ABSTRACT This paper illustrates opportunities for the use of simulated ground motions in seismic performance assessment – from seismic hazard, ground‐motion selection, response history analysis, and seismic demand hazard calculation. The illustration is through a comparative analysis with the conventional alternative of observed ground motions. Three different approaches for using simulated/observed ground motions are identified, and the impact of these alternative approaches on seismic risk is examined via the response of a 12‐story structure (located at a site in the South Island, New Zealand) subjected to 20 ground motions selected for seven intensity levels. Structural response is quantified via peak floor acceleration and peak inter‐story drift ratio and seismic risk is compared and contrasted in terms of demand hazard and collapse risk. The results indicate that the manner in which the seismic hazard is computed is the defining factor in the seismic risk results. That is, the largest differences were obtained between the cases where seismic hazard was obtained using conventional empirical ground‐motion models as compared to ground‐motion simulation‐based seismic hazard analysis. There was a relatively smaller effect of ground‐motion selection using either simulated or observed ground motions, when the target intensity measures that the ground motions were selected to match are based on seismic hazard using empirical ground motion models. This highlights that both (i) simulated ground‐motions are a simple substitute for observed ground motions for scenarios which are poorly represented in observational ground motion databases; and (ii) seismic hazard analysis using simulation‐ and empirical‐based ground‐motion models can exhibit appreciable differences, and improvements in both types of methods is a valuable opportunity for further research.
Loghman et al. (Wed,) studied this question.