1. A model for estimating amplification effects on seismic hazards and scenario ground motions in southern Ontario
- Author
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Braganza, Sebastian and Atkinson, Gail M.
- Subjects
Earthquake intensity -- Research -- Models ,Seismological research ,Earth movements (Geology) -- Research ,Engineering and manufacturing industries - Abstract
Site amplification effects in southern Ontario are highly variable and strongly influence felt effects and damage potential. Site parameters such as shear-wave velocity in the top 30 metres of soil ([V.sub.S30]), traditionally used to estimate site amplification, are not well known in this region. Thus, regional maps of shaking potential and seismic hazard are often overgeneralized. In this study, a site amplification model based on peak frequency ([f.sub.peak]) is compared to one based on [V.sub.S30], as given by the 2015 National Building Code of Canada (NBCC). Earthquakes and scenario events are used to estimate ground motions and shaking intensities. It is shown that both models generally predict similar felt intensities but show significant differences in their predicted amplification of ground motions as a function of frequency. The results of this study support the use of [f.sub.peak] as a site response variable for estimating amplification effects in southern Ontario. Key words: site amplification, [f.sub.peak], [V.sub.S30], NBCC. Les effets d'amplification a un endroit donne au sud de l'Ontario sont hautement variables et influent fortement sur les effets ressentis etlacapacite d'endommagement. Les parametres aun endroit donne tels que la vitesse d'onde de cisaillement aux 30 metres de couche superieure de sol ([V.sub.S30]), traditionnellement employee pour estimer l'amplification a un endroit donne, ne sont pas bien connus pour cette region. Ainsi, on generalise souvent excessivement les cartes regionales de possibilite de mouvement du sol et d'alea sismique. Dans le cadre de cette etude, on compare un modele d'amplification a un endroit donne fonde sur la frequence maximale ([f.sub.peak]) a un modele fonde sur la vitesse d'onde de cisaillement aux 30 metres de couche superieure de sol, tel que presente par le Code de national du batiment du Canada (CNBC) de 2015. Des tremblements de terre et des evenements de scenario sont utilises afin d'estimer les mouvements de sol et les intensites de tremblement. On montre que les deux modeles prevoient generalement des intensites ressenties semblables, mais ils presentent des differences significatives au niveau de leur prediction d'amplification de mouvements du sol en fonction de la frequence. Les resultats de cette etude appuient l'utilisation de la frequence maximale comme une variable de reponse a un endroit donne pour evaluer les effets d'amplification au sud de l'Ontario. [Traduit par la Redaction] Mots-cles: amplification a un endroit donne, [f.sub.peak], [V.sub.S30], CNBC., Introduction The intensity of ground shaking that a locality experiences in any particular earthquake can vary considerably from site to site. A good example of this phenomenon is the moment [...]
- Published
- 2017
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