Regularity Criteria for RC and PRCMultispan Continuous Bridges

A parametric study was carried out to provide criteria for structural regularity on reinforced concrete (RC) or precast rein- forced concrete (PRC) multispan continuous bridges, assessing whether an equivalent single degree-of-freedom (ESDOF) system represents a multiple degree-of-freedom (MDOF) system correctly. The ESDOF system, determined by means of a nonlinear static analysis, is compared, in terms of displacements, with the original MDOF through a nonlinear dynamic analysis. To this end, a sample of 32 bridges was considered, taking into account the effect of the stiffness ratio between various piers and between piers and decks. Together with the the evaluation of the reliability of the regularity indexes found in the literature, a comparative analysis was carried out. The results showed that the simplified system is representative of the bridge global behavior when the deck is stiff enough to control pier displacements and deformations and when the pier distribution is symmetric.