Seismic Assessment of RC Existing Irregular Buildings

In the paper the seismic assessment of a set of reinforced concrete framed structures representative of real existing buildings designed only to vertical loads has been carried out. In particular, structural types having different positions of the stiff staircase structure which determine in-plan irregularity have been studied (3 cases: NS, CS and ES). Further, structural types having different number of storeys (2 cases: 2 and 4), presence and position of masonry infills (3 cases: bare, infilled and pilotis frames) and concrete strength (3 cases: 10, 18 and 28 MPa) have been considered. Non-linear static analyses according to the Italian seismic code on 3D models designed taking into account the presence of staircase structure and of masonry infills have been performed. The results show the remarkable role of in-plan irregularity and of masonry infills on the seismic performance of existing buildings