• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1029-1036
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• 2009

Seapage condition by sea water may appears on sea dike due to the gap of tidal, which generated by the sealevel repeatedly moves up and down result of the change of tidal level. In this study, apparatus was developed to apply similitude after setting the critical section. It was found that the soil loss was dramatically increased by increasing hydraulic gradient step by step. Also, to understand the change of seadike which considered the changes of the change of tidal level and inside sealevel, it was executed the experiments which divided the sea level condition of inside by continually changes the sealevel difference which is outside of the high tide and ebb tide.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.156-157
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• 2014

Inorganic binding material was made by recycled resource and its applicability as pile-filling material was examined. The result was that the material had same liquidity with the liquidity of OPC and high reactivity with site soil. According to dynamic/static loading tests by site test-construction, the inorganic binding material met both design bearing capacity and settlement. Since the inorganic binding material showed same or better performance than OPC, the utilization possibility of the inorganic binding material made of recycled resource as pile-filling material was verified.

• Geomechanics and Engineering
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• v.4 no.2
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• pp.91-103
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• 2012

Focusing on the effect of excess pore pressure dissipation on liquefaction-induced ground deformation, a series of 1-g shaking table tests were conducted in a rigid soil container by use of saturated Toyoura sand, the relative density of which was 20-60%. These tests were subjected to the sinusoidal base shaking with step increased accelerations: 100, 200, 300 and 400 Gals for 2-4 seconds. Shaking table tests were done using either water or polymer fluid with more viscous than water, thus varying the sand permeability of model tests. Excess pore pressures, accelerations, settlements and lateral deformations were measured in each test. Test results are presented in this paper and the effect of sand permeability on liquefaction and liquefaction-induced ground deformation was discussed in detail.

• 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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.8-10
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• 2013

Inorganic binding material was made by recycled resource and its applicability as pile-filling material was examined. The result was that the material had same liquidity with the liquidity of OPC and high reactivity with site soil. According to dynamic/static loading tests by site test-construction, the inorganic binding material met both design bearing capacity and settlement. Since the inorganic binding material showed same or better performance than OPC, the utilization possibility of the inorganic binding material made of recycled resource as pile-filling material was verified.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.257-259
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• 2003

Landuse maps are prepared from satellite imagery and field observations were conducted at various locations in the study area. Compared to the field data and NDVI and RVI thematic maps, NDVI is better than RVI, because it compensates for changing illumination conditions, surface slope, aspect and other factors. Clouds, water and snow have negative values for RVI and NDVI. Rock and bare soils have similar reflectance in both NIR and visible band, so RVI and NDVI are near zero. In forest areas with good vegetation cover, NDVI is high and landslide occurrence is less. But if annual and biennial vegetations are present and if cultivation practices are changed frequently, NDVI is medium and landslide occurrence is moderate. In areas where deforestation and settlement is in progress, NDVI is less and landslide occurrence is more. The NDVI FCC thematic map may be used as an important layer in GIS application for landslide studies. Analyzing other layers such as slope, rainfall, soil, geology, drainage, lineament, etc with NDVI FCC layer will give a better idea about the identity of landslide prone areas.

• Geomechanics and Engineering
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• v.38 no.1
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• pp.79-91
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• 2024

The settlement, bearing capacity, axial force, and skin friction responses of pervious and impervious concrete piles in silty and sandy underlying layer foundations and of pervious concrete piles in model tests were determined. The results showed that pervious concrete piles can exhibit high strengths, provide drainage paths and thus reduce foundation consolidation time. Increasing the soil layer thickness and pile length could eliminate the bearing capacity difference of pervious piles in a foundation with a silty underlying layer. The pervious concrete piles in the sandy underlying layer were more efficacious than those in the silty underlying layer because the sandy underlying layer can provide more bearing capacity than the silty underlying layer. The results indicated that the performances of the pervious concrete piles in the sand and silt foundations differed. The pervious concrete piles functioned as floating piles in the underlying layer with a lower bearing capacity and as end-bearing piles in the underlying layer with a higher bearing capacity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4588-4594
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• 2014

In this study, small scaled (1/30) laboratory chamber tests of the pile foundation for a lightweight concrete pavement system were carried out to evaluate the safety of a pile foundation on sandy soil. The testing ground was simulated in the field and a standard pile-loading test was conducted. The test piles were divided into 3 types, Cases A, B and C, which is the location from the center of the slab by applying a vertical load. The interval between the piles was set to 8 cm. As a result of the pile foundation model test, the pavement settled when the vertical load was increased to 12kg from 1.5kg in sandy soil ground, particularly the maximum settlement of 0.04mm. Judging from the model chamber test, Case A showed compressive deformation, whereas Case B represented the compression and tensile forces with increasing vertical load. Case C showed an increase in tensile strain.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.1
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• pp.1-13
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• 2006

The recent environmental protection issue has diminished the supply of sand for soft ground improvements so much that the prices of sand have shown a sudden rise. Plastic material is one of substitutes for sand material, but plastic is nonperishable and doubtable if it has potential environmental hormone disrupting substances. Moderate-priced natural fiber drain board made with coconut coir and jute filter are in the spotlight recently as an alternative material for sand and plastic drain board etc. Natural fiber drain has not only competitive price but also a characteristic of assimilation into the soils after finishing of its own function. Discharge capacity of the fiber drain board evaluated by triaxial type discharge capacity test was relatively lower than that of plastic drain board. Nevertheless, settlement and pore pressure dissipation behaviors of the fiber drain board and the plastic drain board which were installed in the clayey soil during the composite discharge capacity test were almost similar. It was also found that biodegradation of the fiber drain board was in progress until 18 month after installation in the clayey soil, but they had still enough engineering properties to use at field.

• Journal of Korean Society of Disaster and Security
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• v.7 no.2
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• pp.1-8
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• 2014

Smart Pole Measurement System was constructed with not only the core sensors of a GNSS receiver, a TRS sensor and a soil moisture sensor but supplementary installation of power supply and radio communication for monitoring steep slope sites. Also a data processing software for displacement extraction and visualization was developed. Smart Pole Measurement sensor is composed of a GNSS antenna at the top of the pole, a TRS sensor and a gyro sensor vertical below right of the antenna and a soil moisture sensor at the bottom of the pole. The sensor combination extracts not only ground combination in real time but transltion, slide, settlement and soil moisture content. This measuring/monitoring system which cosists of data receiving part, data collection/transfer part and data processing part was built to exercise their functions and then test measuring/monitoring was conducted by introducing artificial displacement and the results were analyzed to evaluate field applicability.