• Title/Summary/Keyword: reinforcement condition

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경부고속철도(대구-부산) 도심통과 노반신설 공사중 기존 지하철 터널구간의 구조적 안정성 검토 (Structure stability study for existing subway tunnel segment of Seoul-Busan high-speed railroad (Daegu - Busan) construction)

  • 공병승;김민호
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 춘계학술대회 논문집
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    • pp.1752-1759
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    • 2007
  • In the new Seoul-Busan high speed railroad construction specially city center passage roadbed establishment is recommended the staibility for the existing subway tunnel segments of Busan subway line No. 1 and No.2. regarding the appearance condition, a quality condition and the durability of the objective facility site exact inspection, and it evaluates the numerical analysis which uses MIDAS GTS it leads and there is the objective of the place where the stability of the objective facility and this tunnel it investigates. To immediacy of the on-the-spot inspection result whole facility it is a condition where the reinforcement which is simple not to be hindrance is necessary, 2nd Line case it is a condition which transfer is good but the general defect and the damage which occur from the tunnel of NATM type were confirmed part. While roadbed establishment constructing that the continuous maintenance is necessary, it is judged. The result of 1st, 2nd Line maximum sinkage, unequal sinkage and the lining stress of numerical analysis are within permission and the damage degree is appearing with the fact that the degree it will can disregard it is slight. But it enforces necessary Pre-grouting in order to minimize an actual tunnel face conduct and when the tunnel is excavated it is judged with the fact that necessary to minimize the outflow possibility.

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콘크리트의 누설성에 미치는 영향 요인에 관한 실험적 연구 (Experimental Study for the Factors Influenced on the Permeability of Concrete)

  • 김진근;이성태;양은익;김민욱;이성규;최강룡
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1998년도 봄 학술발표회논문집(II)
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    • pp.725-730
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    • 1998
  • In the nuclear power plant, steel or polymer liner plates are adopted to prohibit inner concrete surface contacting with gas or liquid materials. If there is an accident, the plate will be damaged, and concrete shall have final responsibility to safety requirements. In this paper, an experimental research was carried out to investigate the effects of construction joint and wet and loading condition on the permeability of concrete. The test results showed that leakage rate is decreased much more at the following cases than the others : (a)wet condition, (b)without a construction joint case, and (c)case subjected to external loads. It was noted that more reinforcement is required at the latter case.

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수평보강재로 보강된 터널 막장의 거동 (Behavior of Tunnel Face Reinforced with Horizontal Pipes)

  • 유충식;신현강
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 1999년도 가을 학술발표회 논문집
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    • pp.185-192
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    • 1999
  • This paper presents the results of a parametric study on the behavior of tunnel face reinforced with horizontal pipes. A three-dimensional finite element model was adopted in this study to capture the three-dimensional nature of tunnel face behavior under various boundary conditions. A parametric study was peformed on a wide range of boundary conditions with emphasis on the effect of reinforcing layouts on the deformation behavior of tunnel face. The results of analysis such as tunnel face deformation behavior under various conditions were thoroughly analyzed, and a database for the behavior of tunnel face under different reinforcing conditions was established for future development of a semi-empirical design/analysis method for the tunnel face reinforcing technique. The results indicated that there exits an optimum reinforcing layout for a given tunnel condition, which must be selected with due consideration of tunnel geometry and ground condition.

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점용접된 구조물의 좌굴하중해석 (Buckling Load Analysis of Spot-Welded Structures)

  • 이현철;심재준;안성찬;한근조
    • 한국항만학회지
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    • 제14권1호
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    • pp.87-95
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    • 2000
  • This stability of a plate structure is very crucial problem which results in wrinkle and buckling. In this study, the effect of the pattern of spot-welding points of the two rectangular plates on the compressive and shear buckling load is studied with respect to the thickness, aspect ratio of plates and number of welding spots. Buckling coefficient of the plate not welded was compared with that of two plates with various thickness to extract the effect of thickness. The effect of number of welding spots are studied in two directions, longitudinal and transverse directions. The conclusions obtained were that the reinforcement effect was maximized when the aspect ratio was close to 1.75 at compressive load condition and that the effect of number of welding spots in transverse direction was larger than that in longitudinal direction at shearing load condition.

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철근강화콘크리트에 대한 받음각이 없는 관통자의 수직관통거동 전산해석 (Numerical Simulations of the Normal Perforation Behavior by Penetrator without AOA into Steel Reinforced Concrete Targets)

  • 윤경재;유요한;김학준
    • 한국군사과학기술학회지
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    • 제16권3호
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    • pp.398-404
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    • 2013
  • The simulation of the ballistic trajectory of penetrator into the spaced multi-layer RC targets is very important to predict the hitting condition in subsequent target. Because of perturbation by lateral load of penetrator caused by asymmetric hitting position between penetrator and steel bar reinforcement, penetrator rotates and deviates from the straight path. Therefore, penetration capability of penetrator is decreased in the subsequent targets. This paper presents the result of the penetration of steel-bar-reinforced concrete target by using the explicit finite element code LS-DYNA. A series of computations is performed and compared to experimental data and the computed results are in good agreement with the experimental results over a wide range of velocities. And then we conduct the simulation according to various RC target hitting condition and impact velocities.

