Inter-storey drift and storey shear forces in rocking isolated buildings

Research into the technology of isolation, or passive energy dissipation, to enable a fully modular building to perform satisfactorily in a destructive earthquake without relying on any form of external support has been reported in the literature. Tendon restrained rocking isolation which this study deals with is one of such innovations. Rocking isolation with tendon restraints serves the purpose of partially relieving the onerous demand on the structural elements and their connections. An important facet in the structural design of a rocking isolated building is in estimating the amount of seismic drift and storey shear that cannot be eliminated completely by the isolation. Recently developed analytical models for giving these predictions have been validated by the authors through shaking table testings. However, full details of the derivation of the predictive relationships have not been presented in any peer reviewed publication. As the design concept is new, structural designers would not have the confidence to apply the new methods in practice when their basis is not fully understood. This article is essentially to provide full details of the derivations of the relevant closed form expressions along with illustration by a case study filling in the knowledge gap. The aim is to enable designers to adapt the newly developed techniques in structural design practice.