• Title/Summary/Keyword: Nail inclination

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The Effects of Nail Inclination in Soil Nailing by Finite Element Analysis (유한요소해석에 의한 쏘일네일링의 네일 경사각의 영향에 관한 연구)

  • 천병식;김원철;윤창기
    • Journal of the Korean Geotechnical Society
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    • v.20 no.6
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    • pp.19-27
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    • 2004
  • Since the first construction of soil nailing in France in 1972, the application of soil nailing has increased. However, there is currently no design method which is universally accepted or agreed upon far soil nailed wall, because each of the design methods has different assumptions and, therefore, different approaches, moreover, since the suggested optimal inclination angles of nails are different by researchers. Therefore, the effect of nail inclination with soil nailing is analyzed by FEM. In this study, Finite element program SOILSTRUCT was applied for the effect analysis of nail inclination in soil nailed wall. For this finite element analysis, CEBTP No. 1 project data were used. The analyzed nail inclination ranged from 0$^{\circ}$ to 30$^{\circ}$ with 5$^{\circ}$ intervals. The result of finite element analysis showed that the most optimal inclination was 20$^{\circ}$ Also, the tension farce in the nails increased as the nail inclination increased. However, the effect of nail inclination on the wall deformation was very little. Therefore, constructability seems to be more important than nail inclination. Also, the tension force in the nails increases as the nail depth below the top of the wall increases, except f3r the lowest nail. Therefore, appropriate nail diameter should be used to prevent breakage of nails with considering nail strength-deformation interaction.

A Study on the Design Applicability of Soil Nailing Using Limit Equilibrium Analysis and Finite Element Model (한계평형 및 FEM 해석을 통한 Soil Nailing의 설계 적용성에 관한 연구)

  • Kim, Won-Cheul;Chun, Byung-Sik;Yoon, Chang-Ki;Park, Shin-Young
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.301-310
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    • 2004
  • The several computer programs for the design of soil nailed wall are often used in Korea. However, these programs have been used without and practical justification. Therefore, in order to evaluate the applicability of these programs for the design of soil nailing, these computer results were analyzed and compared with one another. The performance evaluations by the available programs, such as SNAILZ, TALREN97, SLOPE/W STABL6, and NAILMI6, were applied and the applied data were from 6 case history(21 section). The estimated factors of safety with available programs were compared with observed horizontal deformation from the field. This study showed that the program SNAILZ is most adequate tool for the design of soil nailed wall. Also, The finite element program SOILSTRUCT was applied for the analysis of nail inclination effect in soil nailed wall. The program SOILSTRUCT showed that the most optimal inclination of nail was $20^{\circ}$. However, the effect of nail inclination on the wall deformation was negligible. Also, the tension force of the nail were increased as the nail inclination increased, and the tension force of the nail increased as the depth increased, except the deepest nail. Therefore, the larger diameter nail should be considered if the inclination of nail is steeper than the suggested range, and the deeper nails should have the larger diameters than those of shallower nails except for the deepest one.

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Factor of Safety of Local Instability in Soil Nail Slopes (쏘일네일이 보강된 사면의 국부파괴에 대한 안전율 분석)

  • Koy, Channarith;Kim, Beom-Jun;Jang, Hyun-Ick;Lee, Sang-Rae;Yune, Chan-Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.38 no.3
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    • pp.449-456
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    • 2018
  • In this study, a soil nail design method for a stability analysis of local instability with nail reinforced slope was proposed. The failure mechanism of a local instability of slope was studied and a theoretical equation to estimate the stability of slope was developed. Using the developed equation, the stability analysis was performed according to installation conditions of soil nail such as a slope inclination, a thickness of soil layer, a nail inclination, and a nail spacing. Considering those design factors, a sensitivity analysis for each influence factors was conducted. Analysis results showed that the safety factor of reinforced slope with nail was higher than the slope without nail. In addition, the safety factor of slope according to ground condition was increased in the order of dry, saturated, and seepage condition.

