grouted, the maximum settlement was reduced to 19% of the non-grouted condition. For overburden pressures of 50kPa and 150kPa behind the wall, the settlement of the wall increased by 58% and 57% when compared to the case of no overburden pressure.
A Case Study on the Cause and Reinforcement of Railroad Facilities Settlement According to the Ground Excavation
Oh, Beyung-Sam ;
Journal of the Korean Geoenvironmental Society , volume 13, issue 10, 2012, Pages 85~94
Recent development trend of construction projects in the urban area is the efficient use of insufficient land, however caused to difficult construction conditions because of many adjacent structures. This paper presents the case study that analyzed the ground settlement of railroad structure for the double track railway project of Gyeongui line, adjacent to the high rise building under ground excavating for substructure work, considering interaction of soft ground characteristics. Field survey and measurement works were carried out during construction of station and excavation of high rise building, and field data were analyzed to find the source of settlement of platform and railway. In addition, the soil reinforcement and foundation restoration were performed using in-situ injection method, i.e., D-ROG(Digitalized Restoring On Grout) method which filled the pore of bottom and around of foundation with micro-cement.