Evaluation of the design seismic demands in regular and irregular bridges with fixed and free abutment conditions designed using the AASHTO provisions

The seismic ductility demands obtained for the design of ۳۸ regular and irregular fourspan RC bridges based on AASHTO provisions are evaluated in this research. The irregularity in the bridges were due to different column heights, as well as, different span lengths. The bridges were designed for different abutment conditions including fixed and free transverse movements at the abutments. The effects of the abutment condition on the design seismic ductility demands of bridges with different configurations were studied. The maximum seismic ductility demands predicted for the columns with different heights were evaluated and recommendations were made for the use of appropriate abutment conditions for different bridge configurations and the bridges with a critical seismic behavior were identified

Keywords:

Seismic Design , Displacement Based Method , Irregular Bridge , Ductility Demand