• Journal of the Korean Geotechnical Society
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• v.17 no.1
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• pp.131-139
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• 2001

화강토와 관련된 지반문제의 거동예측을 위한 수치해석의 적용이 양적인 면에서는 많이 확대되어왔지만 해석결과에 지대한 영향을 미치는 구성방정식 등 수치해석 모델링을 개선하고자 하는 노력은 부족하였다. 화강토 거동의 특징은 내재적 결합력으로 인한 구조화의 거동을 나타내는 것이며, 항복면이 평균유효응력 축에 대칭이고 Non-associated 소성거동을 보인다는 점이다. 본 연구에서는 이러한 화강토 거동을 표현하기 위하여 일반화된 한계상태모델을 도입하고, 이를 화강토의 경화거동 모델링이 가능하도록 확장하였다. 제안된 모델을 이용한 삼축시험의 유한요소 시뮬레이션 결과는 측정결과와 좋은 일치를 보였다. 화강토 지반내 터널에 대한 유한요소해석을 수행한 결과, 비선형 탄성모델과 조합된 확장된 한계상태모델이 현장계측결과와 잘 일치하는 결과를 주었다.

• Geotechnical Engineering
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• v.12 no.5
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• pp.137-154
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• 1996

Pull-out tests for three different types of strip reinforcements are performed to investigate variation of the apparent coefficient of friction which occurs between the reinforcements and the weathered granite soils with different contents of fine materials. The contents of fine materials for the soil sample are varied from 7% to 36% and the reinforcements used for the pullout tests are smooth, ribbed steel strips and a textured shape Paraweb 1 Friction tie. Test results show that the apparent coefficient of friction tends to decrease with the increase of the content of fine meterials. It is known, however, that the minimum apparent coefficient of friction required to the design of reinforced earth structures can be achieved even at 35% fine contents by using appropriate reinforcements. The ribbed strip reinforcement is found to be the most effective in mobilizing the apparent friction when interacting to finer weathered granite soils. The textured reinforcement is also useful for 35% fine con tents if the textured depth is increased.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.6
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• pp.120-126
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• 2018

The study conducted an experiment in which residual aggregate and polypropylene fibers are mixed in concrete, and an experiment in which granite and polypropylene fibers are mixed. Two types of experiments, in particular, changed the amount of polypropylene fibers, and examined the mechanical properties of slump, compressive strength, tensile strength and the like. To establish a light and easy-to-use material for landscape construction and packaging material development by comparing two kinds of experimental results, comparing and analyzing residual aggregate as experimental materials and materials using granite soil to prevent partial destruction due to cracks in drying shrinkage. The more the amount of the PP fibers increases in concrete, the more the volume of the PP fibers increases, the less the slump is determined. As a result of the compressive strength, the cast-down earth concrete is measured to be about 59% to 71% of the concrete strength. As the amount of PP fibers mixed in increased, the compression strength showed a relative decrease. As a result of tensile strength, it is found that the granite concrete is about 68-67% of concrete tensile strength. It was found that the compression strength decreased as the amount of PP fibers mixed in concrete or fire-gant concrete was increased. Then, when polypropylene fibers are mixed in the concrete and the concrete, it is found that tensile strength is increased. By analyzing these results, a fixed amount of PP fiber is mixed in the concrete mixed with the granite soil and utilized for various structures in the field of landscape construction or materials related to packaging, the prevention and improvement effect of the structure is determined.

• Geotechnical Engineering
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• v.12 no.1
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• pp.63-72
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• 1996

The current practice in construction of reinforced earth retaining walls is to use a granular soil for the backfill material. When the material is available in site, the construetion cost can be remarkably reduced. As the weathered granite soils are abundant and widely distributed throughout the Korean peninsula: whether they are suitable or not as the backfill material is considered to be the most important key in economic construction of the wall. This paper investigates the grain size distribution of the weathered soils which locate at many places throughout the nation and then examines limitation of their use based on the specifications of different countries. The variaton of shear strength with both different fine contents and saturation is also investigated. It is known that the grain size distribution of most weathered soils are not satisfied with the general requirement. However their use is possible in wide range when the backfill keeps in unsaturated condition using good drainage facilities and 1 or pervious reinforcements.

