• 한국산학기술학회논문지
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• 제15권6호
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• pp.3923-3930
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• 2014

본 연구에서는 광양 ${\bigcirc}{\bigcirc}$산업단지 공사현장내의 도로 및 구조물 시공구간 중 연구대상 3구간을 선정하여 지반의 물리 역학적 특성을 분석하고 구조물 시공조건, 고화처리 단면조건에 따라 Midas-GTS를 통해 압밀해석과 지지력 산정을 수행하였다. 도로 및 구조물이 시공되는 연약점토지반의 침하 및 지지력 개선방안으로 고화처리공법 적용 시 지반의 안정성 개선효과와 고화처리단면에 따른 침하 및 지지력 개선효과를 분석하였다. 연약점토지반에 고화처리공법을 적용 시 침하 및 지지력 개선효과가 뛰어난 것으로 나타났으며 특히, 고화처리공법 적용 후 압밀침하량이 최소 53%에서 최대 82%까지 감소하여 압밀침하 억제효과가 우수한 것으로 나타났다. 고화처리 폭이 설치 구조물 폭의 2배 이상인 경우 고화처리 폭이 증가하여도 압밀침하 억제효과는 1~7%정도로 미소한 것으로 나타났다. 또한, 고화처리 폭 6m, 심도 1m이상 적용시 고화처리 전보다 허용지지력이 2.3~3.3배정도 크게 증가한 것으로 나타나 고화처리공법을 적용하면 지지력 증대효과가 매우 우수함을 알 수 있었다.

• International Journal of Railway
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• 제7권4호
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• pp.91-93
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• 2014

In these days, use of proper soils for construction materials become more limited, but wasted soils are abundant; therefore, the method which can use wasted soil such as soft clay has been investigated. Air-foamed stabilized soil has been used widely, but never been used as a subgrade material. The aim of this study is to verify the use of air-foamed stabilized soil as the subgrade construction material. Several wasted soils such as soft clay was selected to make air-foamed stabilized soil mixtures. The air-foamed stabilized mixture design was conducted to find the optimum quantity of stabilizing agent (cement) and air-foamed, and the effect of cement quantity and air-foamed quantity on strength of air-foamed stabilized soil mixtures base on the test results of unconfined compression test was investigated. As the quantity of cement is increased, the strength is increased, but the quantity of air-foamed is increased and the strength is decreased. Elastic moduli based on unconfined compression strength were obtained to use as subgrade of railway track design.

• Geomechanics and Engineering
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• 제23권1호
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• pp.31-38
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• 2020

Soil-cement stabilization is a type of ground improvement method which has been used to improve the engineering properties of soil. The unconfined compression test is the commonly used method to evaluate the quality of the stabilized soil due to its simplicity, reliability, rapidity and cost-effectiveness. The main objective of this study was to evaluate the effect of recovered carbon black (rCB) on the strength characteristic of cement-stabilized sand. Various rCB contents and water to cement ratios (w/c) were examined. The unconfined compression test on stabilized sand with different curing times was also conducted for a reconstituted specimen. From the test result, it was found that the compressive strength of cement-stabilized sand increased with the increase of the rCB content up to 3% and the curing time and with the decrease of the w/c ratio, showing that the optimum rCB concentration of the tested stabilized sand was around 3%. In addition, a prediction equation was suggested in this study for cement-stabilized sand with rCB as a function of the w/c ratio and rCB concentration at 14 and 28 days of curing.

• Geomechanics and Engineering
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• 제23권5호
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• pp.481-491
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• 2020

Piles installed in row(s) are used as an effective technique to improve the stability of soil slopes. The analysis of pile-stabilized slopes require a reliable prediction of lateral resistance offered by the piles. In this work, an analytical solution is developed to estimate the lateral resistance offered by the stabilizing piles in sand and c - 𝜙 soil slopes considering soil arching phenomenon. The soil arching in both horizontal direction (between the neighboring piles) and vertical direction (in the active wedge in front of the pile row) are studied and their effects are incorporated in the proposed model. The shape of soil arch is assumed to be circular and principal stress trajectories are defined separately for both modes of arching. Experimental and numerical studies found in literature were used to validate the proposed method. A detailed parametric analysis was performed to study the influence of pile diameter, center-to-center spacing, slope angle and angle of internal friction on the lateral pile resistance.

