• Title/Summary/Keyword: Soil nails

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Diversity of Keratinophilic Fungi on Human Hairs and Nails at Four Governorates in Upper Egypt

  • Gherbawy Youssuf A.M.H.;Maghraby Thanaa A.;El-Sharony Hassan M.;Hussein Mohmaed A.
    • 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.

A Distribution of Keratinophilic Fungi Isolated from the Soil of Haeundae Beach in Korea (부산 해운대 백사장에서 분리한 각질친화성 피부사상균의 분포)

  • Kim, Sojin;Kim, Su Jung
    • Korean Journal of Clinical Laboratory Science
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    • v.48 no.4
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    • pp.343-347
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    • 2016
  • Keratinophilic fungus (KPF), a type of dermatophytes, is usually present as normal flora on the skin of humans and animals but can produce ring worm-like dermatophytosis by invading the skin in infected individuals. They are distributed worldwide, but their occurrences vary distinctively in accordance with the geographical location and environmental change. Because these fungi grow by degrading keratin, they are abundantly found on the skin, hair, and nails, which are rich in keratin. To investigate the presence of keratinophilic fungi in the soil, we selected a popular beach in South Korea, Haeundae Beach, where numerous people gather each year during the summer holidays. Hundred soil samples were analyzed using the hair-baiting technique, among which, a total of 23 colonies of KPF were identified from 21 soil samples. The identified KPF were Microsporum gypseum (43%), Chrysosporium spp. (35%), Trichophyton ajelloi (13%), and Microsporum cookie (9%). This study confirmed that pathogenic fungi can be found in places crowded by many people. Further research and continuous data collection are needed to confirm the distribution of pathogenic KPF.

Analytical Evaluation on Soil Slope Reinforced by Pressure Grouted Protrusion Type Soil Nailing (가압식 돌기네일에 의해 보강된 토사 비탈면의 해석적 평가)

  • Hong, Cheor-Hwa;Lee, Sang-Duk
    • Journal of the Korean Geotechnical Society
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    • v.33 no.7
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    • pp.5-16
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    • 2017
  • Soil nailing is the most general method to reinforce the slope by taking pullout and shear resistance force of the nail for stabilizing the slope. Domestic soil nailing design method considers only pullout resistance and does not consider the shear resistance sufficiently. In case of nail, the effect of tensile stress is dominant, but it is desirable to design by considering shear stress as well as tensile stress in case of slope where circle failures occur. Recently, studies on the shear resistance effect of nails have been carried out in the geotechnical field. However, many researches on the shear reinforcement effect of soil nailing have not been conducted until now. Most of the studies are about increasing pullout resistance by improving material, shape and construction method of nail. Therefore, it is necessary to the study on shear resistance of soil nailing and development of new methods to increase the shear force. In this study, large shear test and limit equilibrium analysis have been performed for a new soil nailing method to increase the shear resistance by forming protrusions through pressurized grouting after installing a packer on the outside of deformed bar. The study results showed that shear resistance of protrusion type soil nailing increased compared to soil nailing and it is more effective when applied to the ground with large strength parameters.

Axial Stress Evaluation of Bundle Nails in Smart Construction (스마트 건설기반 번들네일의 축응력 평가)

  • Donghyuk Lee;Jaekoo Ryu
    • Journal of the Korean GEO-environmental Society
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    • v.25 no.6
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    • pp.13-17
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    • 2024
  • The general soil nailing method, which is currently used domestically and internationally to stabilize the slopes of sandy slopes, is to form a kind of gravity-type retaining wall by drilling the ground and grouting it with a single steel bar. This method can reduce construction costs, ease of construction, relative strength and displacement, and is highly efficient. The difference between grouting and rebar adhesion to the yield pullout force and the difference between the amount of deformation in relation to the same pullout resistance was analyzed through field tests to identify engineering excellence, and in terms of construction cost, the reduction effect was evaluated by analyzing the difference in the number of drillings and the impact on the overall construction cost, such as material cost, when the same strength constant is applied to the ground with the same resistance.

