Influence of The Abutment Modeling on the Fragility Curves of the Three Span Concrete Continous Bridge

Fragility curves demonstrate the probability of exceedance of performance measure from limit state at given seismic intensity. Responses obtained from bridges during their nonlinear time history analysis are used to draw such curves. Most bridges in Iran have not been exposed to high intensity earthquakes until now and correspondingdamage data is not sufficient. Different performance measures could be conceived of in offering fragility curve for bridges among which are responses at piers and responses at bearings. From these responses, curvature ductility and on the concrete piers and abutments deformation are factors chosen for generating fragility curves. In this study, Modeling of the bridge using OpenSees done three-dimensionaly. Soil-structure-interaction effects are included in the model. Tow type model including real and roller be used on the abutment. The comparison of fragility curves resulted from Bayesian method and based on behavioral curve shows maximum difference of 20 percent. Also, development of fragility curves related to roller abutment show that curves at the limits of demand mean in probability function, are more vulnerable rather than real model in the high seismic intensities. Results represent probabilities of damage in different conditions of seismic intensity.

Keywords:

Damage , Seismic Intensity , Fragility Curves , Nonlinear Finite Elements Analysis