Published works

This paper presents a technique for constructing analytical fragility curves for generic URM components such as parapets and façade walls subjected to out-of-plane actions. The technique implements a nonlinear time-history-analysis (THA) that computes the wall’s displacement history under generic shaking input. The model defines the wall’s capacity by a force-displacement model that neglects tensile bond strength and assumes that all resistance comes from rocking stability and, where applicable, friction. Synthetic accelerograms compatible with the AS 1170.4-2007 soil class D spectrum were used as the ground motion, and the acceleration input applied at the component level was computed by a precursor THA of the building to account for its motion-filtering influence and height amplification. Fragility curves were generated for several different wall configurations including parapets, one-way and two-way spanning walls. The generated curves are used to examine three alternate force-based approaches permitted by AS 1170.4. It is shown that the code techniques are unreliable in estimating the ground motion intensity to cause collapse, and that they are in some instances overly conservative (uneconomical) while being unconservative in others.