• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.547-552
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• 1998

The small-scale models have been utilized for the prediction of inelastic behavior of reinforced concrete structures for a long time. The parameters that affect the similitude between the model and the prototype are various. Among them, the effect of bond between the model reinforcement and the model concrete is one of the most important factors. The study reported herein is addressed to verifying this similitude in bond behavior. Another topic is the similitude in shear. The selected scales are 1/1, 1/5, 1/10 and 1/12. Two prototype specimens and three models were tested in addition to the associated material tests. The test results are compared from the viewpoint of similitude.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 가을 학술발표회 논문집
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• pp.187-192
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• 1995

Four types of experiments were performed to check the similitude of member behavior between prototype and 1/10 scale models:(1) Test of slender columns with P- effect, (2)Test of short columns with and without confinement steel, (3)Test of simple beams without stirrups, and (4)T-beam test. Based on the results of experiments, the conclusions were made as follows : (1) The P- effect of slender columns can be almost exactly represented by 1/10 acale model. (2)The effect of confinement on short columns by the hoop steel can also roughly simulated by 1/10 scale model. (3)The failure modes of simple beams models were the yielding of tension steel followed by large diagonal tension cracking+compressive concrete failure. (4)The behaviors of prototype and 1/10 scale model in T-beams appear very similar.

• 한국지진공학회논문집
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• 제21권2호
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• pp.87-93
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• 2017

Many studies are conducted in several fields for fragility analysis of structures or elements which is a probabilistic seismic safety analysis in consideration with uncertainty of seismic loading. It is hard to directly conduct fragility analysis for an infrastructure with social importance due to its size. Therefore, a fragility analysis for an infrastructure mainly conducted in element level or conducted with scaled model built in accordance with similarity law. In this article, fragility analysis for prototype and scaled model of reinforced concrete column was conducted with numerical models which had been updated by the results of shaking table test and pseudo dynamic test. As a result, response stress from the numerical analysis result of prototype model was higher than that from scaled model due to different stiffness ratios between steel and concrete. However, the probability of failure for scaled model was higher than that for prototype model because failure criteria for scaled model was down due to similarity law. Also it was evaluated that probability of failure by using log normal standard deviation of response stresses by spectrum matched accelerograms was more reliable than probability of failure by using existing coefficient of variation normally used.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2006년도 학술발표회 논문집
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• pp.545-552
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• 2006

Small-scale models have been frequently used for seismic performance tests because of limited testing facilities and economic reasons. However, there are not also enough studies on similitude law for analogizing prototype structures accurately with small-scale models, although conventional similitude law based on geometry similitude is not well consistent in their inelastic seismic behaviors. When fabricating prototype and small-scale model of reinforced concrete structures by using the same material, added mass is demanded from a volumetric change and scale factor could be limited due to aggregate size. Therefore, it is desirable to use different materials for small-scale model. In our recent study, a modified similitude law was derived depending on geometric scale factor, equivalent modulus ratio and ultimate strain ratio. And quasi-static and pseudo-dynamic tests on the specimens are carried out using constant and variable modulus ratios, and correlation between prototype and small-scale model is investigated based on their test results. In this study, tests on scaled model of different concrete compressive strength aye carried out. In shaking table tests, added mass can not be varied. Thus, constant added mass on expected maximum displacement was applied and the validity was verified in shaking table tests. And shaking table tests on non-artificial mass model is carried out to settle a limitation of acceleration and the validity was verified in shanking table tests.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 추계 학술논문 발표대회
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• pp.135-136
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• 2011

A standard of estimation is used as a basis for estimating the predetermined amount of public construction. However, they raise several points of reasonable labor to be presented to a standard of estimation. For this reason, it is difficult to make a reasonable and efficient estimation of the costs, and this situation presents an urgent need for an accurate way of making such a calculation.This study analyzed the productivity of reinforced concrete work by the CYCLONE model, and the estimated optimal labor through sensitivity analysis, and presented the model on the number of optimal labor through sensitivity analysis.

• Computers and Concrete
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• 제21권4호
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• pp.385-397
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• 2018

This study is focused on the investigation for similitude the requirements between prototype and scaled models to determine the structural behavior of concrete load bearing systems. The scaling concept has been utilized in many engineering branches, has been assisted to engineers and scientists for obtain the behavior of the prototype by using scaled model. The scaling can be done for two purposes, either scaling up or scaling down depending upon the application. Because, scaled down models are the experimentation on scaled models is cheaper than huge structures. These models also provide facilities for experimental work. Similarity relationships between systems are created either by field equations of the system or by dimensional analysis. Within this study, similarity relationships were obtained by both methods. The similarity relations obtained are applied to different load bearing systems and it is determined that the similarity relation is a general expression. In this study, as an example, column, frame, cantilever beam and simple beam are chosen and 1/2, 1/5 and 1/10 scales are applied. The results are compared with the analytical results which are obtained by creating of the finite element models with SAP2000 software of different scaled load bearing systems. The analysis results of all systems are examined and it is determined that the scale factors are constant depending on the scale types for different load bearing systems.