• 대한토목학회논문집
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• 제29권5C호
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• pp.229-237
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• 2009

전통적인 되메우기 방법은 모래 또는 현장발생토를 다짐하는 공법이 주로 사용되어 왔으나 이는 시간과 비용이 많이 든다. 특히 관의 하부 및 작은 틈새와 같은 부분은 전통적인 다짐 공법으로는 다지기가 난해하기 때문에, 이러한 문제점을 보완하기 위해 현장토를 재활용함으로써 모래 수급 문제를 해결하고 배합설계를 통해 유동성 및 강도를 임의로 조절할 수 있는 유동화 처리토 공법이 제안되었다. 본 연구에서는 현장토의 유기물 함유량에 따른 유동화 처리토의 배합 특성을 파악하고자, 휴믹산 함유량에 따른 재료분리특성, 유동성, 강도특성, 투수특성을 실내실험을 통해 측정하여, 비교 분석하였다. 그 결과, 휴믹산 함유량이 증가할수록 재료분리 특성과 유동성은 크게 나타났고, 강도는 유기물 함유량과 반비례하는 것으로 나타났다. 또한 유기물 함유량은 유동화 처리토의 투수특성에는 영향을 미치지 않는다는 것을 알 수 있었다.

• Advances in Computational Design
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• 제3권2호
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• pp.201-212
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• 2018

Decrease in availability of suitable subbase and base course materials for highway construction leads to a search for economic method of converting locally available troublesome soil to suitable one for highway construction. Present study insights on evaluation of benefits of stabilization of subgrade soils in term of extension in service life (TBR) and layer thickness reduction (LTR). Laboratory investigation consisting of Atterberg limit, Compaction, California Bearing Ratio, unconfined compressive strength and triaxial shear strength tests were carried out on two types of soil for varying percentages of stabilizers. Vertical compressive strains at the top of unstabilized and stabilized subgrade soils were found out by elastoplastic finite element analysis using commercial software ANSYS. The values of vertical compressive strains at the top of unstabilized and stabilized subgrade, were further used to estimate layer thickness reduction or extension in service life of the pavement due to stabilization. Finite element modeling of the flexible pavement layered structure provides modern technology and sophisticated characterization of materials that can be accommodated in the analysis and enhances the reliability for the prediction of pavement response for improved design methodology. If the pavement section is kept same for unstabilized and stabilized subgrade soils, pavement resting on lime, fly ash and fiber stabilized subgrade soil B will have service life 2.84, 1.84 and 1.67 times than that of unstabilized pavement respectively. The flexible pavement resting on stabilized subgrade is beneficial in reducing the construction material. Actual savings would depend on the option exercised by the designer for reducing the thickness of an individual layer.

• 한국지하수토양환경학회지:지하수토양환경
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• 제29권1호
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• pp.10-17
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• 2024

In Korea, the common remedial process for reclamation of agricultural soils nearby abandoned mines involves chemical soil stabilization followed by covering with clean soil. This study investigated the chemical properties of cover soils and the validity of HCl extraction method in assessing the degree of As and heavy metal stabilization in stabilized soils collected from 14 plots where mine reclamation had been completed. The results revealed there were no major differences in contaminants extraction rate between the stabilized soils and contaminated soils, suggesting HCl extraction procedure is a less feasible method to determine the efficiency of the stabilization. Soil quality indicators including OM, SiO₂, P₂O₅, etc. of the land-covering soils were generally lower than those of stabilized soils that used to be the cultivation layer before the stabilization. Nonetheless, the value of those indicators didn't meet the regulatry limits of agricultural soil. Therefore, future strategy for mine reclamation should concentrate not only on contaminant concentration but also on soil quality parameters for agricultural use of the reclaimed soil.

