ABSTRACT
The main objective of this study is to present an efficient method for developing seismic fragility curves for regular and irregular reinforced concrete (RC) bridges based on the capacity spectrum assessment, i.e., FRACAS method. Accordingly, 3D models of unbalanced, skewed, and curved irregular bridges were considered, taking into account uncertainties related to geometry, material as well as seismic excitation characteristics. In the presented methodology, the FRACAS method, which was initially developed for buildings, was appropriately modified to become suitable for the 3D analysis of the examined bridges, reducing also the demand error compared to -computationally demanding- non-linear time-history analysis (NTHA) approach. For this purpose, the fragility curves obtained from the proposed 3D FRACAS were compared with those obtained via NTHA. Results illustrate that the 3D FRACAS approach can be efficiently used for developing the fragility curves for regular and irregular bridges in a computationally efficient and accurate manner.
