Analysis and seismic retrofit study of a heritage-listed R/C elevated water tower

A heritage-listed R/C water tower designed by the world-famous Italian engineer Pier Luigi Nervi and built in the early 1930s, representative of a wide stock of heritage-listed elevated liquid storage tanks with frame staging, is examined in this study. The assessment analysis of the structure is developed with a detailed finite element model, which includes a multi spring-mass assembly to reproduce the fluid–tank dynamic interaction. The time-history evaluation enquiry shows collapse response conditions under seismic action scaled at the maximum considered earthquake (MCE) level. Based on these data, a passive supplemental energy dissipation-based retrofit hypothesis is proposed, consisting of the installation of a dissipative bracing system incorporating pressurized fluid viscous spring-dampers. The installation details the protective technology, and the benefits induced in the seismic response of the tank structure are discussed. Costs are also estimated and compared with the costs of a conventional nondissipative bracing retrofit solution developed for the same performance.