• Journal of Acupuncture Research
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• 제15권2호
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• pp.211-225
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• 1998

It is very important to understand objectively the Qi variation induced by the reinforcing-reducing manipulation method in the therapy of acupuncture. The Qi variation in the meridian treated by O-Haeng Reinforcing-Reducing Manipulation Acupuncture Method and the recovery of Five Phase deviation were measured by choosing complex acupoints. By using O-Haeng Reinforcing-Reducing Manipulation Acupuncture Method, we increased or decreased the Qi of the phase which caused the unbalance state. We observed whether the Qi of the treated meridian can be increased or not and if the state of unbaIance can be recovered. To achieve the effect of reinforcing-reducing, we need a correct choice of treating method and a selection of a proper meridian in advance. We discovered that the effects of reinforcing-reducing by each manipulation method could be superposed each other, when two counteracting O-Haeng Reinforcing-Reducing Manipulation Acupuncture Method were treated at the left and the right side of human body. We found that the Qi variation of the traeted meridian, which was induced by O-Haeng Reinforcing-Reducing Manipulation Acupuncture Method, is lineary proportioned to the reduction of Five Phase deviation.

• 한국지반공학회논문집
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• 제16권6호
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• pp.87-95
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• 2000

A series of consolidated undrained triaxial compression testes were performed to increase field applications of soil admixtures mixed with short fiber. Kaolin clay and three types of fiber were selected and auto cutter was used to obtain reliable length of fibers. Remolded soil specimens were tested for obtaining the basic data to be applied to the reinforcement of soft clay, embankment or barrier and clay liner of wastes landfill etc. Conversion equations from weight to volume of clay mixed with short fiber are introduced and relationships between fiber content and fiber concentration are derived. It is found that reinforcing effect by aspect ratio and mixing ratio of short fiber decreases as confining pressure increases. The best efficient reinforcing effect is given at the aspect ratio of 80~120 and the fiber content of 1.2%~2.4% and the fiber diameter of 0.27mm.

• 한국지반환경공학회 논문집
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• 제9권6호
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• pp.5-12
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• 2008

본 연구에서는 타이어셀로 보강된 모래지반에 대한 평판재하시험을 유한요소법에 의해 모델링하였다. 타이어셀의 기능과 외양은 지오셀과 비슷하며 지오셀과 마찬가지로 토목구조물에서 지반보강 목적으로 사용할 수 있다. 해석결과는 모델링의 적절성을 평가하기 위해 현장 재하시험결과와 비교하였다. 두 결과의 비교로부터 유한요소해석에 의한 침하량은 극한지지력에서 실험결과와 유사한 값을 나타내었다. 모델링을 검증한 후 타이어셀의 보강깊이와 보강층 수의 변화에 대한 해석을 수행하였다. 보강효과는 보강깊이가 증가함에 따라 감소하였으며 이러한 경향은 기존의 시험결과와 유사하였다. 보강층수가 증가함에 따라 보강효과는 증가하였다. 그러나 2층 이상의 보강은 효과가 무시할 정도였다. 결론적으로 본 연구에서의 모델링 방법은 타이어셀을 사용한 지반구조물의 해석에 사용할 수 있을 것으로 생각된다.

• 한국지반환경공학회 논문집
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• 제13권9호
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• pp.83-89
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• 2012

지반 및 사면보강을 위해 국내에서 널리 사용되고 있는 공법으로 앵커, 쏘일네일 및 마이크로파일공법 등을 들 수 있다. 상기 공법들은 공통적으로 보강재를 설치한 후 그라우팅을 실시하는 공정을 포함한다. 압력재주입 그라우팅은 그라우트체의 직경확대와 그라우트체 주면의 응력 증가 및 불규칙한 표면을 조성함으로써 지지력을 증대시킬 수 있다. 그러나 국내에서는 시공장비와 적용실적의 부족 및 보강효과의 검증이 어려워 널리 적용되지 못하고 있는 실정이다. 이에 본 연구에서는 점성토 지반을 대상으로 그라우팅 방법에 따른 보강효과를 평가하기 위하여 실내 모형실험을 실시하였다. 실험결과, 인발력은 압력재주입 그라우팅 방식이 중력식 그라우팅에 비해 최소 1.22배에서 최대 2.61배까지 크게 발휘되는 것으로 나타났다.

