Simplified model for the seismic analysis of highway bridges

Abstract

A seismic vulnerability evaluation method based on structural analysis for RC highway bridges with simple pier bents is proposed in the paper. The proposed method is based on the hypothesis of the flexible pier-rigid deck behaviour of the structure subjected to transversal seismic loads. A flexible pier-rigid deck simplified model was therefore developed. This model has been chosen after verifying the correlation between the responses of the proposed model and of the real structure in its first few vibration frequencies. The study of the damage produced by the earthquake load is centered on the piers of the bridge, while the dynamic study of the deck can be performed after the structural analysis of the piers in an uncoupled way. The maximum damage of the piers under seismic actions is the principal aim of the proposed structural evaluation methodology. A local damage index is used for this purpose, which describes the state of the material at each point of the structure and is based on a constitutive damage law. The proposed model permits a simple, reliable and efficient structural analysis.