• Journal of the Korean Geotechnical Society
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• v.15 no.6
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• pp.131-142
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• 1999

The objective of this study is to perform finite element analyses using the anisotropic hardening constitutive model on the basis of the total stress concept. An anisotropic hardening constitutive model had been developed in a companion paper, and was then formulated by implicit stress integration and consistent tangent moduli. A nonlinear finite element analysis program was coded including the algorithm, and as a result, the nonlinear solution was accurately calculated and converged to be asymptotically quadratic. In the analysis of a test embankment it was found that the proposed model could predict the displacement of soils more reasonably than the analysis with von Mises type model. In addition the proposed model could predict accurately the actual behavior through the reanalysis of the problem by a reasonable evaluation of the strength parameter.

• Journal of the Korean Geotechnical Society
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• v.39 no.7
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• pp.49-56
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• 2023

Gravel is commonly employed to enhance the bearing capacity of foundations and provide stable support for structures. However, effectively assessing the ground characteristics in the presence of gravel poses significant challenges. This study aims to compare the resolution of ground containing gravel using electrical resistivity, elastic wave surveys, and ground penetration radar (GPR). Nondestructive methods are applied at construction sites where soil improvement is carried out using gravel. The experiments focus on shallow depths, and the obtained results cover depths up to 2 m. Both the electrical resistivity and elastic wave techniques exhibit similar behavior in their findings, indicating comparable outcomes. However, GPR has limitations in observing the characteristics of ground with gravel. Dynamic cone-penetration tests were conducted to validate these findings. The electrical resistivity and elastic wave profiles exhibited similar behaviors in localized areas, further supporting their compatibility and reliability.

• Journal of the Korean Geosynthetics Society
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• v.17 no.2
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• pp.41-49
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• 2018

The purpose of this study is to fabricate a full scale road embankment using lightweight air foamed soil as a soil material on soft ground and to investigate its material characteristics and behavior in order to promote dredged soil utilization and minimize ground improvement. As a result of the laboratory test of the onsite mixed samples, the total unit weight of the specimens decreased almost linearly until curing 28 days. In particular, the total unit weight after 28 days of curing was reduced to about 81% of the slurry state before curing, which will be useful in the formulation of similar native soil materials in the future. The unconfined compressive strength began to decrease with the 14th day of curing as shown in the previous study. When the cement content is increased, the strength decreases sharply at a small strain change after the occurrence of the maximum compressive strength, and the maximum strength is exhibited in a range of a smaller axial strain than normal range. The settlement at the surface layer of the ground due to the lightweight embankment was about 1 / 2.75 of the soil embankment and was in agreement with the unit weight ratio (1 / 2.7) of the embankment materials. This indicates the cause and effect of the settlement due to the difference in self weight of the embankments. Also, the difference in settlement between soil and lightweight embankment increased with increasing depth. This shows that the difference in the point at which the settlement is terminated is clear. The ground horizontal displacement under the lightweight embankment was about 15~20% smaller than that of the soil embankment and the depth of occurrence was also 4.5~5.0m shallower in the lightweight embankment.

• Journal of the Korean GEO-environmental Society
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• v.15 no.1
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• pp.43-51
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• 2014

Angular distortion due to differential settlement is one of the critical factors which influences on the stability and serviceability of a structure. The angular distortion criterion proposed by Bjerrum is generally used in practice. However, the measurement system used in field especially a road embankment site did not properly represent the angular distortion of a structure. The problem was related to the shortage and not proper installation of measurement gauges, and the incorrect understanding of the basic concept of angular distortion in interpretation of measurement data. These things were reveled by analyzing the measured data in the road embankment site. An improved measurement system has been suggested as a so-called "relative displacement measurement system" between columns with automatic measurement.

• Journal of the Korean Geotechnical Society
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• v.20 no.2
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• pp.97-105
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• 2004

The purpose of this study is to provide the ways of recycling of by-product limes as lightweight fill, backfill materials, and lightweight blocks by performing experimental study. New lightweight fill materials and blocks were devised by mixing by-product lime, weathered granite soil, small pieces of waste EPS, and Portland cement. Physical, geotechnical, and environmental properties of the lightweight mixed soils and blocks were analysed by laboratory experiments for mixed samples manufactured with various mixing ratios. KMS tests were also performed to evaluate the concentration variation of the chemical components of the light weight blocks leachates. It is expected that this study will contribute to resolving the problem of by-product lime disposal as well as to recycling the by-product limes as fill materials and blocks.

