Bridges are essential infrastructures in the social and economic activity and for effective delivery of the post-earthquake emergency aid and rescue. This thesis focuses on the resilience assessment of bridges through numerical simulation to estimate the earthquake damage under different earthquake intensities measures and to recover. To this aim, a case study will be selected, in particular the "Bormida of Millesimo" Viaduct was analyzed, and its detailed numerical model was taken into account. Considering the estimated damage level, the functionality will be assessed and a retrofitting of the structure was proposed. The analyses after retrofitting were performed and the final results were showed, checking the effectiveness of the improvement.