• Journal of the Korean GEO-environmental Society
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• v.13 no.8
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• pp.45-55
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• 2012

This study is about the application of waste stone sludge as fill material. Waste stone sludge, weathered granite soil, and the mixture of the former and the latter strengthened with staple fiber are experimentally analyzed for measuring strength property. When staple fiber was mixed with waste stone sludge, weathered granite soil, and the mixture, there was a nearly linear relationship between the amount of the staple fiber and the increasing ratio of unconfined compressive strength. The increasing ratio of unconfined compressive strength was the largest in weathered granite soil. The increasing ratio of unconfined compressive strength of the mixture was similar to that of waste stone sludge. In the case of the mixture of weathered granite soil and waste stone sludge, an internal friction angle tended to increases rely on increasement of staple fiber content, whereas the change of cohesion was small. An internal friction angle was increased by 21 percent when staple fiber content is 0.75 percent. Comparing with weathered granite soil or waste stone sludge, strength parameters of the mixture were increased relatively. Thus strengthening effect of staple fiber in the mixture is expected.

• Water for future
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• v.8 no.2
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• pp.25-25
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• 1975

• Geotechnical Engineering
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• v.12 no.2
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• pp.107-114
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• 1996

A series of shear tests is performed to measure friction coefficients of the interface between different reinforcements and weathered granite soils. The reinforcements tested are smooth steel strip, Paraweb(friction tie) and geotextile with rough surface, while the weathered granite soils are composed of different, grain size distribution. Soils are compacted with the energy of 95% modified AASHTO and fully saturated before testing to simulate the worst site condition. Because of characteristics of the direct shear apparatus, shear strength is obtained in terms of drained condition. Test results show that the more fines the soils contain, the larger ratio of friction coefficient ($\mu=\frac{tan{\delta}}{tan{\Psi}}$) is obtained. Also the ratios are much higher for the Friction tie and the geotextile compared to the smooth steel strip. Those suggest that even weathered granite soils with 36% fines are possible to use as backfill of reinforced earth structures for the two reinforcements when a drainage system is provided.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2C
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• pp.117-123
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• 2008

Disturbed and undisturbed decomposed granite soils with different weathering degrees were extracted and analyzed through a series of tests (CD test, constant P test, etc.) to assess their dilatancy characteristics. Here, dilatancy refers to the volume change that takes place during shearing. As a result, the decomposed granite soil dilatancy impact increased the mean effective stress while concurrently lowering the water content in drained shear tests. In the case of undisturbed decomposed granite soil, which has a lower weathering degree, the water content increased at specific limits during the shearing process. A linear relationship of ${\Delta}V_d/V_1=D{\cdot}(({\sigma}_1-{\sigma}_3)-{\sigma}_c)/{{\sigma}_m}^{\prime}$ forms between shearing-induced volume change and principal stress variance.

• The Journal of Engineering Geology
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• v.12 no.4
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• pp.459-469
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• 2002

We have remolded marine clay sample collected along the vertical and horizontal directions and investigated the characteristics of the consolidation constants by SCT and CRSC methods. We have studied also on consolidation chracteristics and application for weathered granite soil using SCT and CRSC methods for undisturbed and disturbed samples. As the result, values of pre-consolidation stress, compression index, excessive pore pressure, pore water pressure ratio of the marine-clay were different due to different test methods(SCT and CRSC) and sampling directions(vortical and horizontal directions). Disturbed and undisturbed samples of the weathered granite soil have showed similar change aspect like marine clay during over-consolidatied and normally consolidatied stages.

• Proceedings of the Korean Geotechical Society Conference
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• 1998.03a
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• pp.32-66
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• 1998