Stress verifications of large concrete existing dams: comparison of two seismic Italian codes

A new version of the Italian design code for dams has been recently introduced, thus replacing after 30 years the previous code, which was still based on a permissible stress design philosophy. The new code follows a limit state approach, employs independent load and resistance factors and defines the earthquake actions in accordance with the new seismic classification of the Italian territory. It assigns at each point of the country its own specific uniform hazard spectrum. Focusing on the stress verifications of existing large concrete dams, in this paper some of the innovative aspects contained in the new dam code are discussed. Reference is made to two case studies concerning an arch-gravity and a buttressgravity dam, pointing out the main differences between the current and the previous version of the above-mentioned standards.