Open issues in the seismic design and assessment of bridges

The paper presents an overview of recent research on the seismic as- sessment/retrofit and design of bridges, focussing on some of the aspects which are still not adequately covered in the codes. These are: The level of protection to be provided when upgrading an existing bridge, and in particular whether this should be differentiated between new designs and retrofit of existing bridges; The appropriate methods of analysis and modelling, with emphasis on the scope of nonlinear static methods and to the problems related to the selection of the input for dynamic analysis; Soil-foundation-structure interaction and non uniform sup- port input, representing two controversial issues that may be mature for an inclu- sion in routine bridge analysis.