Load Transfer Analysis of Drilled Shafts Reinforced by Soil Nails (Soil Nail로 보강된 현장타설말뚝의 하중전이 분석)

  • 정상섬;함홍규;이대수
    • Journal of the Korean Geotechnical Society
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    • v.20 no.1
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    • pp.37-47
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    • 2004
  • In this study the load distribution and settlement of soil nailed-drilled shafts subjected to axial loads were evaluated by a load-transfer approach. Special attention was given to the reinforcing effects of soil nails placed from the shafts to surrounding weathered- and soft-rocks based on an analytical study and a numerical analysis. An analytical method that takes into account the number, the positions on the shaft, the grade, and the inclination angle at which the soil nails are placed was developed using a load transfer curve methods. Through the comparative study, it is found that the prediction by present approach simulates well the general trends observed by the in-situ measurements and numerical results SHAFT 4.0. It is also found that the reinforcing effects of soil nails increases in the order of hard-, soft- and weathered-rock since the ultimate shaft resistance far large bored piles in weathered rocks is fully mobilized after small displacements of the shaft, compared to the soft- and hard-rocks and subsequently the side resistance is transferred down to the soil nails.

The Effect of Nail Inclination of soil Nailing Structure of vertically Faced Wall (벽체가 수직인 쏘일네일링 구조물의 네일 경사각 영향)

  • Han, Sang-Su;Baek, Yong;Kwon, O-Il;Kim, Young-Nam;Chae, Young-Su;Lee, Kang-Il
    • The Journal of Engineering Geology
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    • v.18 no.3
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    • pp.277-285
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    • 2008
  • For the soil nailing, recently, its application is expanded, but there is no officially approved method to design it yet. Furthermore, there are a great number of design valuables in soil nailing, it is also used without clear data under the situation that uncompleted detailed research on the sensibility between design variables. Especially, there has no deal with the installation angle of the nail - the major contents in this study. Therefore, this study based on the theoretical estimation analyzed safety rate about the angle of the nail, unit weight, adhesive force, internal friction angle and tensile farce worked on nail in the case of the rear of pond side is both horizontal and perpendicular. As a result, it could be verified that the safety rate increased on every cases in the situation of the nail installation angle was in upward direction than in downward direction.

Model Tests of Soil Nailing System under Surcharges (상재하중 하의 Soil Nailing System의 모형실험)

  • Yoo, Nam-Jae;Yoo, Kun-Sun;Kim, Jae-II
    • Journal of Industrial Technology
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    • v.14
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    • pp.77-87
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    • 1994
  • This research is an experimental work of investigating the behavior of soil nailing system under surcharges whereas most of them were concentrated on evaluating its capacity under selfweight of excavated ground. Model tests in laboratory were performed to investigate the ultimate bearing capacity of soil nailing system under surcharges in forms of strip loading. Tests were carried out to find parameters controlling its capacity such as length of nail, vertical and horizontal spacings between nails, inclination of nail installation, and loading position of surcharges. Failure mechanism of forming failure line due to surcharge to soil nailing system was also observed by using dyed sand and monitoring its behavior. From results of these test, effects of parameters was analyzed qualitatively. Thus, this experimental results could provide meaningful data to analyze and design this system later.

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Rationale and criteria for excellent finishing (양호한 Finishing을 위한 이론적 근거 및 기준)

  • Ryu, Young-Kyu;Kim, Young-Joon
    • The korean journal of orthodontics
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    • v.29 no.6 s.77
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    • pp.637-648
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    • 1999
  • Finishing is usually accomplished about four to seven months before the removal of orthodontic appliance in order to achieve ideal occlusion and excellent aesthetics. This process, called finishing, is the key to obtain excellent final results. Some of orthodontists believe it can be accomplished at the final stage of orthodontic treatment, and they complete it without their special rationale and criteria for finishing. However, it should be considered as a part of the total treatment plan from the beginning to end, and a guideline for finishing, which is based on rationale and criteria for the removal of orthodontic appliance, is needed to obtain the desired results. The guideline should include a checklist for finishing. This checklist is divided into four categories: occlusal, aesthetic, periodontal, and habitual factors. Occlusal fators include alignment, marginal ridge discrepancy, interproximal contact, anterior inclination, posterior inclination, over-jet over-bite, arch fen and functional occlusion. Aesthetic factors include gingival form, crown fen crown width, and crown length. Periodontal factors include root angulation, bone level, and black hole in periodontal factors. Habitual factors consist of mouth breathing, tongue position at rest, tongue thrust, lip biting, nail biting, and finger sucking

