**作者：**田堯彰**中文摘要：**The evolutionary power spectrum (EPS) of any single seismic accelerogram is estimated using two techniques. An appropriate normalization factor is adopted to build the shape function of the expected EPS of a particular set of accelerograms. The relationship between this factor and the peak ground acceleration (PGA) is investigated. Therefore, under a design g-level, the expected EPS is obtained by multiplying the shape function by a suitable normalization factor. Based on the expected EPS, a set of simulated acceleration time histories can be generated to calculate the response spectral values. The available data include 159 strong-motion records in Taiwan with PGA greater than 0.05 g. The data are classified according to site condition and earthquake duration. It is shown that, within the range of the periods of interest , the spectrum of the hard site obtained using the conventional method is not conservative. The spectra obtained using the two proposed methods are preferable for the design of some important structures and tall buildings.**英文摘要：**--**中文關鍵字：**design spectrum, evolutionary power spectrum, subprocesses technique, multifilter technique**英文關鍵字：**--