Correlation of damage of steel moment-resisting frames to a vector- valued set of ground motion parameters

Abstract

Seismic risk analysis extends probabilistic seismic hazard analysis (PSHA) so as to quantify potential threats in terms that stakeholders are most interested in, such as monetary losses, injuries and deaths, and/or recovery time. The interface between PSHA and risk analysis is the ground motion parameter (GMP), which characterizes the ground shaking at a site in terms of at most a few quantities. The most commonly used GMP, of course, is pseudo-spectral acceleration (Sa). For structures whose response is (i) not highly ine- lastic and (ii) governed by a single fundamental mode of vibration, Sa is clearly a useful GMP, due to its strong correlation with the response of such structures. However, for many other structures, alternative GMPs that account for the effects of inelasticity, higher modes of vibration, and energy considerations can prove to be even more useful. The study described in this paper investigates the correlation of such alternative GMPs with the response (and thereby damage) of model steel moment-resisting frame buildings. A vector of GMPs that includes Sa, higher-mode pseudo-spectral accelerations, and an inelastic fundamental-mode spectral ac- celeration is demonstrated to be particularly promising. 1 MOTIVATION