Resumen:
Future necesity of implement several levels of design is established. The most important variables which defines the behavior of structures under seismic actions are identified and their influence in the structural behaviors is analyzed in order to obtain the risk spectra associated to a specific seismic hazard and structural vulnerability. Thus the assesment of the seismic demand associeted to any level of performance, which can be used either to desig new structures or evaluate existent structures
