Pushover Analysis of Inelastic Seismic Behavior of Greveniotikos Bridge

Abstract

Nonlinear pushover analysis is a powerful tool for evaluating the inelastic seismic behavior of structures. The paper deals with the nonlinear analysis process followed during the independent design check of the Greveniotikos Bridge in Greece. The nonlinear response of the bridge was investigated from the first pier hinging to the inelastic equilibrium condition during the design-level earthquake and then up to the ultimate limit state. The effects on the seismic demand of period lengthening and damping increase produced by structural deterioration were evaluated. Onset and progression of plastic hinges were determined along with the pier stiffness distribution and the force reduction factors to be used in spectral analysis. The nonlinear loading conditions of plastic hinges were analyzed to assess their rotation capacity and shear strength. Finally, the safety factor from progressive collapse condition was evaluated. The parametric approach followed in this work permitted evaluation of the effects of several parameters on the inelastic structure response, thus enhancing confidence with result evaluation.