• Title/Summary/Keyword: Surface stabilizing

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Reinforcement Effect of Stabilizing Piles in Large-scale Cut Slops (대절토사면에 보강된 억지말뚝의 활동억지효과에 관한 연구)

  • 홍원표;한중근;송영석;신도순
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.06a
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    • pp.65-81
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    • 2003
  • During the last few decades in Korea, the development of hillside or mountain areas has rapidly increased for infrastructure construction such as railroads, highways and housing. Many landslides have occurred during these constructions. Also, the amount and scale of damage caused by landslides have increased every year. In the case of Far East Asia including Korea, the damage of landslides is consequently reported during the wet season. In this paper, the effect of stabilizing piles on slope stability is checked and the behavior of slope soil and piles are observed throughout the year by field measurements in the large-scale cut slopes. In particular a large-scale cut slope situated on the construction site for the express highway in Donghae, Korea. First of all, The behavior of the slope soil was measured by inclinometers during slope modification. Landslides occurred in this area due to the soil cutting for slope modification. The horizontal deformations of slope soil gradually increased and rapidly decreased at depth of sliding surface indicating that the depth of sliding surface below the ground surface can be predicted. On the basis of being able to predict the depth of the sliding surface, stabilizing piles were designed and constructed in this slope. To ensure the stability of the reinforced slope using stabilizing piles, an instrumentation system was installed. The maximum deflection of piles is measured at the pile head and it is noted that the piles deform like deflection on a cantilever beam. The maximum bending stress of piles is measured at the soil layer. The pile above the soil layer is subjected to lateral earth pressure due to driving force of the slope, while pile below soil layer is subjected to subgrade reaction against pile deflection. As a result of research, the effect and applicability of stabilizing piles in large-scale cut slopes could be confirmed sufficiently.

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Effect of Lumbar Stabilizing Taping on The Electromyographic Activation of Trunk and Gluteal Muscles During One-Leg Standing (한발 서기 동작 시 요부 안정화 테이핑이 체간부와 고관절 주위근의 근활성도에 미치는영향)

  • Jeong, Ki-Yong;Kim, Suhn-Yeop
    • Journal of Korean Physical Therapy Science
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    • v.17 no.1_2
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    • pp.23-32
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    • 2010
  • Purpose: The purpose of this study was to investigate trunk and gluteal muscle activation during one-leg standing or two-leg standing with lumbar stabilizing taping using non-elastic tape. Method: The subjects of this study were twenty subjects(man=11, women=9) who be in good physical health and have not problem to back muscle and one leg standing. The surface electromyographic(EMG) data were recorded on external oblique(EO), gluteus medius(GMed), gluteus maximus(GMax), quadratus lumborum(QL) while pre- and post-lumbar stabilizing taping in two-leg standing and one-leg standing. The analysis of data was performed using the paired samples t-test to compare the difference of EMG activity of pre and post lumbar stabilizing taping. Result: Contrast of pre-lumbar stabilizing taping the muscle activity of QL in post-lumbar stabilizing taping is significant decrease on two-leg standing posture(p<.05), and the muscle activity of GMed is significant increase on one-leg standing posture(p<.05). Thus, we suggest that lumbar stabilizing taping using by functional tape will be able to affect on lumbar stability and gluteal muscle retraining.

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Shadow Mask 제조공정의 열변형특성(I)

  • 손순식;서윤철;강충길
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1997.10a
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    • pp.102-109
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    • 1997
  • The surface deformation of shadow mask was studied by the experiments and numerical analysis for process improvement and delet of the stabilizing process in the shadow mask manufaturing line. To inverigate the thermal deformation of shadow mask with and without stabilizing process mask, data of spring strength, frame flatness, frame magnetic force and a mask surface curvature were measured. The tube characteristics of two kind of shadow masks were also investigated.

