Valutazione della vulnerabilità sismica di edifici storici tramite l'analisi cinematica

Nonlinear kinematic analysis represents a higher level of refinement respect to linear kinematic analysis. According to nonlinear kinematic analysis in fact, since the capacity of the structure is evaluated in terms of displacements, the whole evolution of the collapse mechanism can be investigated, starting from the activation point to the collapse of the portion of building analyzed. By means of nonlinear kinematic analysis in fact the capacity of the structure is represented by a capacity curve, and not only by a value. The ultimate capacity, to be compared to the seismic demand, is then evaluated according to the Italian building code prescriptions. Hence nonlinear kinematic analysis takes into account for hidden capacity of the structure and for a more realistic behavior of the structure itself. In the thesis the seismic verifications results, for both linear and nonlinear kinematic analysis, are expressed in terms of a seismic safety index, defined as the ratio between the capacity and the demand. Hence, if the seismic safety index is higher than one, the seismic verification is satisfied, otherwise, it can be stated that the portion of building analyzed is vulnerable with respect to the collapse mechanism calculated. If so, an intervention plan can be proposed in order to increase the seismic safety level of the building towards the local collapse mechanisms analyzed. As anticipated, since local collapse mechanisms are investigated, the same building can be subjecte