Spectral Ground-Motion Predictive Model for Algeria Considering Site Effect Based Hvsr


Abstract eng:
A local site condition profoundly affects the ground motion record characteristics, and has an important impact on the accurate of the empirical ground motion prediction relations. Based on a large database containing 1555 records homogeneously processed with more than 600 recorded in Algeria and the rest from essentially Mediterranean region, this study aims to develop a spectral ground motion predictive model for Algeria which has experienced several destructive earthquakes in the past. As for Algerian tectonic environment, only shallow earthquakes were included. The data ranges are 5 to 150 Km for distance, and 3.0 to 7.8 for magnitude. The considered spectral attenuation model accounts for geometrical spreading, anelastic attenuation, and geological site conditions. The regression method, introduced by [1], is a two-step inversion [2, 3]. The attenuation model describes the evolution of spectral acceleration according to magnitude, hypocentrale distance, and category of the site. The site classification is based on the predominant period computed using average horizontal to vertical response spectral ratio. Four site categories are defined according to [4] classification scheme. Because of the reduced number of records for very soft soil, we consider three soil types for the calculation of the empirical ground motion prediction relations: rock, firm and soft. Spectral attenuation laws were derived from 1555 horizontal components. The introduction of a more accuracy site classification leads to significantly lower prediction of average spectral acceleration at rock site. Moreover, in Algeria, unlike the seismic zones 3 and 2b, which are characterized by moderate to high seismic activity, for areas with low seismicity as it is the case for seismic zones 1 and 2a who represent a broad range of Algerian territory, considering a low magnitude equal to 5.0, leads to significantly higher prediction of average spectral acceleration.

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Conference Title:
Conference Title:
16th World Conference on Earthquake Engineering
Conference Venue:
Santiago (CL)
Conference Dates:
2017-01-09 / 2017-01-13
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Text je chráněný podle autorského zákona č. 121/2000 Sb.



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 Record created 2017-01-18, last modified 2017-01-18


Original version of the author's contribution as presented on USB, paper 127.:
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