• Proceedings of the Korean Geotechical Society Conference
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• 2000.09a
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• pp.73-78
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• 2000

The reinforced soil has been widely used for constructing retaining walls and embankment with steep slope. However, the benefits of soil reinforcing are often-restricted by a lack of good quality backfill material. In this study, plane strain compression tests were carried out to study the effects of preloading on the behavior of geosynthetic-reinforced saturated clay. For the unreinforced and reinforced soil, drained and undrained shearing tests were peformed after anisotropic consolidation in a constant strain rate. A preoading test was carried out by preloading, creep, unloading, aging and undrained shearing after anisotropic consolidation(K=0.3, σ'₃=50 kPa). It was observed that a reinforced clay, Kanto loam, can have a great initial secant modulus in undraind condition by well compaction and over consolidation. The results shown that the increasing of drained strength should be used to apply a large preloading in the case of reinforced clay.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.6
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• pp.81-90
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• 2008

Recently, geofiber(polyester) reinforced soil was added on soil-seed mixture spray to control erosion and to improve vegetation growth on rocky slope sites. This research was conducted to compare vegetation effects and soil hardness on three types of soil-seed mixture spray on stone gabion river bank [A type : soil-seed mixture spray underlying 30cm thick sand with geofiber(geofiber reinforced soil system), B type : soil-seed mixture spray underlying 30cm thick sand without geofiber, C type : soil-seed mixture spray]. Evaluation were made concerning vegetation coverage, soil hardness and moisture content. The results of this study showed that A type system was effective for the growth of vegetation and soil hardness when compareed to B type and C type. A type and B type showed higher covering rate than C type on stone gabion river bank, and especially A type showed the highest covering rate. Soil hardness and water content were high on A type vegetation system compared to B type and C type. We noted that high soil hardness and high moisture content with geofiber(geofiber reinforced soil system) were effective both to control erosion from water current impact and to be high coverage and species of vegetation on stone gabion river bank.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.06a
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• pp.13-19
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• 2001

The use of reinforced soil have been increased due to it's cost effectiveness, flexibility and so on. In this study, a full-scale reinforced soil with rigid facing were constructed to investigate the soil pressure variation of reinforcing system. The results of soil pressure during backfill construction are described. The influence of facing stiffness on soil pressure is addressed. The results show that lateral earth pressures on the wall are active state during backfill. It is obtained that the lateral soil pressure highly depends on the installation condition of pressure cell and construction condition. Long-term measurement will be followed to verify the design assumptions with respect to the distribution of lateral stress on the facing.

• Geomechanics and Engineering
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• v.2 no.1
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• pp.19-28
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• 2010

This paper describes the compaction and strength behavior of black cotton soil (BC soil) reinforced with coir fibers. Coir used in this study is processed fiber from the husk of coconuts. BC soil reinforced with coir fiber shows only marginal increase in the strength of soil, inhibiting its use for ground improvement. In order to further increase the strength of the soil-coir fiber combination, optimum percentage of 4% of lime is added. The effect of aspect ratio, percentage fiber on the behavior of the composite soil specimen with curing is isolated and studied. It is found that strength properties of optimum combination of BC soil-lime specimens reinforced with coir fibers is appreciably better than untreated BC soil or BC soil alone with coir fiber. Lime treatment in BC soil improves strength but it imparts brittleness in soil specimen. BC soil treated with 4% lime and reinforced with coir fiber shows ductility behavior before and after failure. An optimum fiber content of 1% (by weight) with aspect ratio of 20 for fiber was recommended for strengthening BC soil.

