Nonlinear analysis and experimental behaviour of an innovative steel frame with reinforced concrete infill walls

Steel frames with reinforced concrete infill wall (SRCW) are characterized by an high stiffness that minimize the inter-storey drift and the associated damage to non-structural elements. They are however characterized by critical drawbacks, that limit their use, such as the low dissipative capacity of the concrete wall that causes high seismic force and high overturning moment at the wall base foundation. Within the present study, an innovative steel frame with reinforced concrete infill shear wall system is proposed. It consists of a reinforced concrete infill walls surrounded by a steel frame which contains energy dissipation replaceable elements within the columns. In this way the force transmitted to the other structural elements, and in particular to the foundations, are limited and an important portion of the seismic energy dissipated through plastic deformation. Within this paper the behaviour of the proposed system is investigated through nonlinear analyses based on advanced models supported by the experimental results on real scale specimens, highlighting advantages and drawbacks of the system.