A Study on the Restraint Effect on Lateral Displacement of an Inclined Earth Retaining Structure Integrated with Soil Nailing in Sandy Ground (사질토지반에 설치된 소일네일 복합형 IER의 수평변위 억제효과에 관한 연구)

  • Park, Tae-Keon;Im, Jong-Chul;Yoo, Jae-Won;Kim, Chang-Young;Kang, Sang-Kyun;Lee, Woo-Je
    • Journal of the Korean Geotechnical Society
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    • v.33 no.10
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    • pp.33-47
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    • 2017
  • A self-supported temporary excavation method called IER is normally applicable to excavation depth ranging from 6.0 m to 7.0 m though the method depends on ground condition and overburden load. Combining IER with another method is required in deeper excavation depth in order to maintain the structural stability of the IER. In this study, we performed model tests and 3D FE analysis to check the stability of the IER adopting soil nailing method, and to propose its effective installation method. The lateral displacement of the IER using soil nailing decreased by 92% of that of IER without soil nailing. Optimum design is possible for both economic feasibility and stability when interval spacing and length of soil nails is $1.5m(S_h){\times}0.75m(S_v)$ and 86% of excavation depth, respectively. Excavation depth using IER increases 1.71 times by adopting soil nailing in increment of lateral displacement of IER right before the last excavation stage.

Application and its Reinforcing Effect of Soil Nailed-drilled Shafts (쏘일 네일(soil nail)로 보강된 현장타설말뚝의 적용성 및 보강효과 분석)

  • 김병철;이대수;김대홍;정상섬;김대학
    • Journal of the Korean Geotechnical Society
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    • v.20 no.5
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    • pp.87-98
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    • 2004
  • In this study reinforcing effect of soil nailed-drilled shafts subjected to axial and lateral loads was evaluated. Special attention was given to the reinforcing effects of soil nails placed from the drilled shafts to surrounding weathered- and soft-rocks based on model tests, numerical analyses and field tests. The model tests and numerical analyses are conducted to analyze the reinforcing effect of various conditions of number, inclination, position and length. The results of 1/40 scale model tests and numerical analyses show that as the number of reinforcing level increases, the incremental effect of reinforcement tends to increase, whereas the reinforcing effect on relative position is negligible. In addition there is a reinforcing effect as the inclination angle increase up to 30 degrees. Based on the results of tensile load tests, soil nailed-drilled shaft has a considerably smaller settlement to reach the ultimate level compared with the result of un-reinforced drilled shafts. For compression tests, there is a reinforcing effect of about 200% measured.

An Analysis on the Failure Mechanism of Slope behind a Plant Complex of Gimhae due to Typhoon Rusa (태풍 루사에 의한 김해 OO단지 사면붕괴 발생원인 분석)

  • Kang, In-Kyu;Ryu, Jeong-Soo;Kim, Hong-Taek;Baek, Seung-Cheol
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.263-266
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    • 2007
  • In this paper, analysis results on the failure of slope behind a Plant Complex of Gimhae due to typhoon Rusa in 2002 are introduced. The left side of the slope was reinforced by soil nails and the right side of the slope was going to construct slope reinforcement works. In the slope failure, the damage area is about $34,000m^2$, the lower width of slope failure is about 230m, the upper width of slope failure is about 50m, and the height of slope failure is about 120m. The elevation of a bedrock in the right side of the slope was lower than the left side of the slope. Due to the depth of weathered soils and weathered rocks in right side of the slope was thick, it will be expected that the effects of pore-water pressure during the rainfalls are large. For the analysis of the failure mechanism, 3-dimensional numerical analysis was carried out by FLAC-3D.

