An integrated approach for evaluating “site-dependent” seismic hazard in terms of ground-motion parameters, which are used for engineering purposes, is presented. The method is based on the probabilistic seismic hazard analysis in terms of Fourier acceleration spectra. A scheme that allows conversion of the Uniform Hazard Fourier spectra to “hazard-compatible” peak ground acceleration (PGA), and Uniform Hazard response spectra is described. The method has been applied for preliminary probabilistic microzonation of the Taipei basin (the Taipei city). The source, path and site effects are characterized separately on the basis of the analysis of large collection of ground-motion recordings obtained since 1991 in Taiwan area. The probabilistic microzonation maps of the Taipei basin were compiled for various return periods and were compared with the data from recent strong earthquakes. It has been shown that Peak Ground Acceleration and amplitudes of the Uniform Hazard Response spectra strictly depend both on the local site conditions and on the characteristics of seismicity (the depth and location of earthquakes, and azimuthal direction of incident excitation). Therefore, one single building code is not adequate for the whole basin area. The obtained “Region & Site & Return period-dependent” estimations may be used as a reliable basis for building code provisions and engineering decisions
