• Journal of the Korean Geosynthetics Society
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• v.5 no.3
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• pp.31-36
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• 2006

In this study, stress relaxation behaviors of nonwoven geotextile and geomembrane which have protection, filtration and drainage, water barrier functions, respectively were examined. 'Theory of transition phenomen' was applied to interpretate the stress relaxation behaviors of two geosynthetics. The initial and later relaxation times for stress relaxation behaviors of geosynthetics were derived from the constitutive equations. The initial relaxation behaviors of these geosynthetics were dependent on the additional strains and were especially faster with temperature. Finally, both relaxation times of geosynthetics were shorter with additional strain and temperature and the reduction of relaxation times of nonwoven geotextile were larger than those of geomembrane.

• Journal of the Korean GEO-environmental Society
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• v.9 no.5
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• pp.53-59
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• 2008

The purpose of the study was to evaluate how much gastropod shell effected its properties better than crushed stone as coarse grained materials by comparing friction properties of a contact surface between coarse grained materials and geosynthetics with the large-scale direct shear test. To achieve the purpose, the study compared and analyzed friction coefficient and friction angle by making crushed stone or gastropod shell into model ground and by installing and shearing non-woven fabric or geostrip geosynthetics. As the results of the analysis, crushed stone had the internal friction angle of $33.8^{\circ}$ when its unit weight was $13.7kN/m^3$ and gastropod shell had the internal friction angle of $35.4^{\circ}$ when its unit weight was $5.4kN/m^3$. Also, the friction angle of a contact surface between geosynthetics and crushed stone was larger than the friction angle of a contact surface between geosynthetics and gastropod shell.

• Journal of the Korean Geotechnical Society
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• v.19 no.5
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• pp.263-272
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• 2003

Various types of geosynthetics have been manufactured and their applications are rapidly extended disregarding unreliable lifetime, chemical and biological persistence and puncture resistance. Puncture resistance of geosynthetics in earth structures and liner systems has been a critical issue to be improved. In this paper, comparative studies were made on a puncture resistance of various geosynthetics that were used to a liner system. Two types of puncture tools and rubles and gravels were used to generate punctures on geosynthetics. From the results it is shown that types of puncture tools affect puncture resistance of materials significantly and puncture forces were irregular depending upon puncture tools and materials.

• Geotechnical Engineering
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• v.24 no.2
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• pp.17-23
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• 2008

• Water for future
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• v.44 no.6
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• pp.37-41
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• 2011

미국 캘리포니아 주 어바인 시에 위치한 피터스 캐년 샛강(Peters Canyon Creek) 수중에 과포함되어 있는 셀레늄(Dissolved Selenium)과 질산성 질소(Nitrate-N)를 제거하려는 목적으로 바이오 필터 셀 시스템을 시범 시공하였다. 바이오 필터셀 시스템은 3m(높이) ${\times}$ 65m(길이) ${\times}$ 14m(폭) 크기를 가진 상자형태의 셀을 기준으로 취수 및 전처리 시스템과 후처리 시스템으로 구성되었으며, 셀은 여러 종류의 지오신세틱스와 거친 표면을 가지고 있는 자갈을 이용하여 건설되었다. 특히, 지오신세틱스가 가지고 있는 장점인 유연성(flexibility)과 화학적 안정성으로 인한 무반응성(non reactive material)등은 성공적인 시스템 구축에 큰 영향을 주었다.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.293-302
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• 2010

2 types of geogrids and geotextiles was used to evaluate shear behaviors after installation damage test. Shear behaviors were compared after installation damage test and coefficient of resistance to direct sliding($f_{ds}$) was estimated by theoretical shear analysis. Shear strength of damaged geogrid decreased under high normal stress of 150kPa and shear strength of geotextile decreased with increasing normal stress. It is seen that $f_{ds}$ values after installation damage decreased than before installation damage through comparison calculated $f_{ds}$ by direct theoretical shear analysis. $f_{ds}$ values to be calculated by theoretical shear analysis were changed with before and after installation damage.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.64-68
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• 2003

The purpose of the study is to compare the efficiency of protection as a liner protective material for geosynthetics. A series of tests were conducted in this study to analyze the effects of geosynthetics against puncture loads. Various types of geosynthetics are used as a protective material. Non-woven, Geo-composite, NaBento GCL, GCL are used to create puncture failure that caused by vertically applied loads. The results indicated that combination of geosynthetics and a protective material can be subjected to bigger loads than geosynthetics and a protective material separated each other do.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.196-203
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• 2008

Durability of geosynthetics for soil reinforcement is accounted for creep and creep rupture, installation damage and weathering, chemical and biological degradation. Among these, the long-term creep properties have been considered as the most important factors which are directly related to the failure of geosynthetic-reinforced soil(GRS). However, the creep test methods and strain limits are too various to compare the test results with each other. The most widely used test methods are conventional creep test, time-temperature superposition and stepped isothermal method as accelerated creep tests. Recently developed design guidelines recommend that creep-rupture curve be used to determine the creep reduction factor($RF_{CR}$) which is a conservative approach. In this study, the different creep test methods were compared and the creep reduction factors were estimated at different creep strain limits of 10% of total creep strain and creep rupture. In order to minimize the impact of creep strain to the GRS structures, the various creep reduction factors using different creep test methods should be investigated and then the most appropriated one should be selected for incorporating into the design.