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The Behavior of Stabilizing Piles installed in a Large-Scale Cut Slope (대규모 절개사면에 설치된 억지말뚝의 거동)

  • Song, Young-Suk;Hong, Won-Pyo
    • The Journal of Engineering Geology
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    • v.19 no.2
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    • pp.191-203
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    • 2009
  • The effect of stabilizing piles on cut slopes is checked and the behavior of slope soil and piles are observed throughout the year by field measurements on the large-scale cut slopes. First of all, the behavior of the slope soil was measured by inclinometers during slope modification. Landslides occurred in this area due to the soil cutting for slope modification. The horizontal deformations of slope soil are gradually increased and rapidly decreased at depth of sliding surface. As the result of measuring deformation, the depth of sliding surface below the ground surface can be known. Based on the measuring the depth of the sliding surface, some earth retention system including stabilizing piles were designed and constructed in this slope. To check the stability of the reinforced slope using stabilizing piles, an instrumentation system was installed. As the result of instrumentation, the maximum deflection of piles is measured at the pile head. It is noted that the piles deform like deflection on a cantilever beam. The maximum bending stress of piles is measured at the soil layer. The pile above the soil layer is subjected to lateral earth pressure due to driving force of the slope, while pile below soil layer is subjected to subgrade reaction against pile deflection. The deflection of piles is increased during cutting slope in front of piles for the construction of soil nailing. As a result of research, the effect and applicability of stabilizing piles in large-scale cut slopes could be confirmed sufficiently.

Analysis of Slope Behavior Using FBG Sensor and Inclinometer (광섬유 센서와 지중경사계를 이용한 사면의 거동 분석)

  • 장기태;한희수;유병선
    • Journal of the Korean Geotechnical Society
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    • v.19 no.6
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    • pp.397-406
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    • 2003
  • Several sensor systems are used to estimate the reinforcing effect of stabilizing pile in slopes, and to find a failure surface in slopes effectively. FBG(Fiber Brags Crating) sensor, V/W(Vibrating Wire) sensor and inclinometer have shown a great potentiality to serve real time health monitoring of the reinforcing structures. Field tests and test results have shown great solutions for sensor systems of Smart Structures. The purpose of this research is to seek for the relationships among the slope movement and the reinforcing effect of stabilizing pile, and the strain distribution of stabilizing pile in a active zone by analyzing the data from the in-situ measurement so that the possible failure surface should be well defined based on the relationships. The field test results have shown that the data by FBG sensor are well coincided with those of V/W sensor and inclinometer, and the reinforcing effect of the stabilizing pile is good enough.

Effects of Stabilizing Additives on Electroless Copper Deposition (무전해 동 도금용액 속에서 안정제의 역할)

  • 최순돈;박범동
    • Journal of Surface Science and Engineering
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    • v.25 no.4
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    • pp.173-180
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    • 1992
  • The effects of the stabilizing additives such as NaCN, 2-MBT and Thiourea on bath decom-position, plating rate and surface morphology have been studied. Bath stability was increased in the order of an additive-free bath, and NaCN-, 2-MBT-, and Thiourea-stabilized baths. The sta-bilizing effects may be attributed to the stability of Cu(II) -complexes. The plating rate is the re-verse order of the bath stability. Accelerative effect of 2-MBT in proper quantity(0.3mg/$\ell$) may be explained by visualizing it absorbed through benzene ring or sulfur atom on portions of the sub-strates. The strong bond of the complexing part of the molecule to nearby chelated copper ions would tend to accelerate plating by making it easier for the Cu2+ -ligand bond to be broken. Sur-face morphologies of copper deposits depend on the bath additives. Electroless copper deposits from the 2-MBT stabilized baths are finer than the deposits from the NaCN- and Thiourea- stabi-lized baths due to the strong adsorption on the substrates.

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Efficient Unit-Water Management Method for Stabilizing the Quality of Ready-mixed Concrete (레미콘 품질 안정화를 위한 효율적인 단위수량 관리 방안)

  • Choi, Sung-Woo;Ryu, Deug-Hyun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.05a
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    • pp.327-328
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    • 2021
  • In the manufacturing process of ready-mixed concrete, quantity management directly affects the workability and strength of concrete. Therefore, water quantity is the most important management factor for water quality control of ready-mixed concrete. It can be said that the number of unit water in the mix design, the water quantity due to the surface water contained in the aggregate used, and the water quantity taking into account the concentration of sludge contained in the recycling water when using the recycling water are factors that affect the quantity management of ready-mixed concrete. In this study, as a stable quality control method of ready-mixed concrete, a quantity management method by aggregate surface water and a sludge concentration management method according to the use of recycling water were proposed. Thus, we tried to suggest an efficient quantity management method for stabilizing the quality of ready-mixed concrete.

