STRUCTURAL ANALYSIS FOR AN HISTORICAL R.C. TALL BUILDING RESTORATION

n this paper a detailed structural analysis (under the seismic and wind loads) of an historical tall building in Milan is carried out. It’s one of the first tall building (109 m height) realized in Italy in the 56- 59 years, and an important restoration is affecting it with intended use change (from office to luxury hotel and residences). To investigate the characteristics of concrete several destructive, non-destructive and combined tests are conducted. Moreover, additional destructive and chemical tests on the reinforced bars steel are performed too. Some finite elements models (FEMs) are implemented by using beam and plate elements considering two different boundary conditions (base fixed and elastic soil by Winkler model) and the interaction of the close existing lower constructions presence. In all of the FEMs, the materials characteristics are assigned basing on the tests results and a their subsequent statistical interpretation. The seismic load, implemented by a response spectrum analysis, and the wind load are applied in according to the Italian Construction Code (NTC). The structural resistance verifies are carried out in terms of shear and combined compressive-bending stress, whereas further ductility verifies are conducted considering appropriate nonlinear behaviours of the concrete and the steel bars. Finally some hypothesis to improve the structural behaviour under the lateral loads are proposed by considering cost-benefit analysis.