• Proceedings of the Korean Geotechical Society Conference
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• 2001.06a
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• pp.45-54
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• 2001

In this study, slope stability analysis of LCRS(Leachate Collection Removel System) in waste landfill was peformed by large scale field test. Geocomat is new type of geocomposite product. Gecomat is a sort of Geocomposite product. It is composed of nonwoven geotextiles, woven geotextile, and geonet. Large scale field tests were performed on the slope of different two LCRSsections with static loading condition. One is LCRS section witch consist of GCL, HDPE and Geocomat, another is GCL, HDPE, and woven type geocomposite. The behavior of geosynthetics lined slope was monitored by incorporating instrumentation including vertical soil pressure meter, settlement plate, strain gauges, potential meter, displacement pin.. Based on the field monitoring, the Geocomat LCRS section is less sliding than the conventional geocomposite LCRS section.

• Journal of the Korean Geotechnical Society
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• v.22 no.9
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• pp.61-68
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• 2006

Recently the large scale civil engineering projects are being implemented by reclaiming the sea or utilizing seashore and river embankment areas. The reclaimed land and utilized seashore are mostly soft ground that doesn't have sufficient bearing capacity. This soft ground consists of fine-grained soil such as clayey and silty soils or large void soil like peat or loose sand. It has high ground water table and it may cause the failure and crock of building foundation by uplift pressure and ground water leakage. In this study, the permittivity and the transmissivity were evaluated with the applied normal pressure in the laboratory. The laboratory model tests were conducted by utilizing geocomposite drainage system for draining the water out to release the uplift pressure. The soil used in the laboratory drainage test was dredged soil from the reclaimed land where uplift pressure problems can arise in soil condition. Geocomposite drainage system was installed at the bottom of apparatus and dredged soil was layered with compaction. Subsequently the water pressure was supplied from the top of specimen and the quantities of drainage and the pore water pressure were measured at each step water pressure. The results of laboratory measurements were compared with theoretical values. For the evaluation of propriety of laboratory drainage test, 2-D finite elements analysis that can analyze the distribution and the transferring of pore water pressure was conducted and compared with laboratory test results.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.621-628
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• 2003

To prevent the percolation of leachate through the bottom of waste landfills, the liner system of various layers, such as compacted clay, geomembrane, geonet, geotextiles, and geocomposite is designed. Since the friction angle between a geomembrane and other geosynthetics is usually lower than that of the soil alone, the interfaces between soil and geosynthetic or geosynthetic-geosynthetic may become a possible plane of weakness, which leads to potential instability of the system under load of waste at side slopes. In this study, large triaxial tests are carried out with samples of remoulded wastes and direct shear interface friction tests are carried out to understand the frictional properties of geosynthetic-geosynthetic interfaces, which are required for analyzing the safety of side-slope liner systems.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.241-245
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• 2000

In this paper, the results of the direct shear interface friction test is introduced to understand interface friction between geosynthetic materials that are required for analyzing slope stability of the liner system of waste landfills. Tensile stresses that occur in a liner system due to differential settlement with waste load are estimated using FLAC. It was shown that HDPE/geocomposite inteface friction angle is 11.9$^{\circ}$, HDPE/wastes is 12.0$^{\circ}$ and geotextile/wastes is 28.0$^{\circ}$. Tensile stress due to settlement in a foundation of landfill is well within the limits of tensile strength regulated by waste treatment law.

• Journal of the Korean GEO-environmental Society
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• v.10 no.3
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• pp.21-28
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• 2009

As the natural aggregates such as sand and clay are getting exhausted, the quantity of utilizing geosynthetics is being increased in the solid waste landfill. Especially, the waste landfills have been constructed at the gorge in the mountainous area and reclaimed land from the sea in the Korean Peninsula. Those areas are not favorable for construction of waste landfill in geotechnical engineering aspect. In this study, the frictional characteristics of geosynthetics that used in the waste landfill were estimated. Then, the studies of the behavior of geosynthetics and stability of LDCRS (Leachate Detection, Collection, and Removal System) of side slope were conducted in the waste landfill by means of the pilot test, and numerical analysis. Geocomposite which is combined type or separated type is influenced on the strain itself, and also implicated in the stress and strain of geomembrane at the lower layer. The strain on the combined type of geocomposite is about 50% smaller than that of the separated type at the side slope. The lateral displacement and settlement of top at the slope with the separated type are three times greater than that of the combined type. In the numerical analysis, discontinuous plans in between ground and geosynthetic, geosynthetic and geosynthetic, goesynthetic and waste have been modeled with the interface element. The results gave a good agreement with the field large-scale model test. The relative displacements of geosynthetics were also investigated and hence the interface modeling of liner system is appropriate for analysis of geosynthetics liner system in the waste landfill.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.285-292
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• 2010

Recently, it is difficult to find a good soil ground due to the shortage of land for new construction site. Because of this situation, the geosynthetics are commonly used for reinforcing the substructure of the soil ground, and hence improving the bearing capacity and reducing the settlement. The geocell is one of geosynthetics and is the advanced system of geogrid. It is the way to increase earth strength and bearing capacity by using three dimension type of geocomposite. In this paper, the Horizontal permeability was determined with considering various geocell shapes. The permeability test was performed by following method of ASTM D4716(87) and potential filling material for geocell was used. The bearing capacity mechanism which enhances the soil ground with evenly maintaining the degree of the compaction was also analyzed for geocell reinforced ground.