A RAPID SEISMIC SCREENING-PROCEDURE FOR EXISTING BRIDGES IN CANADA

The seismic behaviour of existing bridges in Canada remains an importa nt problem, since most of these structures have been built before mode rn seismic provisions. Recent earthquakes around the world have demons trated that such older structures can behave poorly under even a moder ate ground excitation. The cost for a systematic evaluation and retrof it of bridges in Canada would be prohibitive and therefore such an ope ration is impractical. As an alternative, this paper presents a rapid seismic screening procedure for existing bridges in Canada. The main g oal of the procedure is to allow owners to prioritize their structures for further detailed seismic evaluations. The procedure can also be u sed to provide data for a postearthquake inspection of bridges located in the epicentral region. Special care has been taken to make the met hod rapid and simple. Technical personnel without any specific knowled ge of seismic design should correctly perform the screening evaluation . The procedure can also be easily incorporated in an existing bridge inspection program. The paper describes the various parameters of the screening procedure. Screening examples of bridges in the Montreal met ropolitan area are also presented.