Lateral-resisting systems capable of multiple seismic performances

This paper aims at presenting an innovative approach for an optimised/full-controlled seismic design of structures which combines recent contributions in the field of earthquake engineering and overcomes the traditional design approach leading to the identification of the characteristics of the lateral-resisting system capable of satisfying multiple seismic performance objectives. In this respect, it is fundamental the total conceptual separation between the structural systems resisting to vertical and horizontal loads. With reference to both (1) a braced pendular frame structure and (2) a shear-type frame system coupled with a lateral-resisting element (such as a reinforced concrete core or a bracing system), the approach here presented identifies the characteristics (strength, stiffness, ductility, energy-absorption) of the system resisting to horizontal loads which enables to satisfy prescribed seismic performance objectives. This is achieved through the identification of an objectives curve, in the Force-Displacement diagram, of the mechanical characteristics of the structure. The lateral-resisting system is obtained by means of (1) special braces in the case of the braced pendular frame structure and (2) special connection elements in the case of the shear-type system coupled with a lateral-resisting element