A methodology for Determining the Seismic Vulnerability of Old Concrete Highway Bridges by Using Fragility Curves

摘要: Past earthquakes have demonstrated that old RC bridges may be seismically vulnerable. Bridge responses during the last decades illustrated necessity of seismic assessment especially those which were designed with codes. In this research an existing concrete bridge representative most common in highway system Iran are studied. Push over and nonlinear time history analyses using refined 3-D structural models performed for each sample. systems identified quantified to establish a set earthquake-site-bridge samples. The superstructure was assumed remain elastic behavior piers modeled by assigning plastic hinges columns. soil flexibility considered spring elements. Displacement ductility peak ground acceleration (PGA) selected as performance indicator intensity measure, respectively. Ten records from past selected. They scaled applied incrementally model evaluate bridge. Furthermore, damage states defined probabilistic characteristics capacity corresponding state established. Then, conditional probabilities specific demand exceed computed results displayed fragility curves.