역학적 모형에 의한 지오그리드의 장기성능 평가

전한용,정영인,Jeon, Han-Yong,Chung, Youn-In 한국섬유공학회 2006 한국섬유공학회지 Vol.43 No.4

Long-term performance of geogrid should be dependent on the mechanical behaviors during the service periods. Mechanical properties of geogrids are mainly influenced by not only creep deformation behaviors at the constant confining load and temperature but also stress relaxation behaviors at the constant strain and temperature as viscoelastic deformation. In this study, new concept mechanical model was suggested and applied to analyze the long-term performance of geogrid with instantaneous and asymptotic responses. Experimental results of creep and stress relaxation tests of geogrids were compared each other to verify this suggested mechanical model.

Short-Term Compressive Properties and Transmissivity of Geonets

전한용,Jeon, Han-Yong The Korean Fiber Society 2014 한국섬유공학회지 Vol.51 No.2

The relationship between the manufacturing parameters and the compressive behaviors of a traditional bi-planar geonet, the effect of various test conditions on the compression test results for bi- and tri-planar geonets, and the correlation between the normal pressure and the transmissivity of bi- and tri-planar geonets were investigated. The geonet strand inclination can mainly affect the after-compressive strength, i.e., roll-over behavior. For both bi- and tri-planar geonets, the compressive strength decreased and the strain at the yield point increased gradually with temperature. A significant reduction in flow capacity was observed for the traditional bi-planar geonet, and this value was consistent with the compressive strength. These decreases were anticipated owing to the abrupt thickness decrease in the geonet caused by roll-over. On the other hand, no significant decrease was observed in the transmissivity for the tri-planar geonet, which did not roll over.

Performance Assessment of PVA Geotextile/HDPE Geomembrane Composites

전한용,홍상진,류원석,Jeon, Han-Yong,Hong, Sang-Jin,Lyoo, Won-Seok Korean Geosynthetics Society 2005 한국지반신소재학회 논문집 Vol.4 No.1

폐기물 매립지 관련 특성을 조사하기 위하여 PVA 지오텍스타일/HDPE 지오멤브레인 복합재료를 제조하였다. PVA 지오텍스타일의 인장특성, 인열 및 파열강도, 유효구멍크기와 투수성 등을 각각 측정하였다. 또한 침출수에 대한 화학저항성과 자외선 안정성도 측정하였으며, 하중조건에 따른 크리프 변형거동과 마찰특성도 측정하였다. 이들 결과로부터 PVA 지오텍스타일/HDPE 지오멤브레인 복합재료는 일반적으로 폐기물 매립지에 적용되는 폴리프로필렌이나 폴리에스테르 지오텍스타일에 비해 우수한 특성을 나타내었다. 끝으로, 감소인자 분석으로부터 PVA 지오텍스타일/HDPE 지오멤브레인 복합재료의 크리프 변형거동도 폴리프로필렌이나 폴리에스테르 지오텍스타일에 비해 안정함을 알 수 있었다. PVA geotextile/HDPE geomembrane composites were made to examine the waste landfill related properties. Tensile properties, tear and bursting strengths, AOS(apparent opening size) and permittivity of PVA geotextiles were evaluated, respectively. Ultraviolet stability and chemical resistance to the leachate was evaluated also. Friction property and creep deformation were tested at various loading condition. From this, it was seen that PVA geotextile/HDPE geomembrane composites have more excellent properties than the typically used polypropylene and polyester geotextiles in waste landfill. Finally, creep deformation behaviours of PVA geotextile/HDPE geomembrane composites were more stable than polypropylene and polyester geotextiles through the reduction factor analysis.

구성방정식에 의한 폴리에스테르 필름의 응력완화거동 해석 -이온용액중에서의 응력완화거동-

전한용,최영엽,임승순,Jeon, Han-Yong,Choe, Yeong-Yeop,Im, Seung-Sun 한국섬유공학회 1988 한국섬유공학회지 Vol.25 No.5

To analyze the stress relaxation behaviors of PET film in ionic solutions, 5-element mechanical model and its constitutive equations were proposed. And the constitutive equations having two different relaxation mechanisms were used to examine the validity of constitutive equations in 5-element mechanical model. As the radii of ions were decreased, the relaxation stresses were increased. But the relaxation stresses were increased with the increase of draw ratio, ionic strength and ionic value. Besides the relaxation stress, the parameters of constitutive equations in relaxation process were investigated.

