Bull Earthquake Eng (2011) 9:1463–1498 DOI 10.1007/s10518-011-9260-8 ORIGINAL RESEARCH PAPER A performance-based adaptive methodology for the seismic evaluation of multi-span simply supported deck bridges Donatello Cardone · Giuseppe Perrone · Salvatore Sofia Received: 18 December 2009 / Accepted: 22 March 2011 / Published online: 9 April 2011 © Springer Science+Business Media B.V. 2011 Abstract A performance-based adaptive methodology for the seismic assessment of high- way bridges is proposed. The proposed methodology is based on an Inverse (I), Adaptive (A) application of the Capacity Spectrum Method (CSM), with the capacity curve of the bridge derived through a Displacement-based Adaptive Pushover (DAP) analysis. For this reason, the acronym IACSM is used to identify the proposed methodology. A number of Performance Levels (PLs), for which the seismic vulnerability and seismic risk of the bridge shall be evaluated, are identified. Each PL is associated to a number of Damage States (DSs) of the critical members of the bridge (piers, abutments, joints and bearing devices). The IACSM provides the earthquake intensity level (PGA) corresponding to the attainment of the selected DSs, using over-damped elastic response spectra as demand curves. The seismic vulnerability of the bridge is described by means of fragility curves, derived based on the PGA values associated to each DS. The seismic risk of the bridge is evaluated as convolution integral of the product between the fragility curves and the seismic hazard curve of the bridge site. In this paper, the key aspects and basic assumptions of the proposed methodology are presented first. The IACSM is then applied to nine existing simply supported deck bridges, characterized by different types of piers and bearing devices. Finally, the IACSM predictions are compared with the results of nonlinear response time-history analysis, carried out using a set of seven ground motions scaled to the expected PGA values. Keywords Bridges · Seismic evaluation · Damage states · Adaptive pushover analysis · Capacity spectrum method · Nonlinear response time-history analysis 1 Introduction Recent earthquakes have repeatedly demonstrated the seismic vulnerability of existing bridges, due to their design based on gravity loads only or inadequate levels of lateral forces D. Cardone (B ) · G. Perrone · S. Sofia DiSGG—University of Basilicata, Potenza, Italy e-mail: donatello.cardone@unibas.it 123