Development of Fragility Curves for Multi-Span RC Bridges using Generalized Pushover Analysis

Over the past few decades, fragility curves became a powerful tool for the seismic vulnerability assessment of structures. There are several available analytical procedures for calculating fragility curves, using both static and dynamic nonlinear analyses. In this study, a nonlinear static method, based on Generalized Pushover Analysis (GPA), is implemented for the development of analytical fragility curves of reinforced concrete (RC) bridges. The relative accuracy of the GPA algorithm, when applied to a large number of existing bridges, is evaluated through the comparison with the results from Nonlinear Time History Analysis (NTHA). Results indicate that GPA provides a good estimation of the fragility curves with respect to NTHA. The added computational demand of the GPA algorithm in terms of the number of analyses pays off in terms of accuracy while keeping the simplicity of a non-adaptive conventional pushover algorithm, which is desirable in engineering practice.