공공기관의 보상 현황과 개선방향 (The Present Condition and Future Directions of Public Organizations)

  • 오재인
    • 한국경영과학회지
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    • 제40권1호
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    • pp.129-138
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    • 2015
  • The problems associated with the excessive compensation of the public organizations in Korea have been presented not only by the press but also by the academic societies, including the management evaluation team of the public organizations, both in Korea and abroad. To analyze whether the compensation is excessive necessitates the empirical study on the present condition of the compensation system of the public organizations. Therefore, the purpose of this paper is to suggest the issues and the future directions of the compensation in the public organizations. The findings from the analysis of the data collected in this research include the expansion of the difference in compensation, the reinforcement of the job and performance-based compensation, the systematization of the model on the base compensation, and the differentiation of the compensation increase based on productivity.

800kV, 50kA 차단기의 전절연 검증을 위한 시험방법 검토 (Review about test method for the full-insulation verification of circuit breaker rated on 800kV, 50kA)

  • 박승재;서윤택;윤학동;김용식;김맹현;고희석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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    • pp.569-571
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    • 2005
  • In case of dead-tank circuit breaker with the earthed enclosure, the dielectric performance for phase to ground should be verified under the hot-gas condition produced by the current interruption. This test condition is required in breaking test duties with the rated short-circuit current and rated voltage. And, KERI has completed the reinforcement of the synthetic testing facilities and these facilities have the testing capacity which enables the full-pole testing for 800kV circuit breaker by adopting the series voltage injection method. So, this paper introduced the test circuit and procedures about the full-pole and the multi-part testing method which was devised to estimate the full -insulation of phase-to-ground for the multi-pole and dead-tank circuit breaker.

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전단연결부 형상에 따른 분절부재의 전단내하력에 대한 실험적 연구 (An experimental study for shear loading capacity of segmental members depending on various types of shear connector)

  • 한만엽;강태헌;신재우;진경석;강상훈
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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    • pp.158-161
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    • 2006
  • The numerical analysis and the experiment was performed to investigate the influences of shear connector on shear resistance capability. The numerical analysis's results should that the H/B ratio of shear key is more effective than angle of shear key against shear strength and shear behavior, and it is more desirable to use a half of the H/B ratio of shear key. The specimen was made with same condition as AASHTO recommended. There model tests were performed under various form of shear key, number, arrangement reinforcement and condition using epoxy. As a result of the experiment, there is little difference(or there is no difference) between the case of using epoxy on shear connector and the unused case.

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손상 방지용 보강재의 용접부 피로특성 (Fatigue Properties of reinforcement plate for damage prevention)

  • 김현수;박윤기;황주환;윤중근
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2005년도 추계학술발표대회 개요집
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    • pp.91-93
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    • 2005
  • The purpose of this study is to evaluate effects of stiffener configuration welded to the plate on the fatigue strength. Nominal stress and hot spot stress for the stiffened plate under pure bending condition were evaluated using FEA and experiment and fatigue test for each specimen was performed. For S and SD type, the fatigue strength increase with a decrease in the nominal stress and hot spot stress. D type with doubler plate was found to have the lowest value of nominal and hot spot stress for a given condition. However its fatigue strength was smaller than the others.

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Structural Behavior of a RC Bridge Slab Retrofitted with Carbon Fiber Sheet under Large Repeated Load

  • Park, Hae-Geun
    • KCI Concrete Journal
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    • 제14권2호
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    • pp.61-68
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    • 2002
  • An experimental investigation on the flexural fatigue behavior of a RC bridge slab retrofitted with Carbon Fiber Sheet (CFS) is presented. The test slab was almost identical to the slab of a highway viaduct in terms of the amount of reinforcement, quality of concrete and thickness of the slab, which was 18cm. Repeated load corresponding to 3.0, 4.5 or 6.0 times of the design load was applied to the test slab. Normal type and high-elastic modulus type of CFS were used for strengthening. The test slabs were loaded in dry or wet condition. Two different types of an-choring system were adapted. Some of the test slabs were damaged by the repeated load and retrofitted by CFS, then loaded again to see the improvement of the fatigue life. Infrared Thermography was also performed to investigate the debonding condition of CFS. From the test results, Carbon Fiber Sheet can be applied to the RC bridge slabs as a feasible retrofitting material.

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