Safety and reliability of structures including ductile and brittle elements

Nowadays, for many countries in seismic areas, the maintenance of the architectural heritage is an essential priority. In Italy for example, the 90 % of the built up areas are more than 30 years old and the problem of the seismic assessment an rehabilitation of the existing buildings is somehow crucial, due to the coming into force of a new generation seismic code adopting definitely higher safety standards than the previous. In this framework, the authors present a first analysis of the seismic reliability of a number of low-rise ordinary masonry buildings, sorted with different geometrical and mechanical properties and different ages. The analysis is then repeated by considering the main shear wall of the buildings strengthened with fiber rein-forced polymers (FRP) reinforcements. Typically, masonry shear wall systems behaves like a low-ductility parallel systems, which exhibit a somewhat redundancy. When brittle behavior structural reinforcements like FRP are introduced, the system ductility decreases together with the residual redundancy, and the reliability outcome does not increase as expected. The obtained results allow very interesting considerations on the reli-ability of the existing masonry structures and the effectiveness of this strengthening technique when applied to masonry shear wall systems.