Selection and scaling of 3-component ground motion suite for scenario- and intensity-based assessment of buildings and structures

Abstract

Ground motion selection and scaling to match both horizontal- and vertical-target spectra are somewhat unclear in state-of-the-art. Two questions often arise: (i) which target spectra (vertical/horizontal/both) should be used for ground motion selection? and (ii) whether the same or different scale factors to be used for the horizontal and vertical components? This paper is primarily aimed to address these two issues. Seven possible options of ground motion selection and scaling arising through the horizontal- and vertical- target spectral-pair with a provision of same- and different-scale factors are studied to find the best alternative. Hazard consistency between the target spectral pair is investigated and compared with state-of-the-art to identify the possible misconception. Selection of conditional mean spectra (CMS) of horizontal- and vertical-components of ground motion should be consistent without which the inclusion of conditional spectra (CS) may not be physically realizable. Possible manifestation of inconsistent CMS of horizontal- and vertical- ground motions in the resulting engineering-demand parameters is also investigated.