• 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.

• 한국도로학회논문집
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• 제19권6호
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• pp.67-74
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• 2017

PURPOSES : In this study, a three-dimensional nonlinear finite element analysis (FEA) model for airport concrete pavement was developed using the commercial program ABAQUS. Users can select an analysis method and set the range of input parameters to reflect actual conditions such as environmental loading. METHODS : The geometrical shape of the FEA model was chosen by considering the concrete pavement located in the third-stage construction site of Incheon International Airport. Incompatible eight-node elements were used for the FEA model. Laboratory test results for the concrete specimens fabricated at the construction site were used as material properties of the concrete slab. The material properties of the cement-treated base suggested by the Federal Aviation Administration(FAA) manual were used as those of the lean concrete subbase. In addition, preceding studies and pavement evaluation reports of Incheon International Airport were referred for the material properties of asphalt base and subgrade. The kinetic friction coefficient between the concrete slab and asphalt base acquired from a preceding study was used for the friction coefficient between the layers. A nonlinear temperature gradient according to slab depth was used as an input parameter of environmental loading, and a quasistatic method was used to analyze traffic loading. The average load transfer efficiency obtained from an Heavy falling Weight Deflectomete(HWD) test was converted to a spring constant between adjacent slabs to be used as an input parameter. The reliability of the FEA model developed in this study was verified by comparing its analysis results to those of the FEAFAA model. RESULTS : A series of analyses were performed for environmental loading, traffic loading, and combined loading by using both the model developed in this study and the FEAFAA model under the same conditions. The stresses of the concrete slab obtained by both analysis models were almost the same. An HWD test was simulated and analyzed using the FEA model developed in this study. As a result, the actual deflections at the center, mid-edge, and corner of the slab caused by the HWD loading were similar to those obtained by the analysis. CONCLUSIONS : The FEA model developed in this study was judged to be utilized sufficiently in the prediction of behavior of airport concrete pavement.