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Abstract
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This study aims to determine probabilistic seismic demand-based optimal intensity
measures (IMs) for seismic fragility evaluation of corrosion-damaged reinforced concrete
(RC) bridge piers. Toward this goal, a methodology is presented to select optimal IMs
based on four criteria: efficiency, practicality, proficiency and sufficiency. Thirty-eight
intensity measures in five categories of (i) acceleration-related, (ii) velocity-related, (iii)
displacement-related, (iv) hybrid, and (v) general IMs are studied. The methodology is
demonstrated in a case study of an RC bridge with various corrosion levels. The finite
element model of a reference bridge pier is developed and verified by experimental results.
Incremental dynamic analyses (IDAs) are carried out on the studied corrosion-damaged
bridge piers using 22 ground motion records selected employing the conditional mean
spectrum (CMS) methodology. The outcomes of IDAs are then used to develop linear
probabilistic seismic demand models (PSDMs) for each bridge pier with varying corrosion
damage. The obtained results show the high sensitivity of optimal IMs on the corrosion
level of RC bridge piers. For instance, while the optimal IMs for the pristine bridge pier
are sustained maximum acceleration (SMA) and effective peak acceleration (EPA), for the
severely corroded pier peak ground acceleration (PGA) and acceleration level containing
up to 95% of the Arias intensity (A95) are the most optimal IMs
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