RÉSUMÉ La majorité des ouvrages conçus avant 1980 ne répondent pas aux normes sismiques actuelles puisqu’à l’époque les exigences à ce niveau étaient moins élevées qu’aujourd’hui et surtout certaines considérations usuelles relatives au design de l’époque ont démontré leurs incapacités à résister aux charges sismiques. Depuis, les connaissances dans le domaine et les avancées
technologiques des outils de calcul ont permis de comprendre davantage la réponse structurale à ces phénomènes rares pouvant néanmoins causer des dommages structuraux importants.----------ABSTRACT Most of bridges built before the ’80s do not respect current code requirements. At that time, seismic elated specifications were less severe than today’s and, mostly, some design methods used then are now proved to be wrong against loads due to earthquakes which can cause many considerable
damages on structures. Many developments in seismic design from then were made, and they have helped to understand the seismic response better. Technology progress has also contributed to improving calculus methods. These bridges having major seismic design disabilities need some
reinforcement to have a congruent design mostly on piers which are the structural element where plastic deformations are permitted to reduce seismic forces and hence, protect other structuralelements
