콘크리트 사장교의 장기거동 해석을 위한 예측 모델의 비교

Abstract

Recently, for the stability of structures and the economy, the construction of cable-stayed bridges using the composit girder and the prestressed concrete girder tends to increase. In the characteristics of its concrete material, the cable-stayed bridge is greatly influenced by the long-term behavior of concrete like creep and drying shrinkage. To predict the long-term behavior of concrete, ACI Committee 209(hereinafter, ACI model), CEB-FIP (1990), and B3 models are generally used. In this study, for the correct use of these models, the features of each model were analyzed. The B3 model with many influential factors has a merit that it can most appropriately reflect the behavior according to time duration but it seems too complex to use. Moreover, to find out the influence of diverse influence factors on the long-term behavior prediction models, the parametric analyses were made. When ACI model and CEB-FIP model were compared in each stage of construction, ACI model was estimated more conservative than CEB-FIP model except under pylon. And, as a result of variables analysis on the relative humidity and the strength, it was concluded that the yearly average relative humidity of each location should be considered in its design, and that the pylon where the stresses are concentrated and the places such as the rigid connections of decks where the change of stress is great according to the strength increase should also be given special attention.