Displacement limits and performance displacement profiles in support of direct displacement-based seismic assessment of bridges

Displacement limits and performance displacement profiles (PDPs) for the direct displacement-based assessment of existing bridges are proposed. The PDPs are defined as the bridge inelastic deformed shapes associated with the attainment of selected damage states in some critical elements of the bridge. In the paper, displacement limits are provided for piers, abutments, joints, bearing devices and shear keys. Moreover, different approaches for the definition of the PDP are examined, including adaptive pushover analysis, effective modal analysis, and rational analysis of simplified bridge models. In the paper, the key aspects and modeling assumptions of the proposed direct displacement-based assessment procedure are presented first. This is followed by some examples of application to typical Italian highway bridge configurations, differing in pier layout, deck type, and pier-deck connections.