• 콘크리트학회논문집
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• 제22권6호
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• pp.805-816
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• 2010

축소모델의 지진모의실험을 위해서는 실물 실험체의 구조거동을 축소모델 실험체가 잘 모사하는지 상사성 확인이 필수적이다. 본 논문에서는 2층 RC 벽식구조 실험체의 반복 횡가력 실험을 통해 강도, 연성과 같은 전체거동과 휨, 전단, 들뜸과 같은 국부거동의 결과를 나타내었다. 인방보의 유무에 따른 3 : 5 실물 실험체와 1 : 7 축소모델 실험체를 비교 분석 하였으며, 1 : 7 축소모델 실험체가 실물 실험체의 전체거동과 국부거동에 대해서 대체로 잘 모사하고 있음을 확인하였다.

• 한국해양공학회지
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• 제14권2호
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• pp.84-88
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• 2000

The main objectives of this study are to compare the obtained mechanical characteristics of reduced-scale model materials with those of the prototype and to provide the information on the best selection of materials. Manufacturing techniques on the micro-concrete and reduced reinforcement are introduced. The test results of these materials are shown to be satisfactory with regard to the similitude requirement. The simple beam tests were performed to verify similitude in the bond behavior between micro-concrete and reduced reinforcement. Those results also prove that these manufacturing and experimental techniques are useful and reliable for reduced-scale model tests.

• 한국지진공학회논문집
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• 제8권5호통권39호
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• pp.35-43
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• 2004

대형 구조물의 지진응답을 실험적으로 연구할 경우, 실험장비의 용량과 실험모형의 크기 제약으로 인하여 축소모형이 일반적으로 적용되고 있다. 그러나 구조물의 지진응답은 비탄성 거동을 나타내기 때문에 거동예측이 복잡함에도 불구하고, 축소모형의 지진실험 결과로부터 원형구조물의 지진응답을 유추하기 위한 상사법칙의 연구는 미비한 실정이다. 철근콘크리트 구조물의 축소모형 제작 시 상사율이 커지면 상대적으로 부가질량이 증가하며, 또한 굵은 골재 크기의 영향으로 원형구조물과 축소모형의 제작에 동일한 재료를 사용하지 않는 것이 바람직하다. 따라서 동일한 재료를 사용하지 않을 경우, 상사법칙은 기하학적인 상사율과 재료적인 등가탄성계수비에 의존하게 된다. 본 연구에서는 원형구조물과 축소모형에 각각 적용되는 normal-concrete와 micro-concrete의 재료 비선형성을 파악하기 위해 압축강도시험을 수행하여, 재료의 거동구간을 극한 변형률을 기준으로 등가의 다단계로 나누어 등가탄성계수비를 적용시킴으로써 지진손상의 정도를 고려할 수 있는 equivalent multi-phase similitude law를 유도하였다. 유도된 상사법칙을 고려한 유사동적실험 알고리즘을 구성하였으며, 실험적인 검증을 위하여 철근콘크리트 column에 대하여 원형구조물과 1/5축소모형을 재료시험에서 정의한 등가탄성계수비를 고려하여 설계, 제작하였다. 검증실험에서는 constant modulus ratio와 variable modulus ratio를 적용하여 준정적실험과 유사동적실험을 수행한 결과, equivalent multi-phase similitude law를 고려한 유사동적실험 알고리즘에 의한 축소모형의 응답결과가 원형구조물의 거동을 비교적 정확히 재현함을 확인하였다.

• Structural Engineering and Mechanics
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• 제51권4호
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• pp.663-683
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• 2014

In order to study the dynamic failure mechanism and aseismic measure for high concrete gravity dam under earthquake, the comparative models experiment on the shaking table was conducted to investigate the dynamic damage response of concrete gravity dam with and without the presence of reinforcement and evaluate the effectiveness of the strengthening measure. A new model concrete was proposed and applied for maintaining similitude with the prototype. A kind of extra fine wires as a substitute for rebar was embedded in four-points bending specimens of the model concrete to make of reinforced model concrete. The simulation of reinforcement concrete of the weak zones of high dam by the reinforced model concrete meets the similitude requirements. A tank filled with water is mounted at the upstream of the dam models to simulate the reservoir. The Peak Ground Acceleration (PGA) that induces the first tensile crack at the head of dam is applied as the basic index for estimating the overload capacity of high concrete dams. For the two model dams with and without strengthening tested, vulnerable parts of them are the necks near the crests. The results also indicate that the reinforcement is beneficial for improving the seismic-resistant capacity of the gravity dam.