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Application and its reinforcing effect of soil nailed-drilled shafts (Soil Nail로 보강된 현장타설말뚝의 적용성 및 보강효과 분석)

  • Jeong, Sang-Seom;Kim, Byung-Chul;Lee, Dae-Soo;Kim, Dae-Hong;Kim, Dae-Hak
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.50-57
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    • 2004
  • In this study reinforcing effect of soil nailed-drilled shafts subjected to axial and lateral loads were 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 load 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 increaes up to 30 degrees. Based on the results of tensile load tests, soil nailed-drilled shafts has a considerably smaller settlement to reach the ultimate level when compared with the result of un-reinforced drilled shafts. For compression tests, there is a reinforcing effect of about 200% measured.

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An Analysis of Design Factors for Developing Opuntia Humifusa Spines Removal Device

  • Jang, Ik Joo;Ha, Yu Shin
    • Journal of Biosystems Engineering
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    • v.38 no.3
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    • pp.215-221
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    • 2013
  • Purpose: Opuntia Humifusa has been used in the food and beauty industry after removing spines and glochids clearly. This study compared the methods used in removing spines and analyzed the design factors for developing a spine removal device. Method: This study compared the spine removal ratios in accordance with the length of brush, water spray pressure, the number of water spray, and the size of Opuntia Humifusa in a rotating brush device and a water spray device. In addition, this study compared the reversal ratios according to the inclination angle of a conveyor, the drop height of Opuntia Humifusa, and the speed of the conveyor to analyze the reversal factors. Results: The spines were not removed clearly in the rotating brush method, and the glochids were nailed deeply. The spine removal ratio was 96.9% with the water spray pressure of 20 $kgf/cm^2$ and the conveyor speed of 10 cm/s in the water spray method. The number of water spray was correlated with the spine removal ratio, and the average spine removal ratio was 95.6% with three cycles of water spray. The reversal ratio was 97% with the inclination angle of the conveyor $20^{\circ}$, the drop height of 380 mm, and the conveyor speed of 10 cm/s. Conclusions: In order to develop a Opuntia humifusa spine removing device, this study compared the rotating brush and water spray methods. As a result, each spine removal performance of the rotating brush and water spray methods was 96.9% and 95.6%, respectively. Although the performance of the rotating brush method was slightly higher than that of the water spray method, the water spray method was suitable for removing spines from stem because the epidermis of stem was damaged and the glochids were nail deeply in the rotating brush method. Further studies on appropriate arrangement of spray nozzles, maintaining the optimal water spray pressure, the speed and angle control of the feeding conveyor, and devices for inducing the stem to the center will be needed in combining the water spray device and the reversal device.

A Study on the Influences of LOHAS Consciousness on LOHAS Cuticle Management (로하스 의식이 로하스 큐티클 관리에 미치는 영향)

  • Cho, Youn-Hee;Kim, Soon-Shim
    • Journal of the Korea Fashion and Costume Design Association
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    • v.14 no.2
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    • pp.215-227
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    • 2012
  • This study aims to analyze the influences of LOHAS cuticle management, which based on LOHAS consciousness among customers using nail art shops and removes only Cuticle layer without Eponychium, on the preference and expected value of service quality. Further, it tackles how above related variables have important bearing on reuse intention. A survey was conducted only with customers over the age of 20 in Seoul, Daejeon and Daegu areas in terms of LOHAS consciousness. For the collected 389 data, frequency analysis, t-test, ANOVA, correlation analysis and multiple regression analysis were carried out by using SPSS 18.0 Version statistical package. The results are as follows. First, according to the results, it shows high positive correlation between LOHAS cuticle management based on the consciousness of LOHAS, and LOHAS cuticle management preference, tendency and willingness to transfer toward it. Second. it is proven that LOHAS consciousness tend to be possessed in older age groups, married and a professional employee layers and this LOHAS motivated groups showed high LOHAS cuticle management preference, inclination and intention of a change in management. Lastly, the reuse intention is mostly affected by experience and preference of LOHAS cuticle management. There is negative correlation between reuse intention and experience in blooding and pain during care service. Higher interest in preference of LOHAS cuticle management has highly influenced positive link with the repurchase intention.

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