Site Effects of Taipei Basin

Presenter:Yi-Wun Liao

Date: 2013/10/24

Abstract

The Taipei basin has a flat surface structure. The subsurface structures inside the Taipei basin consist of Quaternary sediment layers on the Tertiary basement rock. In order to understand how the sediment layers influence the site effects in Taipei basin, we first used the method of amplitude spectrum ratio to obtain amplitude contour at some periods the dominant frequency distribution. Second, we calculated PGA (Peak ground accelerations) and response spectra for the Taipei basin region by using stochastic simulation technique on the basis of the empirical soil/rock spectral ratios we obtained.
As the result, sites in the western part of Taipei basin have lower dominant frequencies and the higher frequency PGA occurred at the edges of the basin. Varieties of the sediment layer structure can also effect the dominant frequencies at each site. Our empirical spectral ratios can help us to predict PGA distribution successfully. However, we still need earthquakes at different azimuthal angles to be counted in.

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