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Flow Control Inside a Molten Zn Pot for Improving Surface Quality of Zinc Plated Strips (아연도금강판의 품질향상을 위한 도금욕 내부 유동제어 연구)

  • Choi, Jae-Ho;Koh, Min-Seok;Kim, Seok;Lee, Sang-Joon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.25 no.10
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    • pp.1392-1399
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    • 2001
  • The flow fields inside a molten Zn pot of continuous hot-chip galvanizing process were investigated experimentally. With varying several parameters including the strip speed Vs, flow rate Q of induction heater. scrapper location and baffle configuration, instantaneous velocity fields were measured using a PIV velocity field measurement technique. Inside the strip region, counter-clockwise rotating flow is dominant. The general flow pattern inside the strip region is nearly not influenced by the strip speed Vs, flow rate Q and the scrapper location. In the exit region, the flow separated from the moving strip due to the existence of a stabilizing roll ascends to the free surface, for the cases of no scrapper and scrapper detached form the roll. On the other hand, the ascending flow to the free surface is decreased, as the flow rate Q of induction heater increases. By installing a baffle around the uprising strip, the flow moving up to the stabilizing roll decreases. In addition, B-type baffle is better than A-type baffle in reducing speed of flow around the stabilizing rolls. However, the flow ascended to the free surface is largely influenced by changing the flow rate Q, and the scrapper location, irrespective of the baffle type.

An Experimental Study on the Reinforcement Effect of Installed composite stiffener on Earth Retaining Walls using Stabilizing Piles (억지말뚝 흙막이공법에 설치된 복합버팀의 보강효과에 관한 실험적 연구)

  • Kim, Tae-Hyo;Im, Jong-Chul;Park, Lee-Keun;Kwon, Joung-Keun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.1224-1239
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    • 2008
  • The earth retaining walls using stabilizing piles can be applied to shallow excavation works without any stiffener. But, It demends a variety of installed composite stiffener on the earth retaining walls when it is installed as deep excavation works. Because, it causes an excessive displacement of walls. This research tried to overcome the problems created by the above issues and intended to apply the composite stiffener. The model test, focused on the effect of installed composite stiffener, measured the bending stress with stabilizing piles and walls, the settlement of earth surface, the displacement of walls for a step excavation and an increase in strip load. With the test results and soil deformation analysis, the reinforcement effect(relating to control displacement and earth presure) was analyzed in a qualitative and quantitative manner. It is expected to overcome a deep excavation works.

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Surface-modified Cellulose Nanofibril Surfactants for Stabilizing Oil-in-Water Emulsions and Producing Polymeric Particles (표면 개질된 나노피브릴화 셀룰로오스를 이용한 에멀젼 안정화 및 고분자 입자 제조)

  • Kim, Bo-Young;Moon, Jiyeon;Yoo, Myong Jae;Kim, Seonmin;Kim, Jeongah;Yang, Hyunseung
    • Applied Chemistry for Engineering
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    • v.32 no.1
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    • pp.110-116
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    • 2021
  • In this work, the surface of hydrophilic cellulose nanofibrils (CNFs) was modified precisely by varying amounts of cetyltrimethylammonium bromide (CTAB) to produce CNF-based particle surfactants. We found that a critical CTAB density was required to generate amphiphilic CTAB-grafted CNF (CNF-CTAB). Compared to pristine CNF, CNF-CTAB was highly efficient at stabilizing oil-in-water Pickering emulsions. To evaluate their effectiveness as particle surfactants, the surface coverage of oil-in-water emulsion droplets was determined by changing the CNF-CTAB concentration in the aqueous phase. Furthermore, styrene-in-water stabilized by CNF-CTAB surfactants was thermally polymerized to produce CNF-stabilized polystyrene (PS) particles, offering a great potential for various applications including pharmaceuticals, cosmetics, and petrochemicals.