Seismic assessment of existing RC structures: non linear analyses of different building typologies.

The crucial issue of assessing the seismic vulnerability of RC structures has recently gained the attention of both the scientific community and professional engineers, due to the aging of several existing buildings and the development of earthquake engineering in terms of codes provisions. Among the available analysis procedures, emphasis is put in this paper on the non-linear static methods, considered a reasonable compromise between the linear procedures and the more realistic and complex non linear dynamic methods. In particular, attention is focused on the lumped plasticity approach, which is also commonly used by codes and guidelines and can be followed for both the seismic design of new buildings and the assessment of existing ones. Finally the fiber model approach is investigated and compared with the lumped plasticity one.