INNOVATIVE SEISMIC PROTECTION OF EXISTING BUILDINGS BY MEANS OF DISSIPATIVE AND SHAPE MEMORY ALLOY BRACES

The characterization, conservation and securing of heritage buildings has become a very important issue in many countries, as it is in Italy, where a great number of existing constructions, also of historical-artistic importance, are seismically vulnerable. Knowledge of the history, and geometric and mechanical characteristics are fundamental aspects to assess the state of a construction and to analyse possible interventions. In the first part of this thesis, the techniques of survey and mechanical characterization of the materials are analysed, and the costs of carrying out the materials’ tests to reach two different levels of knowledge on a case study building are calculated. Then the thesis focuses on the use of energy supplementary dissipation systems for seismic protection of existing buildings. The effects of using systems of this type on two Reinforced Concrete (RC) existing buildings, in terms of force reduction, energy absorbed and torsional stiffness, are evaluated. Moreover, analysis of Shape Memory Alloys (SMAs), smart materials capable to undergo large deformations and go back to the initial shape, is performed. Different types of SMAs are taken under consideration for possible applications in RC structures. The benefits that can be obtained by their use in an existing building are also evaluated. Finally, the main aspects and benefits related to the transition from the current traditional design of buildings towards the BIM methodology and the use of BIM also in the field of existing constructions are discussed.