• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.03a
• /
• pp.866-873
• /
• 2009

CFRD (Concrete Faced Rockfill Dam) has been world-widely constructed due to a lot of advantages compared with rockfill dam and recently, sand/gravel materials, instead of crushed rock materials, are also utilized as a main rockfill material to overcome geological and environmental problems. In this paper, the process of water infiltration into the originally unsaturated sand/gravel-fill dam is studied using two-dimensional saturated-unsaturated seepage theory. According to the results of seepage analysis, if the effective drainage zone is installed in the dam, the reservoir water infiltrate into the dam along a downward flow path towards the lower drainage area. The main body constructed with sand/gravel materials, therefore, remains unsaturated.

• Journal of the Korean GEO-environmental Society
• /
• v.13 no.5
• /
• pp.13-24
• /
• 2012

In this study, the in-situ model test has been conducted and used to estimate and analyze consolidation behavior of the ground by using the miniature test that reconstructs economically geotechnical behavior of in-situ full scale structure. To analogize the relation among effective stress, void ratio and coefficient of permeability at the self-weight consolidation stage, the low stress seepage consolidation test has been conducted and the involution function of constitutive equation had been obtained from the result of the curve fitted seepage consolidation test result. As a result of the numerical analysis that had been conducted on the representative section using a constitute equation, final settlement was similar with those of self-weight consolidation of the centrifugal model test. But, it was more or less smaller. It seems that these trends are caused by the difference between estimated values.

• Journal of the Korean Geotechnical Society
• /
• v.37 no.10
• /
• pp.41-54
• /
• 2021

In this study, probabilistic steady seepage behavior of soil foundation beneath water retaining structures according to the location of cutoffs was studied. A Monte Carlo Simulation based on the random finite element method that considers the uncertainty and spatial variability of soil permeability was performed to evaluate the probabilistic seepage behavior. Fragility curves were developed by calculating the failure probability conditional on the occurrence of a given water level from the probability distribution obtained from Monte Carlo simulations. The fragility curve was prepared for the flow quantities such as flow rate through foundation soil, uplift force on the base of structure, and exit gradient in downstream to examine the reliability of the water retaining structure and the foundation soil. From the fragility curves, the effect of the location of cutoff wall on the reliability of water retaining structure and foundation soil according to the rise in water level was studied.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.58 no.3
• /
• pp.81-90
• /
• 2016

It is significant to redevelop the deterioration reservoir through raising for countermeasure to climate change and Earthquake improvement of reservoir. This study aims to investigate the behavior of deterioration reservoir with poor-fabricated core subjected to raising water level and earthquake using numerical analysis. From the analysis results, water level raising and earthquakes induce crack and subsidences at the crown and the front side of deterioration reservoir. For the reinforcement of the deterioration reservoir is required appropriate measures method and raised method suitable, drainage and slope protection method judged to be necessary.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.7 no.3
• /
• pp.209-218
• /
• 2005

In a NATM tunnel, fully grouted bolts are widely used as part of supporting system. Grouted bolts play an important role not as to take some parts of load acting on the tunnel lining but as to reinforce the ground adjacent the tunnel. In conjunction with tunnel construction, the presence of groundwater may pose a number of difficulties. With respect to tunnel design, influences of groundwater on tunnel behavior have been considered in many aspects. However, the effect on grouted bolts has been rarely investigated. In this study, the behavior of grouted bolts, which are affected by the seepage forces, was examined. In order to investigate the effects of seepage forces, the theoretical solutions for a drained condition were proposed. Based on the theoretical solutions, ground reaction curves considering seepage forces were obtained. By comparing the ground reaction curves supported by grouted bolts with those for the unsupported cases, the effect of reinforcement was evaluated. Finally, through comparison between supported ground react ion curve s in the drained condition and those in the case of groundwater flow, it was observed that the grout ed bolts are more structurely beneficial when the seepage occurs towards the tunnel than when there is no groundwater flow.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.56 no.1
• /
• pp.71-79
• /
• 2014

In this study, an experiment with large-scale model was performed according to raising the embankment in order to investigate the behavior of failure for embankment and spillway transitional zone due to overtopping. The pore water pressure, earth pressure, settlement and failure pattern by a rapid drawdown and overtopping were compared and analyzed. The pore water pressure and earth pressure at spillway transitional zone by overtopping increased a rapidly with the expansion of seepage erosion, but the crest showed a smally change due to effect of the inclined core type. And it is considered an useful data that can accurately estimate the possibility of failure of the reservoirs. A settlement at overtopping decreased a rapidly due to failure of crest. The relative settlement difference due to change of the water level at the upstream and downstream slope cause increase largely crack of crest. The behavior of failure by overtopping was gradually enlarged towards reservoirs crest from the bottom of the spillway transition zone, the inclined core after the raising the embankment was influenced significantly to prevent the seepage erosion.

