عنوان مقاله [English]
Vulnerability assessment and seismic retrofit of bridges as lifelines are of great importance. In recent years, performance-based procedures in bridges are taken into consideration by researchers. In this paper after evaluation of proposed methods for seismic performance assessment of bridges, a laboratory model of box-shaped steel bridge piers was analyzed for verification and results were compared with a tested model’s data. Then based on the properties of a real bridge, several bridges’ models were designed for parametric studies. The mentioned bridge is continuous and consists of steel moment frames in a longitudinal direction. Further, after evaluating performance levels of the bridges, obtained results were compared with damage indices and the difference between structural specifications and mentioned indices were indicated. The nonlinear static analysis procedure was utilized to analyze the models. Energy, effective stiffness and Park-Ang damage indices were employed to evaluate damage. Independence of indices from geometric changes of structures, the high adaptation of Park- Ang index with energy index due to use of energy as a common concept and more accurate results of energy damage index in each performance level were some of the results.