• Journal of the Korean Geosynthetics Society
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• v.11 no.1
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• pp.65-75
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• 2012

Since the modem reinforced soil wall technology was introduced in domestic civil engineering society in the year 1980, the reinforced soil walls have been extensively used because these technologies have advantages such as economical efficiency, graceful appearance, and easy construction. This paper describes the application of reinforced soil wall, design criteria, and construction problems. Many cases of troubles, which include a severe deformation of facing, cracks of facing block, overall sliding failure and so on, have been reported. Inappropriate design and construction management mainly induce these problems. The technological level of design and quantity control for reinforced soil wall is not sufficiently supported to cope with the growth quantity of reinforced soil wall construction market and the increasing number of construction companies. The unified standard design and construction criteria of reinforced soil wall should be established with the detail consideration of overall performance and stability. The quality control of design and construction, and cost of construction must be seriously executed to construct a high quality of reinforced soil wall.

• Journal of the Korean Geosynthetics Society
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• v.15 no.4
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• pp.105-115
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• 2016

This paper describes a restoration of retaining wall, which was collapsed by rainfall. The failure causes was analyzed by field case, and then the countermeasure was suggested. The failure causes confirmed that observance of design and construction criteria was insufficient. It also was the climate condition like a rainfall and inappropriate construction management. The stability analysis for retaining wall, soil improvement and reinforced earth wall was conducted to confirm validity of the countermeasure. The analysis results showed that the suggested construction method satisfied in required safety factors. Therefore, it should be secured the stability of the structure based on the application of appropriate design method and construction management, when structure was constructed.

• Journal of the Korean Geosynthetics Society
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• v.15 no.4
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• pp.33-42
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• 2016

Discrete Element Method was conducted for rock and coarse-grained materials in development of granular mechanics and related numerical model due to analyze and apply micromechanical property. And it was verified that the analysis to consider bonding effect was insufficient. In this study, to overcome limits of existing method, it was conducted to analyze difference between indoor test result and bonding effect using $PFC^{3D)}$. For indoor test of mixed soil, uniaxial compression tests by curing time and by cement content were performed. And, DEM to suitable for each condition of indoor test was conducted. In the result of this study, in terms of geotechnics, it was verified that DEM can be used for application as numerical laboratory as well as prediction of micro and macro behavior about bonding effect of mixed soil.

• Journal of the Korean Geosynthetics Society
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• v.4 no.1
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• pp.3-6
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• 2005

The failure of geogrids can be defined as an excessive creep strain which causes the collapse of slopes and embankments. In this study, the lifetime of knitted polyester geogrids was predicted by using SIM(Stepped Isothermal Methods using TTS principal) and statistical data analysis techniques. The results indicate that the creep strain was 8.74, 8.79, 8.80% with 2.16~2.20% of CV% at 75, 100, 114 years, respectively and the creep strain reaches 9.3% after 100 years of usage at $27^{\circ}C$ which meets the required lifetime(creep strain less than 10% after 100 years of usage) in the fields. The SIM method is shown to be effective in reduction of uncertainty associated with inherent variability of multi-specimen tests and shorter test times than conventional TTS(Time-Temperature Superposition).

• Journal of the Korean Geosynthetics Society
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• v.2 no.2
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• pp.25-31
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• 2003

Most recently, environmental problems arise from management waste tires by increasing number of automobiles. Waste tires are not compressible and not easy for degradation in landfill. Even if it were landfill, it is difficult to treat. Total amount of waste tires is about 20 million per year and the collection is 68.6% in this country. Structure of slope stability using waste tire blocks filled with concrete increases durability, reduce construction period, and it can be utilized as an example. Therefore, it reduces the volume of waste and recycles waste. Also, it prevents the air pollution due to the incineration and creates economic value.

• Journal of the Korean Geosynthetics Society
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• v.8 no.1
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• pp.53-59
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• 2009

A new system of modified freeze-thaw testing apparatus is introduced. This system is developed to evaluate the geotechnical parameters and their dependence upon freezing-thawing history of frost-susceptibility soil. A necessary condition for stationary frost heaving is clarified in this paper. The method changes the thermal boundary condition up to the net heat flow at the freezing frost becomes zero. The effectiveness of this method is verified by freeze-thaw tests. Frost heaving observed after the application of the method is found to be due to another frost heaving action called long-term frost heaving. This frost heaving has already been studied and is considered ignorable as engineering factor because of its small heaving amount.

• Journal of the Korean Geosynthetics Society
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• v.10 no.1
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• pp.9-18
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• 2011

This paper described that the failure causes of reinforced slope are analyzed based on the effect of geological and rainfall. The analysis result confirmed that the rainfall has effects on the stability of reinforced slope. Therefore, it was applied to the dewatering method using collector well for slope stabilized, and then the analysis of seepage and slope stability were conducted on slope with the applied method. The results of seepage analysis are corresponded with failure cause by rainfall and the results of slope stability, which is applied to dewatering method, are satisfied with safety factor criterion. Therefore, it confirmed that the dewatering method using collector could be possible to apply in field and reasonable method for slope stabilized during heavy rainfall.

• Journal of the Korean Geosynthetics Society
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• v.13 no.2
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• pp.21-29
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• 2014

The use of filling material based on cement paste is inefficient at field construction because it needs a lot of the charging mass. In addition, it has environmental problem according to the large amount of cement use because its strength is also larger than criterion. The excavated soil with stabilizer can be used as the filling materials when the bored pile is constructed. Therefore, this paper describes field application of solidified soil for economical efficiency and environment-friendly. The static axial load tests and the load-transfer measurements were performed to examine the axial resistant behavior of the piles. As results, the flowability, segregation and bleeding, and bond strength of filling materials was a good performance than that of the existing cement paste. But the skin friction of pile by PDA was slightly decreased than that of the existing cement paste. However, as pile filling materials, and in terms of economics and environment, the applicability of filling material is considered very effective.

• Journal of the Korean Geosynthetics Society
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• v.5 no.2
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• pp.45-50
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• 2006

Although the discharge capacity of the natural fiber drains are very low compared to that of plastic drain board (PDB), it is found that the conventional fiber drains and the new developed straw drain boards have great potential for use as a substitute for conventional plastic drain boards through several model tests. To verify their field application, a pilot test using environmentally friendly drains is also being carried out to prove their effective discharge capacity in the field. The pilot test site was divided into 5 different areas, with various combinations of vertical and horizontal drains installed for evaluation. Definite characteristics of various drains are still to be found due to the delay in construction of embankment. Consolidation behavior of three types of vertical drains and two types of horizontal drains will be analyzed after the completion of the embankment in the near future.

• Journal of the Korean Geosynthetics Society
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• v.13 no.4
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• pp.161-167
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• 2014

This paper describes reinforcement method of reinforced earth wall near the abutment. The excessive displacement of a case affected by reduction of bearing capacity due to macro-environment condition like a coast. That is, the front displacement of reinforced earth wall has been happening continuously due to strength reduction of foundation ground. The micro pile is applied to reinforcement method, in order to secure a bearing capacity and global slope stability of reinforced earth wall. The results of numerical analysis confirmed that reinforcement method based on micro pile can secure a stability of structure, while the reconstruction of reinforced earth wall is impossible by construction and macro-environment condition.