• Korean Journal of Agricultural Science
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• v.25 no.2
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• pp.247-259
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• 1998

Analyses which loads were regarded as instant load and gradual step load were performed with data measured on gradually loaded field, and the results were inspected to find effect of load condition, and final settlements predicted by Hyperbolic, Tan's, Asaoka's, and Monden's method were compared with each other. According to above analyses, the following conclusions were obtained. Settlement curves which loads were regarded as instant load and gradual step load were beginning to coincide at time of twice duration of embankment. On the ground installed vertical drain, the result of Hyperbolic, Tan's, Asaoka's, Monden's, curve fitting I, and curve fitting II (simple, Carrillo) methods make conclude that Asaoka, curve fitting I, and curve fitting II methods agree with measured settlement.

• Journal of the Korean Geotechnical Society
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• v.22 no.3
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• pp.13-21
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• 2006

Geosynthetic damage has attracted a major attention since the introduction of geotextiles for civil engineering applications. In this study 3 pilot trial embankments were carried out to investigate the behaviours of reinforced embankments over soft cohesive soils and to find the optimum methodology of embankments over soft soils. As the seamed part of polyester mat (PET, tensile strength 15 ton) used in the first full-scale field test was ruptured under progressing rotational slope failure because of unexpectedly rapid construction of embankments, the excessive pore water pressures were measured. On the soil behavior where tension explosion of mat was continued, pore pressure larger than the one caused by embankment height was measured. Especially, at the depth of 5.0 m under the ground pore pressure increased over long term. It was discussed with respect to the height of embankment and heaving behavior of soft soils.

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.265-268
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• 2003

댐(dam)의 기초지반에 시공되는 그라우트 커텐(grout curtain)은 댐 축조 후 기초지반을 통한 침투류를 차단하기 위하여 시행되며, 콘크리트 댐, 흙 댐, 사력 댐 등의 공학적 차이에 따라서 그 시공 위치 및 심도, 폭 등이 다르게 적용된다. 그라우트 커텐(grout curtain)의 설계ㆍ시공 요소는 기초지반의 투수성, 댐 내의 수심, 제체 성토재료의 투수성, 그라우트 커텐의 투수성 등에 의하여 결정되며, 설계 시공 요소들은 그라우팅 커텐의 길이, 폭, 투수도 등이다. (중략)

• Journal of the Korean GEO-environmental Society
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• v.4 no.4
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• pp.61-71
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• 2003

On the soft soil consisted of silty clay, the compulsion replacement method is useful for revetment and its safety is very much affected by compulsion replacement depth. Usual method calculating the compulsion replacement depth on silty clay is considered the bearing capacity of soft soil with undrained shear strength increase from ground surface and weight of revetment. But according to soil deposit, there are some cases of soft soil with inter sand layer or clayed silt, which affect the compulsion replacement depth. In this paper, the compulsion replacement depth on soft soil with inter sand layer is analyzed by layered weighted average bearing capacity considering influence effect of Perloff et al.(1967) and compared with numerical method(FLAC). In the result, the calculated depth from numerical method is nearest to layered weighted average bearing capacity in case that contact width under revetment is $0.2B_o$(soft soil with inter sand layer), $0.5B_o$(only soft soil) and the effect of contact width under revetment is less than undrained shear strength, thickness and location of inter sand layer. Also the compulsion replacement depth is as much as the inter sand thickness($d_2/B_o$) is thinner, the inter sand layer location($d_1/B_o$) is farther, and undrained shear strength is less.

• Journal of the Korean GEO-environmental Society
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• v.3 no.2
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• pp.61-70
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• 2002

This paper presents the engineering property of light weight soil made of soil mixed with recycled Styrofoam and stabilizer. Recycled Styrofoam is widely used for lightweight fill material because it has important geotechnical characteristics which are light, adiabatic, and effective for vibration interception. It is very easy to get the disposal styrofoam. For this study, dynamic compaction test, static compaction test and pH and leaching tests were performed. Based on the test results, it is concluded that the static compaction method is recommened to prevent from crushing materials and pH values of embankment materials are satisfied with these of domestic and RCRA configuration.