ABSTRACT
ABSTRACT: The Incremental Response Spectrum Analysis (IRSA) procedure is introduced as an advanced multi-mode pushover analysis tool for the performance-based seismic assessment and design of buildings and bridges (Aydınog˘lu 2003). The practical version of the procedure (Aydınoglu 2004) works directly with smoothed elastic response spectrum and makes use of the well-known equal displacement rule to scale modal displacement increments at each piecewise linear step, in which the traditional linear Response Spectrum Analysis (RSA) is implemented. Being a general analysis tool, IRSA is completely independent of the type of structure, as in its linear counterpart RSA. In this respect, IRSA is readily applicable to any type of bridge. In the present contribution, IRSA is applied to few types of highway bridges and its performance is checked against the results of the corresponding nonlinear response history analysis (NRHA) performed. It is shown that IRSA is capable of estimating bridge nonlinear demands with an acceptable accuracy for practical purposes.
