Abstract
The present paper proposes a ratio of effective acceleration A0 to PGA(A0/PGA) to evaluate periodic characteristics of earthquake ground motion by using JMA seismic intensity and PGA. A relationship between A0/PGA and spectrum of earthquake ground motion was theoretically studied. It is clarified that the shape of spectrum of earthquake ground motion correlate with A0/PGA. Next, a relationship between A0/PGA and peak period of fourier and velocity response spectrum were examined. Moreover, it was found that A0/PGA have a positive correlation to the relative amplitude of spectrum for period 1 to 2s. Finally, we proposed an equation of the average amplitude of velocity response spectrum for period 1 to 2s(Sv1-2) as parameters of A0/PGA and logA0. We verified that the proposed equation can evaluate Sv1-2 more accurately than that using only logA0 or logPGA.