• 문화기술의 융합
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• 제8권3호
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• pp.457-462
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• 2022

본 연구는 순환자원을 대량 활용한 지반안정재를 활용하여, 비교적 작은 하중이 작용하는 중·저층 건축물의 얕은 기초 보강공법에 적용한 사례에 대한 내용으로 우선하여 현장 최적배합비를 도출하고자 4가지 혼합비에 대한 실내배합시험을 실시하였으며, 도출된 최적배합비를 이용하여 현장에서 건축물 얕은기초로 적용하였다. 현장 적용방법은 원지반와 지반안정재를 교반한 혼합토를 현장에서 혼합하여 다짐을 실시하는 매우 단순한 공정을 이용하였다. 현장 적용 후 평판재하시험을 원지반 1곳, 개량지반 2곳에 실시하여 허용지지력을 확인하였다. 지지력 확인 결과 충분한 지지력을 발휘하는 것으로 나타나, 해당 건축물의 앝은기초로 활용이 가능한 것으로 확인되었다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회 2차
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• pp.192-199
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• 2010

This research produced internal model tester ($2.0m{\times}2.0m{\times}1.0m$) to evaluate the field application of Paju Unjeong District water recycling system for small streams eco-friendly river bed disparity method for the first time in Korea and conducted comparative analysis of the Paju Unjeong District water recycling system field test results and infiltration rate result of internal tests by each rainfall intensity following surface material. Infiltration rate result of internal tests concrete pavement by rainfall intensity following surface material, asphalt pavement, bentonite mate, stabilized soil construction and mixed soil construction manifested low infiltration rate. On the contrary, compaction soil, grassland and water permeable packaging materials resulted in significant amount of infiltration rate. As for the field permeability test results, they were manifested similar tendency as indoor permeability test results and they satisfied the standard for standard of water permeability of domestic disparity facility (less than $1.0{\times}10-7cm$/sec). As compaction rate increased, unconfined compression strength increased as well while coefficient of water permeability decreased.

• Geomechanics and Engineering
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• 제20권3호
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• pp.207-220
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• 2020

Clay soils have a big potential to become contaminated with the oil derivatives because they cover a vast area of the earth. The oil derivatives diffusion in the soil lead to soil contamination and changes the physical and mechanical properties of the soil specially clay soils. Soil stabilization by using new material is very important for geotechnical engineers in order to improve the engineering properties of the soil. The main subjects of this research are a- to investigate the effect of the cement and epoxy resin mixtures on the stabilization and on the mechanical parameters as well as the microstructural properties of clay soils contaminated with gasoline and kerosene, b- study on the phenomenon of clay concrete development. Practical engineering indexes such as Unconfined Compressive Strength (UCS), elastic modulus, toughness, elastic and plastic strains are all obtained during the course of experiments and are used to determine the optimum amount of additives (cement and epoxy resin) to reach a practical stabilization method. Microstructural tests were also conducted on the specimens to study the changes in the nature and texture of the soil. Results obtained indicated that by adding epoxy resin to the contaminated soil specimens, the strength and deformational properties are increased from 100 to 1500 times as that of original soils. Further, the UCS of some stabilized specimens reached 40 MPa which exceeded the strength of normal concrete. It is interesting to note that, in contrast to the normal concrete, the strength and deformational properties of such stabilized specimens (including UCS, toughness and strain at failure) are simultaneously increased which further indicate on suitability and applicability of the current stabilization method. It was also observed that increasing cement additive to the soil has negligible effect on the contaminated soils stabilized by epoxy resin. In addition, the epoxy resin showed a very good and satisfactory workability for the weakest and the most sensitive soils contaminated with oil derivatives.