• Proceedings of the Korean Geotechical Society Conference
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• 1993.10a
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• pp.23-28
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• 1993

Shearing properties of soil reinforced with discrete randomly oriented inclusions depend on soil density, particle size, grading, fiber length, tensile strength and stiffness of fiber, mixing ration of fiber, confining stress, etc.. In this paper the effects of those various factors on shear strength of the fiber-reinforced soil was evaluated through triaxial tests and uniaxial tests. Tests were performed on two sandy soils and one silty soil with inclusions in varing lengths, contents and tensile strengths and tested at different confining stresses in triaxial test. From the experimental results, it was investigated if there is an optimal range of fiber lengths and fiber contents for the tested soils.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.465-472
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• 1999

A small scale model reinforced soil wall was constructed in a laboratory to investigate role of the wall facing and the effect of construction sequence on the wall. A panel type facing system and a block facing system are introduced for test. These two different types of facing adapt different construction procedure. The model wall is built with geogrid reinforcement, sand, and the facings on rigid surface. The model wall is instrumented with earth pressure gauges, LVDTs, and strain gauges. It is found in this study that the reinforced soil wall system built with geogrids and panel type facing system be the safest reinforced soil wall ever compared to the block type facing. Thus, it is recommended that study for the wall system be necessary for further wide usage in the future.

• Journal of the Korean Geotechnical Society
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• v.22 no.7
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• pp.37-44
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• 2006

This paper investigates strength characteristics and stress-strain behaviors of geogrid mixing reinforced lightweight soil. The lightweight soil was reinforced with geogrid in order to increase its compressive strength. Test specimens were fabricated by various mixing conditions including cement content, initial water content, air content and geogrid layer and then unconfined compression tests were carried out. From the experimental results, it was found that unconfined compressive strength as well as stress-strain behavior of lightweight soil was strongly influenced by mixing conditions. The more cement content that is added to the mixture, the greater its unconfined compressive strength. However, the more initial water content or the more air foam content, the less its unconfined compressive strength. It was observed that the compressive strength of reinforced lightweight soil increased reinforcing effect by the geogrid for most cases. Stress-strain relation of geogrid mixing reinforced lightweight soil showed a ductile behavior rather than a brittle behavior. In reinforced lightweight soil, secant modulus ($E_{50}$) also increased as its compressive strength increased due to the inclusion of geogrid.

• Journal of the Korean Geosynthetics Society
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• v.4 no.4
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• pp.47-56
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• 2005

With the need of efficient site use retaining walls have frequently used. Of them dry cast modular block wall(MBW), in which geogrid and concrete block are used is getting popular because of its simplicity and economical efficiency of construction. However, since this method is based on the theory of earth pressure, sands with good quality should be used. In contrast, reinforced soil slope(RSS) that the slope is less than $70^{\circ}$ can use wider range of soil than MBW. A hybrid reinforced geo-structure might be a good alternative in view of overcoming difficulty obtaining soils with good quality as well as maximizing the efficiency of site use. This method is composed of reinforced block wall and reinforced soil slope. In this method, reinforced block wall is constructed up to a certain height vertically at ground boundary first. Reinforced soil slope is then constructed on the block wall subsequently. This paper introduces several technical points that should be taken into account in design and construction.

• Journal of the Korean Geosynthetics Society
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• v.5 no.3
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• pp.17-24
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• 2006

This paper presents the two field walls that demonstrate the effect of rainfall on the performance of soil-reinforced retaining wall. A field test wall constructed in Geotechnical Experimental Site at Sungkyunkwan University has been monitored for more than 8 months to study the long-term behavior of soil-reinforced retaining wall. The measured data showed a good correlation between rainfall and wall movement after wall completion. A case of failed soil-reinforced retaining wall also is presented to highlight the effect of rainfall on the performance of soil-reinforced retaining wall. Implications of the findings are discussed.

• Journal of the Korean Geosynthetics Society
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• v.2 no.3
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• pp.47-55
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• 2003

This paper presents the two field walls that demonstrate the effect of rainfall on the performance of soil-reinforced retaining wall. A field test wall constructed in Geotechnical Experimental Site at Sungkyunkwan University has been monitored for more than 8 months to study the long-term behavior of soil-reinforced retaining wall. The measured data showed a good correlation between rainfall and wall movement after wall completion. A case of failed soil-reinforced retaining wall also is presented to highlight the effect of rainfall on the performance of soil-reinforced retaining wall. Implications of the findings are discussed.