• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6C
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• pp.385-393
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• 2006

Soil nailing is a reinforcement method used for stabilizing excavated walls or slopes. Due to its much advantages such as ease of construction and economical efficiency, use of soil nailing is increased. However, the soil nail has much disadvantages for use in urban area. The soil nail needs to be installed inevitably beyond private land boundary, which causes rent for use. For this reason, removable soil nailing system was developed. However, the removal rate of this system is just about 50￠¦70%. To resolve this problem, the Fiber Reinforced Plastic (FRP) soil nailing system which does not need to be removed and allows for the installation beyond private land, is developed. In this paper, through theoretical and experimental studies in laboratory and field such as prototype tests, pullout tests, we evaluate the stability and behavior characteristics of the FRP soil nailing system. And, numerical analyses using FLAC2D were performed with respect to various soil conditions, where prototype test for excavation wall and pullout tests were carried out. As a result of this study, the FRP soil nailing systems show similar behavior characteristics with those of removable soil nailing system. Finally, considering the serviceability and mechanical stability of FRP soil nailing systems, it is enough to be used as a good alternative of general soil nailing system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5963-5973
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• 2011

Current design and analyzing methods about soil nailing structures, developed on the basis of results obtained from experiments in laboratory or in field and numerical analyses, have applied different interaction mechanisms between the reinforced nails and the surrounding ground, and different safety factors against failure have been obtained. They might be proper approaches if the assumptions about rigidity of nails and ground conditions are met with actual conditions occurred in field. Otherwise, they would result in designing on analyzing in inappropriate ways so that it is needed to evaluate the validity of them. Therefore, in this research using the Centrifugal Model Testing, numerical parameters experiments about soil nailing structures' behavior and failure mechanism were performed. In the numerical parameters experiments, transmuted nail's length, setting angle, nail's front panel, stiffness variously, and increased the level of gravity until wall model was destroyed. Based on experimental results, we compared the effect, failure mechanism caused from parameters changes. By reviewing and comparing centrifugal model test results and methods currently in use, verified validity of existing methods.

• Geotechnical Engineering
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• v.11 no.1
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• pp.79-100
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• 1995

This paper proposes a stabilizing method against landslide using slide suppressor wall reinforced with soil nails. Included are a procedure to predict earth pressures acting on the concrete panel and a method of analysis of stabilizing pile. Based on the proposed procedure, the efficient installation type and inclusion angle of nails are analyzed. Also, optimum location of the slide suppressor wall composed of concrete panel and stabilizing pile is analyzed. Finally the comparison with a method proposed by Wright is made, and the effect of interactions between stabilizing piles is examined, throughout the design example.

• Mycobiology
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• v.34 no.4
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• pp.180-184
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• 2006

The mycobiota of 160 hair and nail samples collected from 4 different governorates in upper Egypt were estimated using soil plate method for isolating keratinophilic and dermatophytic fungi. Twenty-three fungi were recorded on both hair and nail samples collected from the four governorates. Highest fungal diversity (20) was collected from Red Sea samples followed by Qena (18) and Aswan (17) while lowest fungal diversity was recorded from Sohage samples. The common genera were Aphanoascus, Aspergillus, Penicillium, Paecilomyces and Chrysosporium. The most prevalent species belonging to these genera were: A. fulvescens, Aphanoascus sp. A. flavus link, A. flavus var. columnaris, P. chrysogenium. P. lilacinus and C. sulfureum. True dermatophytes such as Nannizzia fulva appeared in $20{\sim}30%$ of the male samples.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1081-1086
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• 2010

The general soil nailing support system may result in excessive deformations particularly in an excavation zone of the existing weak subsoils. Pretensioning the soil nails then, could play important roles to reduce deformations mainly in part of the nailed-soil excavation system as well as to improve local stability. Morever, soil nails are installed underneath roads, underground structures, and subway structures, thereby resulting in difficulties in nail remval after completion of temporary soil nailed walls. Hence, to date, in order to solve the technical difficulties and avoid legal issues related to the construction of soil nails underneath the surrounding areas and structures, the removable soil nailing system has been developed and used. But, Therefore, a new soil nailing technique called Removable Post-tensioned Soil Nailing(RPTN) system has been developed in the current study. In this study, an investigation of the RPTN system has been conducted by carrying out field measurement. Hence, the RPTN system can reduce ground displacement and enhance stability of the soil nailed walls.

