Performance-based seismic design of unbonded precast post-tensioned concrete filled GFRP tube piers

This paper presents a seismic design procedure for self-centering precast post-tensioned bridge piers. The piers presented in this manuscript consisted of concrete filled fiber reinforced polymer (FRP) tubes. A large set of 84 piers with different design parameters were analyzed using finite element models. The backbone curve of each pier was developed and bilinearized. The idealized backbone curves were used to develop a set of empirical equations that were able to reproduce the bilinearized backbone curve of a given pier. Different performance criteria have been proposed for the system according to the intensity and the frequency of occurrence of a seismic event. The developed empirical equations were arranged in a design procedure to achieve a given performance level at a specific seismic zone.