Performance‐based assessment of seismic‐resilient steel moment resisting frames equipped with innovative column base connections

Abstract

Low‐damage and self‐centring column base connections have been proposed in the last two decades as innovative solutions able to provide the seismic resilience in Moment Resisting Frames (MRFs). Although many works have demonstrated the benefits deriving from the adoption of these systems, only a few research studies investigated the significant parameters influencing their self‐centring capability. This paper investigates the influence of the frame layout (i.e., storeys and bays number) on the seismic performance of perimeter MRFs equipped with damage‐free self‐centring column bases previously studied by the authors. Nine case‐study perimeter steel MRFs are designed and modelled in OpenSees. Incremental Dynamic Analyses are performed monitoring both global and storey‐level Engineering Demand Parameters, including peak and residual interstorey drifts. Fragility curves are subsequently used to evaluate the self‐centring capability of the structures. The present study provides insights on the use of the adopted connections for the residual drift reduction of MRFs and defines the boundaries of the investigated parameters for their application. Results highlight that the self‐centring behaviour is particularly sensitive to the number of storeys and tends to reduce with the increasing height of MRFs equipped with the proposed connections.