SEISMIC RETROFITTING TECHNIQUES FOR BRIDGES - A STATE-OF-THE-ART REPORT

This paper presents a review of the various seismic retrofitting techn iques currently being carried out for bridge structures. After evaluat ing the performance of existing bridges in past earthquakes and their most common modes of failure, a systematic review of bridge retrofit i s discussed. It includes the retrofit of foundations, concrete columns , bent cap beams and beam-column joints, as well as steel bracing. The use of restrainers is discussed as well as the possible improvements to bearing supports. Examples of bridge retrofit practice in Californi a and British Columbia are presented.