• 한국지반신소재학회논문집
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• 제6권2호
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• pp.27-32
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• 2007

본 연구에서는 절토사면 공법선정시 고려해야 할 영향인자에 대한 가중치 결정과 사면보강공법 선호도를 AHP기법을 이용하여 분석하였다. 연구, 설계, 시공업에 종사하고 있는 전문가를 대상으로 분석한 결과 공법선택시 안정성 및 내구성, 환경성이 가장 중요한 영향인자로 조사되었으며, 안전율 증가법 위주로 분석된 사면보강공법 선호도 조사에서는 경제성과 유지관리 용이성, 안정성에서 가장 우수한 평가를 받은 옹벽공법과 절토공법이 가장 선호도가 높은 공법으로 분석되었다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 봄 학술발표회 논문집
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• pp.141-148
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• 1998

The chloride attack of the top mat of reinforcing bars is a major cause of deterioration of comcrete deck of plate girder bridges. This is caused by a current design method which requires a top mat of reinforcing bars to resist a negative bending moment in bridge decks. In recently, empirical evidence has indicated that the top transverse reinforcing bars can patially or fully be eliminated without jeopardizing the structural integrity of a deck. So, one of the most efficient way to increase durability of concrete deck of bridges is the development of new design method that reduce or eliminate the top mat reinforcing bars, mad it is possible by the exact analysis that considering the negative bending moment reducing effect which introduced by relative deflection of plate girders. In this study, we develop the new bridge deck analysis method that considered the effect of relative girder deflection by applying the principles of slope deflection method of frames, and that is fine tuned with results of finite element analysis. This new approach evaluate a bending moment in a deck based on the effect of relative girder deflection as well as the magnitude of wheel loads, the girder spacing and stiffness, deck stiffness and the span length

• 한국구조물진단유지관리공학회 논문집
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• 제3권3호
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• pp.269-277
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• 1999

The purpose of this study is to investigate the structural behavior of reinforced concrete columns rehabilitated with epoxy-bonded steel plates subjected to axial load. Eleven specimens were made to evaluate structural capacity of reinforced concrete columns rehabilitated with steel plates. This study considers the change of the internal force and the deformation of reinforced concrete column with reinforcing steel plates, and analyzes the effect of the improvement of strength and ductility. Based on the test results, this study brings the following conclusions. In case of the effect of reinforcement by the ratio of the same volume, the internal force for the test model, which the width of the reinforcing steel plate is small, is effectively higher. The smaller the width and the thickness of reinforcing steel plate, the more effective the effect of reinforcement is. For applying the theorical equation by Uzumeri, the maximum load and the coefficient of effective crossing reinforcement by the width and the thickness of steel plate reflected the properties of reinforcing steel plate.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.201-204
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• 2006

The shear resistance of RC beams is subject to the amount of shear-reinforcing bars ($p_w$) and yield strength ($f_{wy}$) as well as their interactive influence ($p_wf_{wy}$). Thus, it is reasonably expected that high-strength steel bars can greatly reduce the necessary amount of shear-reinforcing bars. On the other hand, although the bond strength is influenced by the amount of shear reinforcing bars, it is not affected by the yield strength. Thus, there is often an issue that bond failure occurs before shear failure depending on the arrangement of shear reinforcing bars. It is a common practice to set sub-ties for the transverse confinement of the main re-bars as a method to prevent the bond failure. However, it can also become a factor in decreased work efficiency due to the complexity of the construction. This study experimented with simultaneous use of high-strength transverse reinforcing bars ($f_{wy}=800MPa$) and U-shaped transverse reinforcing bars of regular strength ($f_{wy}=300MPa$) in an attempt to decrease the necessary quantity of shear reinforcing bars. The effect of this attempt was investigated through fundamental experimental research in terms of the improvement in shear resistance and bond strength as well as the ease of construction.

• 한국지반공학회논문집
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• 제20권5호
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• pp.59-66
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• 2004

본 연구에서는 토목섬유의 일종인 지오셀과 새로 고안된 폐타이어로 제작된 타이어셀, 타이어 매트의 지반보강 효과를 비교ㆍ고찰 하였다. 동일한 밀도, 복토두께 조건에서 실험용 토조내 평판재하시험을 수행하였다. 시험결과 타이어셀과 타이어측면의 조합 보강재가 가장 큰 지지력 증가와 침하량 감소를 나타내었다. 타이어셀과 같은 높이로 만든 지오셀의 보강효과는 타이어측면으로 만든 매트와 유사한 보강효과를 나타냈다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 가을 학술발표회 논문집
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• pp.319-324
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• 1994

Bond test was carried out to assess the effect of several variables on bond characteristics between reinforcing bar and concrete. Key variables are concrete compressive strength(low, medium high, and ultra-high), bar diameter(13mm and 22mm), and concrete cover(25mm; 1-inch, 38mm; 1.5-inch, and 51mm; 2-inch). Confining effect and bar spacing are not taken into account. Thirty-two specimens subjected to uniaxial tension were tested under hypothesis uniform bond stress distribution along the reinforcing bar embeded in concrete. Test results(ultimate bond stress) were compared with bond and development provisions of the ACI building Code(ACl 318-89) and local bond stress versus slip relationship diagram represented to show effect of the above variables.