• Journal of the Korean GEO-environmental Society
• /
• v.5 no.3
• /
• pp.41-50
• /
• 2004

The study of seepage behavior is very important to slope stability of road landfill for heavy rainfall season. This study is done to propose more stable of road landfill based on analysis of seepage behavior and slope stability for some cases of road landfill. The selected sections of collapsed road landfill are most general case of road landfill, a case is landfill on the ground area and another case is on the slope area. The results of this study is summarized as follows. It is founded that the road landfill on the ground area is increased saturation region due to rainfall infiltration, and the seepage behavior of road landfill is solved by theory of unsaturated flow. The road landfill is more unstable due to rainfall infiltration at the slope surface, especially during heavy rainfall. The case of road landfill on the slope area is analyzed in consideration of slope surface infiltration, and it is founded that the slope instability is increased because of rainfall infiltration. The drain layer located on the original ground which made by more permeable materials could be good action of slope stability in the case of road landfill on the slope area.

• Journal of Korean Society on Water Environment
• /
• v.29 no.4
• /
• pp.489-496
• /
• 2013

Ground water underlying soil is vulnerable to pollution by organic chemicals through their percolation through the soil system. This study was conducted to provide information on the seepage behavior of organic chemical contaminants in clay, silty and sandy soils. Chloroform, 1,1,1-trichloroethane and trichloroethylene are readily transported through the soil; their percolated mass were 4.6-19.2 percent of the total mass applied. Tetrachloroethylene, 1,2-dichlorobenzene and 1,3-dichlorobenzene were retarded by soils due to sorption. Between 0.6 and 4.8 percent of the material applied to the surface percolated within the experimental period. Carbon tetrachloride was attenuated considerably by passage through soils. Only 0.1-0.4 percent of the mass reached the groundwater. Significant degradation of bromoform was observed. Apparent breakdown of intermediates of the brominated compounds were detected. Transformations of the brominated compounds appear to be the result of both biological and chemical processes. The effect of soil type on the mobility of organic chemical contaminants was considerable. The organic contaminants moved faster in sandy soil than in either clay or silty soils.

• Journal of the Korean Geotechnical Society
• /
• v.27 no.10
• /
• pp.93-104
• /
• 2011

In this paper, a numerical procedure of probabilistic steady seepage analysis that considers the spatial variability of soil permeability is presented. The procedure extends the deterministic analysis based on the finite element method to a probabilistic approach that accounts for the uncertainties and spatial variation of the soil permeability. Two-dimensional random fields are generated based on a Karhunen-Lo$\grave{e}$ve expansion in a fashion consistent with a specified marginal distribution function and an autocorrelation function. A Monte Carlo simulation is then used to determine the statistical response based on the random fields. A series of analyses were performed to verify the application potential of the proposed method and to study the effects of uncertainty due to the spatial heterogeneity on the seepage behavior of soil foundation beneath water retaining structure with a single sheet pile wall. The results showed that the probabilistic framework can be used to efficiently consider the various flow patterns caused by the spatial variability of the soil permeability in seepage assessment for a soil foundation beneath water retaining structures.

• Journal of the Korean Geotechnical Society
• /
• v.30 no.3
• /
• pp.17-28
• /
• 2014

In this study, the seepage behavior has been analyzed, which is the most important in determining the stability of the embankment. Large-scale embankment of weathered granite has been installed and TDR (time domain reflectory) sensors were used to detect the seepage lines. The TDR graphs could be separated into 3 sections, which are initial, unsaturated and saturated zones. TDR sensor can detect seepage line more easily than point sensor without analysis. Comparisons of the results of numerical analyses and the TDR sensors showed differences at water level rising condition, and then Comparisons of the results generally showed good agreement at another condition.