Assessment of Continuous Span Bridges through Nonlinear Static Procedures

Nonlinear static procedures constitute an important tool in design office application of performance-based earthquake engineering concepts, and for this reason, they have been extensively developed and promoted in the last decade or so. However, these efforts focused predominantly on the assessment of buildings, rather than bridges, and hence there is currently a need to verify the validity in the application of such pushover-based methods for the assessment of bridges or viaducts. In this work, therefore, by considering a wide set of bridge configurations subjected to equally varying seismic input intensity levels, four commonly employed nonlinear static procedures (CSM, N2, MPA, ACSM) are scrutinized and compared, with a view to establish their adequacy for the seismic assessment of existing continuous span bridges. Results seem to indicate that all methods are able to predict displacement response with good accuracy, while force estimation, on the other hand, is reasonably attained only by those approaches where higher modes effects are explicitly accounted for.