• Geotechnical Engineering
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• v.13 no.2
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• pp.91-100
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• 1997

The soil nailing method has been developed on the basis of experimental works as well as theoretical backgrounds. As for the experimental research works, most of the data have been measured during the application of load in service. However, not only the soil-nailed structure behavior in service but also the failure behavior of the structure is major concern to evaluate and even establish a design method of soil-nailed walls. In this study, a relatively large-scale experiment was carried out to figure out the failure behavior of soil-nailed wall. A number of data such as displacement of soil-nailed walls, soil pressure in soil-nailed walls, atrial strain and axial force of nail etc.'have been acquired and analysis.

• Geotechnical Engineering
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• v.11 no.2
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• pp.79-98
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• 1995

In the present study an analytical modeling was carried out to predict mobilized shear strength at the interface between the nail and surrounding soils by carefully examining the behavior characteristics of nailed boil excavated walls. Based on the developed model of mobilized shear strength, the method of overall stability analysis of nailed -soil walls was also developed using the Morgentern -Price limit -equilibrium slice method. The developed analytical procedure could predict the behaviors of nailed -soil excavated walls during the successive excavation stages, at the final stage of construction and post -construction stages. To verify the validity of the developed model and method of stability analysis, mobilized tensile forces of nails and overal stability estimated by the developed procedure were compared with test measurements from three nailed -soil experimental walls having different soil conditions. The effect of seepage pressures inside the soil mass was considered in the developed procedure.

• Journal of Industrial Technology
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• v.19
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• pp.115-125
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• 1999

Current design and analyzing methods about soil nailing structures, developed on the basis of results obtained from experiments in laboratory or in field and numerical analyses, have applied different interaction mechanisms between the reinforced nails and the surrounding ground, and this different safety factors against failure have been obtained. They might be proper approached if the assumptions about rigidity of nails and ground conditions are met with actual conditions occurred in field. Otherwise, they would result in designing on analyzing in inappropriate ways so that it is needed to evaluate the validity of them. Therefore, overall behavior and failure mechanism about soil nailing system were investigated by performing numerical method. Using a finite element analysis, parametric studies were made to examine the importance of the various parameters and their effects on the soil nailing system. The numerical technique of FEM, implemented with Hyperbolic constitutive model, was also used to analyze the test results.

• Journal of the Korean Geotechnical Society
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• v.17 no.2
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• pp.103-111
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• 2001

지반네일 보강방법은 이론적 뒷받침과 함께 경험적인 작업을 기초로 발전되어 왔으며, 연구 결과를 바탕으로 현장적용이 활발하게 이루어지고 있다. 본 연구에서는 소일 네일로 보강된 토체의 안정성에 중요한 요소인 소일네일의 인발저항력을 높이기 위하여 네일의 끝 부분에 앵커와 같은 구근이 형성된 네일로 보강된 토체의 파괴거동을 이해하기 위하여 비교적 큰 규모의 실험을 실시하였다. 토체의 변위, 네일의 축변형률, 네일의 축하중, 토체내부의 토압 등에 관한 자료를 얻었으며 이러한 자료들을 분석하였다. 또한 같은 조건에서 일반적인 형태의 네일로 실험된 결과와 비교분석을 실시하였다.

• 기술발표회
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• s.2006
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• pp.135-145
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• 2006

Soil nailing systems are generally many used in underground excavations and reinforcements of slopes since the first construction as a temporary retaining wall in 1993, Korea. In recently, they are many attempts to expand the permanent reinforcements of slopes However, experimental studies related to soil nailing systems are insufficient Specially, there are no researches related in the large scaled load tests of soil nailed walls in Korea In this study, a case study on the large scaled load tests of soil nailed walls is introduced and the behavior characteristic of them is investigated Also, they are proposed allowable deformation corresponding to the serviceability limit of soil nail walls and ultimate deformation corresponding to the collapse state of the walls. These results can be applied to the maintenance management of soil nailed walls And analysis on the required minimum factor of safety of soil nailed walls using the relation curve of load ratio and deformation ratio are carried out