Vulnerability of Elastomeric Bearing Isolated Buildings and Their Equipment

In this paper, we compare the vulnerability of isolated and conventional structures as well as equipment when uncertainty on the excitation and on some of the structural properties is considered. This comparison is performed, mainly, with a series of Monte Carlo simulations. The results clearly show the higher sensitivity of isolated structures and their equipment when submitted to statistically reasonable excitations that are different from those used for their design. This fact is recognised by some, but not all, earthquake regulations, mainly, by considering lower behaviour factors for isolated structures than for conventional ones. Although isolated structures designed according to these recommendations (e.g. FEMA 368) exhibit tow damage less frequently than conventional structures, the probability of failure is similar for both types of structure.