Hysteretic Model Development and Seismic Response of Unbonded Post-Tensioned Precast CFT Segmental Bridge Columns

摘要

The aim of this research was to investigate experimentally the durability of the unbonded posttensioned,precast concrete-filled tube (CFT) segmental bridge columns subjected twice to cyclicloading. In addition, a stiffness degrading flag shaped (SDFS) model was developed based on selfcenteringcapability and stiffness degradation of the columns. The SDFS model overcomes thedeficiency of prediction using a flag shaped (FS) mode, which self-centers with constant stiffness.The experimental and analytical results show that (1) the deformation of the column in two tests issimilar but energy dissipation of that is significantly reduced in the second test, and (2) the SDFSmodel can predict the cyclic response of the column better than that using the FS model. Aparametric study, performed on systems subjected to earthquake records, shows that increase ofdisplacement ductility is significant for structures with low period and medium yield strength ratio.