Evaluation of Drainage Capacity of Cylindrical Drain Board by Clogging

전한용,이광열,김현중,안병욱,Jeon, Han-Yong,Lee, Kwang-Yeol,Kim, Hyun-Joong,An, Byoung-Wook The Korean Fiber Society 2008 한국섬유공학회지 Vol.45 No.6

Two different core shapes of cylindrical drain are used to evaluate the drainage capacity with consideration of clogging effects on their filter jackets for an applied confining pressure. Column tests with radial drainage system were conducted under confining pressure of 50 kPa for 13 days. Two parameters which are discharge and accumulated volume of water drained were measured as the time elapsing. At the initial stage before the clogging developed enough, the cylindrical drain with angular-type-plastic-core could produce discharge twice higher (maximum) than those with round-type. After 13 days had passed on, cylindrical drain with angular-type-plastic-core could produce discharge only 20% higher than those with round-type one.

부직포를 이용한 건설용 다층 복합재료의 제조 및 물성

전한용,박태영,Jeon, Han-Yong,Park, Tae-Young 한국섬유공학회 1997 한국섬유공학회지 Vol.34 No.2

The polypropylene spunbonded nonwovens and mats were used to manufacture mufftilayered (2 and 3 layered) nonwoven composites for construction. The thermal interlayer norphologies were examined with SEM. The mechanical properties such as tensile, bursting and tear properties were estimated to measure the reinforcement function as the geosynthetic materials. Also, the vertical water flow and permitivity values of these composites were measured. The stress relaxation and creep behaviors within the elastic regions of stress-strain curves indicative of the durability of the geosynthetic materials for the long service periods were analyzed as a function of manufacturing conditions. From these results, it is concluded that the multi-layered composites have the optimum properties as construction materials. In particular, 3-layered composltes composed of spunbonded nonwovens and white mat have shown the increasing tendency of geosynthetic related properties.

Effect of Filter Design Pattern on Engineering Performance of Geotextile Fabric Form

전한용,Jeon, Han-Yong The Korean Fiber Society 2014 한국섬유공학회지 Vol.51 No.5

The hydraulic performance of a geotextile fabric form is strongly dependent on the filter point specifications, such as size, pattern, and repeat units. Furthermore, the stability and long-term performance of a geotextile fabric form are very important when the form is filled with mortar concrete. This paper discusses which filter points influence the long-term performance of a fabric form and the relationship between these specifications and serviceability during installation periods. In addition, engineering properties to be considered in real-world applications were evaluated, such as tensile strength and compressive strength considering shear rupture.

변형거동을 고려한 지오스트립 보강재의 장기성능 평가

전한용,정연인,Jeon, Han-Yong,Chung, Youn-In 한국섬유공학회 2006 한국섬유공학회지 Vol.43 No.4

Strain compatibility was applied to examine the limit of long-term allowable strength determination for geostrip as geosynthetic reinforcement. Creep test was performed for geostrip reinforcements according to SIM(step isothermal method) to obtain isochronous curve. Through the isochronous curve of geostrip reinforcements, the long-term allowable tensile properties of geostrip reinforcements was interpreted and analyzed.

채움재의 입자크기를 고려한 표면결합에 의한 지오멤브레인의 안정성 평가

전한용,정연인,Jeon Han-Yong,Chung Youn-In 한국섬유공학회 2006 한국섬유공학회지 Vol.43 No.3

To confirm the effects of surface defects on the stability of high density polyethylene geomembranes in waste landfill construction conditions, mechanical properties, chemical resistance and failure times of geomembranes under different temperatures were examined. The number of surface defects was increased with the smaller size of scratch induced particles, and the more scratch addition numbers at the shear rate of scratch induced mechanism, 100 mm/min. The tensile strength was decreased but the tensile strain was increased with the above conditions. In chemical resistance of defective geomembranes, the tensile strength was decreased but the tensile strain was increased with the longer immersion period and the higher temperature under the same scratch induced conditions. Finally, failure times of defective geomembranes by 'Notched Constant Tensile Load Test' were shifted to the shorter time ranges by increasing temperatures.

보강토 옹벽 공사용 지오그리드의 제조 및 물성(I) -역학적 및 인발 특성-

전한용,김정효,김홍택,이은수,김영윤,이형규,Jeon, Han Yong,Kim, Jeong Hyo,Kim, Hong Taik,Lee, Eun Soo,Kim, Young Yoon,Lee, Hyung Kyu 한국섬유공학회 1998 한국섬유공학회지 Vol.35 No.10

Geogrid for reinforcement soil retaining wall was constructed with a raw grid woven from 1,000 denier polyester yarns. Low density polyethylene (LDPE) resin dissolved in ethylbenzene was coated to improve the junction strength between warp and weft of raw grid. The weight increase on coating the raw geogrid was about 30~60%. Tensile, junction strength and pullout resistance of geogrids in installation within soil were estimated to verify the reinforcement properties. Tensile strength per unit rib of LDPE coated geogrid was about 30% higher than that of raw grid. For each geogrid, pullout force increased with higher vertical stress, and Grid-M (PVC coated geogrid) had the highest pullout force at constant vertical stress. The induced displacements decreased with higher vertical stress, and Grid-E (LDPE coated geogrid) has the lowest difference range of induced displacement at constant vertical stress.