Influence of ground motion duration on collapse risk: spectral shape-amplitude scaling joint effects
Journal
World Conference on Earthquake Engineering proceedings
ISSN
30065933
Publisher
International Association for Earthquake Engineering
Date Issued
2024
Type
text::book::book part
Abstract
In performance-based earthquake engineering, addressing collapse risk has been a main concern among researchers and engineers, and the influence of ground motion duration on collapse risk has been widely studied in the past years. Additionally, recent research has shown that spectral shape has a strong influence and that amplitude scaling using large scaling factors in the selected ground motions tends to introduce a bias on the estimation of inelastic displacement demands and in the probability of collapse. However, the combined influence on these parameters has not been previously assessed. In this study, nonlinear response history analyses have been conducted on a series of single degree of freedom systems (SDOF) with degrading bilinear hysteretic response. Ground motions were selected in order to represent a combined hazard of subduction and crustal events. Thus, databases of the NGA-West2, Chile’s Strong-Motion Database, and Japan’s Strong-Motion Seismograph Networks were used in this study. Following recommendations of previous studies, ground motion duration was quantified using the 5-75% significant duration (SD5-75) while the effect of spectral shape was considered by selecting records with the least mean squared error with respect to a target response spectrum computed using only unscaled ground motions. Results suggest that, while it is evident that inelastic displacement demands and the collapse probability tend to increase as SD5-75 increases, the combined use of long duration acceleration time histories and large scale factors exacerbates this effect in the case of short and intermediate period systems. Conversely, the use of large scale factors does not seem to increase structural demands in the case of long period systems.
License
Acceso Restringido.
URL License