Despite recent progress by the structural engineering profession in addressing bridge seismic risks, several areas exist where improvements in bridge evaluation and retrofit practices are needed. This report reviews the common seismic deficiencies of bridges, procedures and criteria for the seismic evaluation of bridges, and the engineering techniques which have been used, up to 1996, for retrofitting bridge seismic deficiencies. Information on seismic deficiencies, retrofit techniques, and related research has been summarised in tabular form.
The review indicates several areas where effective retrofit techniques have been established, and other areas where improved procedures or further research are needed. Seismic upgrade measures proposed for Thorndon bridge, Wellington City, New Zealand, including an innovative retrofit of superstructure linkages, illustrate the benefits of a capacity-design approach to seismic evaluation and retrofitting.
Keywords: Bridges, capacity design, earthquakes, New Zealand, retrofitting, seismic evaluation, structural engineering, Thorndon bridge