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Three-Dimensional Limit Equilibrium Stability Analysis of the Irregularly Shaped Excavation Comer with Skew Soil Nailing System

  • Kim, Hong Taek;Par
    • Geotechnical Engineering
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    • v.14 no.3
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    • pp.73-94
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    • 1998
  • In the present study, a method of the three-dimensional limit equilibrium stability analysis of shape of the potential failure wedge for the concave-shaped excavation corner is assumed on the basis of the results of the FLACSU program analysis. Estimation of the three-dimensional seepage forces expected to act on the failure wedge is made by solving the three-dimensional continuity equation of flow with appropriate boundary conditions. By using the proposed method of three-dimensional stability analysis of the concave-shaped excavation corner, a parametric study is performed to examine the reinforcement effect of skew soil nailing system, range of the efficient skew angles and seepage effect on the overall stability. Also examined is the effect of an existence of the right-angled excavation corner on three-dimensional deflection behaviors of the convex-shaped skew soil nailing walls. The results of analyses of the convexshaped excavation corner with skew soil nailing system is further included to illustrate the effects of various design parameters for typical patterns of skew nails reinforcement system.

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Optimum Reinforcement Conditions of Large Diameter Reinforcement for Steep Slope of Conventional Railway Embankment under Train Loading (기존선 성토사면 급구배화를 위한 열차 하중 하 대구경 봉상보강재의 최적 보강조건)

  • Kwak, Chang-Won;Kim, Dae-Sang
    • Journal of the Korean Geotechnical Society
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    • v.32 no.11
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    • pp.43-50
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    • 2016
  • A reinforcement is required to ensure the structural safety in case of railway embankment excavation under railway load. A large diameter soil nailing with concrete wall is applied as the reinforcement method instead of the conventional soil nailing system. In this study, a series of 3 dimensional numerical analyses are performed to investigate the optimum reinforcement considering 15 different conditions based on the length, lateral spacing, diameter, and inclination of the reinforcement. The interface between soil nail and perimetric grout is considered by means of cohesion, stiffness and perimeter of the grout. 0.3 m of reinforcement diameter is assessed as the most appropriate based on the economical viewpoint though ground displacement decreases with the increase of diameter, however the difference of displacement is negligible between 0.4 m and 0.3 m of diameter. Surface settlement, lateral displacement of wall, and stress of reinforcement are calculated and economic viewpoint to reinforce embankment considered. Consequently, the optimum reinforcement conditions considering those factors are evaluated as 3 m in length, 0.3 m in diameter, 1.5 m in lateral spacing, and 10 degree of inclination angle in the case of 3 m of excavation depth. Additionally, inclined potential failure surface occurs with approximately 60 degrees from the end of nails and the surface settlement and wall lateral displacement are restrained successfully by the large diameter soil nailing, based on the result of shear strain rate.

Interpretation of Making Techniques and Material Characteristics for Molding Clay of Four Guardian Statues in Wanju Songkwangsa Temple, Korea (완주 송광사 소조사천왕상의 재질특성 및 제작기법 해석)

  • Han, Doo Roo;Lee, Chan Hee;Jo, Young Hoon
    • Journal of Conservation Science
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    • v.28 no.4
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    • pp.353-366
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    • 2012
  • This study was interpreted the making techniques of the Four Guardian Statues in Wanju Songkwangsa Temple, and retained basic data necessary for conservation treatment and restoration of the same material by estimating the soil source. The molding clay used in the Statues showed a variety of material characteristics according to different layers. The first and mid layers estimated as the original molding clay are composed of the same kind of soil. The soil of the finish layer was also confirmed to be genetically similar to that of the first and mid layers, despite little discrepancy. The former restoration layer was inconsistent in material characteristics with the original molding clay in every result of analysis. As a result of gamma radiography, making techniques of the Statues were able to identify the figure of the frame connecting the woods of main pillar frame to sub-frame and steel wire with ㄷ-clamp, nails and straw ropes, and the molding clay constructed upon the frame. Meanwhile, provenance interpretation confirmed that the soil of the estimated provenance area is of the same origin as the soil of the finish layer, and therefore is an appropriate material for conservation treatment. This result will contribute to the research on making techniques of the molding clay Statues.