Influence of repairable bolted dissipative beam splices (structural fuses) on reducing the seismic vulnerability of steel-concrete composite frames

Abstract

After a strong earthquake, repair work of conventional steel-concrete composite buildings can be very expensive, and very often, impossible due to practical problems. Within the EU-funded research project FUSEIS, a new steel-concrete composite frame type has been developed, as a cost-effective and robust alternative to conventional earthquake resistant structures. In this new frame type, damage concentrates mainly in the bolted dissipative beam splices acting as “structural fuses”, which can be easily and inexpensively replaced after strong seismic events. After the replacement, the building can be restored to its original form. This paper studies a benchmark building frame with and without bolted dissipative beam splices. The performance of both innovative and conventional structures has been quantified in terms of energy dissipation, floor displacements and inter-story drifts, as a result of nonlinear transient dynamic analysis. Different than similar studies in the literature, the numerical models explicitly consider the presence of reinforced concrete slab by means of fiber-based distributed plasticity approach. They have been calibrated according to the experiments, both provided in the literature and performed in the FUSEIS research project. The models allowed the quantification of the energy dissipated by each component of a steel-concrete composite frame (structural fuses, steel elements, concrete slab and steel reinforcement), which gave an insight on redistribution of dissipated energy in the case of adopting the structural fuses with respect to the traditional steel-concrete composite buildings. Based on the results of the numerical analysis, the reparability aspect has been discussed.